1952 lines
65 KiB
Plaintext
1952 lines
65 KiB
Plaintext
COMPUTER SECURITY
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-----------------
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Notes of the presentation to
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The Institution of Production Engineers
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March 21, 1990 by
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E.A.Bedwell, E.D.P. Specialist
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ORTECH International (NRC/IRAP)
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2395 Speakman Dr., Mississauga L5K 1B3
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(416) 822-4111, Ext. 261
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The writer wishes to thank the Institution of Production Engineers and
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it's President for the invitation to make this presentation, and to
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express sincere appreciation to David Stang, Ph.D., Director of Research,
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National Computer Security Association, for his contribution both to this
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paper and to computer security in general. And I would be very remiss if
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I neglected to mention the professional secretarial assistance provided by
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Jane Templeman, who makes our whole team tick like the NRC official time
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clock - the one that gives the CBC time signal.
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This document is, hopefully, written softly: after all, it might be
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easier to digest if I have to eat my words. I do not profess to be "the
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expert" in the field of computer security; an expert is someone who knows
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more and more about less and less until s/he knows absolutely everything
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about nothing. I hope never to stop learning, which means (thankfully)
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I'll never be an expert.
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INDEX PAGE
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----- ----
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1. Definition/Scope of "COMPUTER SECURITY" 2
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2. Why Should You Be Concerned? 2
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3. Types of Security Breaches 3
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4. Reasons for Exposure 7
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5. General Security Rules (all computer systems) 8
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6. Viruses: 9
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6.1 History 9
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6.2 Effect 10
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6.3 Why do people do it? 10
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6.4 Symptoms 10
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6.5 Concerns 11
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6.6 Known Virus Software (1) 11
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6.7 Quick Guide to Virus Names (1) 12
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6.8 Table of Virus Effects 16
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6.9 Virus Detector/Antidote software 19
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6.10 Trojan Horses 20
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7. PC Rules of Thumb 22
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8. Easy Tricks for PC Security 23
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9. So You're Infected (Cure) 24
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10. Summary: What Can You Do? 25
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11. Security Policy: Points for Consideration 26
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12. To run SCAN (included on this diskette) 29
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(1) David Stang, Ph.D, "Network Security in the Federal Government,",
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January, 1990, p.168-169 (updated by E.A.Bedwell, March, 1990)
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- 2 -
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Tonight's topic is "Computer Security," a subject near and dear to my
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heart after catching fraud a few times, and cracking system security a
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few times. The only unfortunate part of this evening is that I have
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enough material to cover an intensive 2 or 3 day seminar and I only have
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something over an hour, so in addition to extensive notes from this
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presentation, I've put an article on viruses, and a PC virus detector
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program on diskette for you.
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1. SCOPE OF COMPUTER SECURITY
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Computer security relates to any potential loss of information or your
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ability to operate, regardless of the source of the problem. Of course,
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all the publicity about computer security is going to the virus
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situation. I don't want to dissuade anyone from their concerns about
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viruses, because it's definitely a growing problem, and if you get hit,
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you'll be sorry you ever laid eyes on a computer. But, current estimates
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indicate that viruses represent only 3% of all the computer problems now
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occurring. Of course, if you're one of the 3%, like CNIB or Barclay's
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Bank Canada were last fall, you'll feel like you're the only one on
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earth. The difference between viruses and other computer security issues
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is apparently one of control: I hope to convince you that you have as
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much control over viruses and as little control over the other 97% of
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problems as to make them equal threats to the safety of your computer.
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I'm going to get to viruses later, their prevention, detection and cure,
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but I'd like first like to cover the other major problems that affect
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computer security - the other 97% - and I'd like to start with reasons
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why you should be concerned about security.
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2. WHY SHOULD YOU BE CONCERNED?
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Your data is a valuable asset, just like premises, equipment, raw
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materials and inventory. Because so much of modern business depends on
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computers - financial systems, engineering design, medical diagnosis,
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production and safety control - the destructive potential is greater
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every year. There has been more than one company that's suffered great
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losses, and even gone under because of the loss of things like their
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accounts receivable records: no one is going to pay you if you don't
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send them a bill, and if they get word of your inability to invoice them,
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their darned unlikely to volunteer payment - so you're in a financial
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mess. The same goes for your design information, production data, the
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consequences if safety control systems malfunction, or even the simple
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loss of your customer list.
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Another reason why you should be concerned is, too often, people don't
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think about computer security until it's too late. There's a saying in
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my industry that, "He who laughs last probably made a backup." Another
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saying is, "Experience is something you don't get until just after you
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needed it the most." Well, if it means the life of your company, or the
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loss of potentially millions of dollars, or even just the information on
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your home computer, it might be wise to get at least some basic knowledge
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before the disaster strikes.
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- 3 -
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3. TYPES OF SECURITY BREACHES
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Now that the 'why' is out of the way, let's break down the 97% of
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problems. These are not in a specific order, but just as they came to
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me. Nor have I attempted to attach percentages to each type of risk,
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because very few computer crimes are actually reported, so any figures
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that anyone could estimate would not be realistic:
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FRAUD/THEFT
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By far the biggest problem is fraud or theft. Some examples of this are:
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CHAOS - 1987 - Hamburg -> NASA data bank info sold to USSR
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Foreign exchange } famous because of big $
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Electronic Funds Transfer } amounts, and because of the
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Insider Trading } publicity they've received
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Most common: Cookie jar technique - e.g., interest, income tax
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(aka 'Salami' technique - take a little and no one
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will notice)
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Specific examples I've caught were in Payroll (no crash on < or =),
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Accounts Payable (dummy companies), Purchasing (failed reasonableness
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test), and Accounts Receivable (failed balance routine). These were all
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thefts of money.
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Another example of theft which is very interesting is the 28-year-old
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Canadian who was arrested at UNISYS in Pittsburgh on Dec. 13/89 - what he
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is alleged to have stolen was NCR's trade secrets - to the tune of
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US$68M, which comes under a different Canadian law from monetary theft.
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MALICIOUS DAMAGE / VANDALISM
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The next major type of computer security breach is the disgruntled
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employee syndrome. Their favourite is the logic bomb or time bomb: on a
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certain date or condition after they leave the company, something's going
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to happen, such as at the health centre in LA where all prescriptions
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suddenly multiplied by 2. That's really serious, even compared to the
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logic bomb that superzaps all your files off the face of the earth,
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because someone could die. At least with a superzap, you can recover if
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you've been backing up and have a disaster recovery plan in effect. Pure
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physical vandalism occurs more often at educational institutions, but is
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still a serious threat. I wouldn't let me near your machine if I was
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angry with you - my vandalism would be difficult to detect (and expensive
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to repair). A simple application of a magnetized screwdriver ......
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LACK OF SECURITY PLANNING IN SYSTEM DESIGN STAGE
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One of the biggest logic bombs that's going to occur is on January 1/2000.
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Do you know how many computer systems use a 2 digit number for the year?
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Do you know how much work it's going to be to adapt systems to recognize
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00 as being greater than 99? My grandmother was born in 1886, and most
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systems show her birth year as 99. If she lives to the year 1999, I
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wonder if they'll start sending her the baby bonus. This time bomb is not
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malicious damage, it's pure lack of planning at the system design stage.
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- 4 -
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(Lack of Security Planning - continued)
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Things like balance checks and reasonableness tests are not built into the
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system from the beginning, and it's not easy to put them in later. Users
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must participate at the system design stage, because only they know what's
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reasonable and what can be balanced. Don't expect a computer technician
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to know everything there is to know about your job.
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DISTORTED SENSE OF HUMOUR
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Then there's the practical joker - the one who thinks it's funny to break
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into the system to see what he can change, or create some dumb message to
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appear on your screen. That's what happened at IBM when the infamous
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Christmas tree appeared 2 years ago (1987). The joke was three-fold -
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first it analyzed your electronic mail distribution lists and reproduced
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itself to send to everyone you normally send messages to - this clogged
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the system up with people reading more messages than normal. The second
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part was a little more technical - everyone who read the message caused a
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separate load of the offending program to take up space in memory, unlike
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most systems where two or more people who are doing the same thing are
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sharing one load of the software. This clogged memory up so that nothing
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else could run. There was one more part to this: there were delay timers
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built into the program so it deliberately ran very slowly. The result was
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that the largest computer network in the world was shut down for 4 hours.
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Someone must have had a great need for a power trip.
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MISTAKE
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Next, there's fumble fingers: you know, the one who keys the formula in
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as 600 grams instead of 60 grams, or the estimated production time of 2
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hours instead of 2 days. Or the one who almost took me into court when
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he blamed "the computer" for a mistake. Without going into details about
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that incident, I can say that going through the grilling by several
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lawyers in a preliminary investigation was not the high point of my
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career. What saved the situation (for me and the organization) was audit
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trailing: every time a transaction was entered, the system recorded the
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terminal i.d., the user i.d., the date and the time. It also saved a copy
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of the record as it existed prior to the transaction taking place. A more
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common mistake, though, is to unlatch a diskette door before the light
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goes out. Few people realize that the FAT (file attributes table) is the
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last thing written on a disk, and you can corrupt the FAT by removing the
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disk too early.
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"EVERYONE DOES IT" SYNDROME
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Then there's everyone's favourite: copying software. Believe it or not,
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in Canada, that falls under the Copyright law, not under theft, but it
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has been successfully prosecuted. Even if you reverse engineer it and
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make some minor changes, it will come under the "look and feel" test of
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the Copyright law - if it looks and feels the same as the original, you
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can be prosecuted. Copying software is illegal, and your company as the
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registered owner could be held liable if it is detected.
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- 5 -
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ILLEGAL ACCESS
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Many major computer crimes are perpetrated by illegal access: the 14-
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year old who broke into NASA from his basement computer room is just one
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example. There is password software on all larger machines, and it's not
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difficult to put it on PCs. On the larger machines, one of the major
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problems is not changing the standard passwords that are set when the
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machine is delivered: the standard user-level password may be USER, the
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standard operator password may be OPERATOR, and the standard field repair
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person's password may be REPAIR, and so on. Guess how I've cracked
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security a couple of times. In a 1988 article by Dr. Cliff Stoll in
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"Computers and Security,", he reported that in 10 months of systematic
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testing on computers attached to the US Defense Data Network (Milnet),
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access was gained in 13% of the attempts simply by guessing at passwords!
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There should be some rules applied to passwords: not less than 7 or 8
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characters, must be changed at least every 60 days, don't use common
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things like names (another way I've broken security), don't share it
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under any circumstances and, for heaven's sake, don't post it on the
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front of your machine or leave it where someone can find it. It's your
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personal PIN - just like the money machine - and the information you're
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dealing with is worth money. Some of the most difficult passwords to
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break (take it from me) are "two words reversed" (e.g., boardwall,
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hornshoe, cuptea), or foreign language words (e.g., coupdegrace,
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millegrazie, caliente). Nonsense is good, too: geebleurql is nice.
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If you're installing password security on a PC, consider whether you
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should have it so tight that there is no recourse to the DOS level or no
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ability to boot from the A: drive. You'd need really good password
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software (or a good technician on staff) if you have both of these
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facilities - otherwise you can lock yourself out - but it's my preference
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(especially for the guy who's wiped his root directory twice).
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PHYSICAL SECURITY
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Finally, another area that affects computer security or your ability to
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carry on computer operations, and one that is often overlooked, is simple
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physical security: keys, thermal shock, vibration, dirt, water, fire,
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visibility of information, steady power supply, discharge of static
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electricity, magnetic fields, are all relevant to security. We have one
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man in our network who should have (a) cabling bolted to his computer and
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the floor, (b) a key to his unit, and (c) dust protectors (as well as
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password access only without recourse to the DOS level).
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When it comes to thermal shock, if you work in an area where the heat is
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reduced on winter weekends, I strongly recommend you leave your unit
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running over the weekend - just lock the keyboard. If the air
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conditioning is shut down, turn your unit off, and don't turn it on until
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the temperature is 23C or less. And please don't leave your machine
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sitting in the sun, or in front of an open window to attract dust. The
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internal temperature raises within 20 mins. or so to >30C, and the effects
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of thermal shock are such that it can, first, rock memory chips out of
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their sockets, and, worse, misalign the read heads on your disk drive so
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that nothing can be read.
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- 6 -
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(Physical Security - continued)
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Vibration, too, is a source of problems, especially for drives. The read
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heads actually float over the surface of drives, not on them the way a
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record player needle does, and the space tolerance between is measured in
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Angstroms (metric version of microinches). Vibration can cause the head
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to hit the drive, and you can say goodbye to whatever was written there.
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If you're in a particularly sensitive field, and your information is what
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might be called top secret to your company, you might also want to look
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at two protection devices: one is encryption, and the other is Tempest
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hardware or shielding. Encryption involves translating your data using
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algorithms to something unreadable, and de-coding it when you need it. It
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uses a "key" to choose the algorithm - dont' lose the key! It comes in a
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few forms: software controlled encryption, hardware based encryption, or
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a combination of the two. Most encryptors work with standard algorithms,
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but defense departments and other high-security installations prefer
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random algorithms. Tempest hardware, or shielding, protects against
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sniffing of signals. ( Signal emanation surveillance is called
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"sniffing.") I don't have a computer here to demonstrate this, but if
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you take an old battery-operated transistor radio and set the dial to the
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bottom of the AM band around 520, try passing it within a foot of your
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computer. Your ear might not pick up the individual signals, but I assure
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you there's equipment that does. That's why the US Army was blasting rock
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music around the Vatican Embassy when Noriega was there - to mask signals.
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More important to the average user, though, is avoidance of electro-
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magnetic fields (such as ringing phones near a disk or disk drive), and
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having an automatic disk head 'parker' that moves the heads to a safe zone
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every few seconds. That way, something like a brief power failure is less
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likely to cause a "head crash" on the disk.
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Simple visibility of information is a risk. Recently I went to a bank
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with a court order in hand to give me access to an account. The clerk
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simply turned the terminal toward me and, if I'd wanted to bother, I could
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have had the account numbers of two other people with identical names.
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There is screen saving software that will blank your screen after an
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inactivity duration you choose, and personnel should be made conscious
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that unauthorized viewing of information is a security risk. And watch
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what your staff throw out on paper, too.
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When it comes to fire and water, there are two basic rules that everyone
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can follow: first, don't smoke around the PC, and second, don't feed the
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PC coffee and donuts. You might be able to save a keyboard or some parts
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with a bath in distilled water, possibly followed by drying with a warm
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hair dryer, but there's no guarantee. I prefer pure isopropyl alcohol -
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without the hairdryer so I don't get fried in the process. Don't blast a
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computer with a fire extinguisher if you can avoid it. If you do have a
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fire or a flood, though, you'd better have a tested disaster recovery
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plan, and your backups stored off-site.
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All of these issues are reasonably within your control: fraud, theft,
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disgruntled employees, practical jokers, fumble fingers, software copying
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and physical security, at least as much as the infamous viruses that are
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around, but let's take a look at why you're at risk.
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- 7 -
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4. REASONS FOR EXPOSURE
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Concentration of data in one place
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Instantaneous adjustment
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Alteration without a trace
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Lack of visible records
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Complexity of the system
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Networking
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Technical persons can befuddle
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General ignorance by non-techie and management
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Detection problems
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Lack of training
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Security checks in programs not specified
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Systems not documented
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Limited staff resource for programming/management
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No separation of duties
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Possibility of enormous losses remaining undetected
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Reluctance to report - Embarrassment
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Lack of sufficient evidence to prosecute
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Cost to prosecute outweighs recovery
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Company policy ("Press would have a field day")
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- 8 -
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5. GENERAL SECURITY RULES (All Systems, big and small)
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Disaster Recovery } Backup Backup Backup
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Plan } Restore (test it to make sure it works)
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Store your backup off-site (not in your car!)
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Physical security
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Password for access control (don't stick your password on
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the front of your machine!)
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Access to menu only - not to system control level
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Reasonableness tests
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Balance checks (rounding: up, down, (out?); cross-calculations
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Audit trails - all records (terminal i.d., user i.d., date and
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time stamping, history record retention)
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Fall-through coding (if it doesn't meet a condition, does it go to limbo)
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Payroll/Accounts payable: don't pay the same # twice
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Fault tolerance level supported (user friendly/hostile -
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balance between fault tolerance & productivity)
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Call back or no answer on dial-up systems
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UPS (Uninterrupted Power Supply, or allowance for graceful
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degradation) - or at least an automatic head parker
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Logical view rights (your user 'privileges' allows access only to the
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data you need to see, e.g., accounting clerks don't need to see
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production formulae)
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Multi-user environment: protection against deadly embrace
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Automatic logoff on inactivity timer / Screen saver
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Policy statement re purchasing/use/theft/illegal
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software, etc.
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Encryption (?) - don't lose the key!
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Shielding ("Tempest" hardware for secure systems)
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Educate users
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|
||
- 9 -
|
||
|
||
6. VIRUSES
|
||
|
||
As in medicine, a virus needs an 'organism' to which it may attach itself,
|
||
and a virus is 'contagious'.
|
||
|
||
In the case of computers, a virus is usually a destructive piece of code
|
||
which attaches to a working program, such as your word processor,
|
||
spreadsheet or CAD/CAM software. Viruses are usually written to detect
|
||
any load of a computer file that has an extension of .EXE, .COM, .OVL,
|
||
.BIN - such extensions representing executable programs. Often, the
|
||
virus loads itself into memory, then loads the program you just called, so
|
||
the virus is sitting at the front. Then when you exit the program, the
|
||
virus code calls for the re-writing of the program back onto the disk -
|
||
with the virus still sitting at the front. Other viruses simply go
|
||
straight into your boot sector, so they get loaded every time you turn on
|
||
your machine. Some do both.
|
||
|
||
However they 'hide', and whatever they attach to, they got to your machine
|
||
on an infected diskette. If you are infected and then copy your software
|
||
to use on another machine, guess what happens? Right! That's where the
|
||
'contagious' element comes in.
|
||
|
||
In 1989, more viruses were discovered than in all previous years. There
|
||
were over 110 at the end of the year, and 7 were discovered in December
|
||
alone. Sources have been from as far away as Pakistan and Bulgaria.
|
||
|
||
Only .004% have reported infections, but most are not reported. Consider
|
||
this: if only 1% were infected, that would be 1/2 million units in the
|
||
U.S. alone. At a cost ranging from $300 to $3,000 per unit to recover,
|
||
the problem starts to impact the economy as well as the productivity of
|
||
staff at your organization. It cost one Texas company US$10M to shut
|
||
down their 3,000-unit network for 4 days to find 35 infected units.
|
||
|
||
One of the major problems with viruses is that 90% of the users who
|
||
recover are re-infected within 30 days. One person at my organization
|
||
was re-infected 7 times in 2 months! Most reinfections occur for one of
|
||
two reasons (not necessarily in this order): your back-up was infected,
|
||
or it was a virus that hid in the boot sector on track 0, and track 0 is
|
||
not re-written by the standard "FORMAT" command (only a low-level format
|
||
will get rid of a track 0 virus). Be careful of some new software as
|
||
well: there has been more than one instance of shrink-wrapped software
|
||
being infected (software companies have disgruntled employees, too, it
|
||
seems).
|
||
|
||
|
||
|
||
6.1 HISTORY
|
||
|
||
1959 - Scientific American article about 'worms'
|
||
1963 - caught my first two frauds (Payroll & Accounts Payable)
|
||
1970 - Palo Alto lab - worm which directed activities
|
||
1982 - Anonymous Apple II worm
|
||
1984 - Scientific American CoreWare Series: held contest to
|
||
find the most clever/difficult to detect 'bug'
|
||
1987 - Apparent change from intellectual exercise to
|
||
dangerous activity.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 10 -
|
||
|
||
6.2 EFFECT
|
||
|
||
Massive destruction: Reformatting
|
||
Programs erased
|
||
Data file(s) modified/erased
|
||
|
||
Partial/Selective destruction: Modification of data/disk space
|
||
File allocation tables altered
|
||
Bad sectors created
|
||
If match with event, alter or delete
|
||
|
||
Random havoc: Altering keystroke values
|
||
Directories wiped out
|
||
Disk assignments modified
|
||
Data written to wrong disk
|
||
|
||
Annoyance: Message
|
||
Execution of RAM resident programs
|
||
suppressed
|
||
System suspension
|
||
|
||
|
||
|
||
|
||
|
||
6.3 WHY DO PEOPLE DO IT?
|
||
|
||
Financial gain
|
||
Publicity
|
||
Intellectual exercise
|
||
Terrorism/Fanaticism/Vandalism
|
||
Revenge
|
||
Just plain wierd
|
||
|
||
|
||
|
||
|
||
|
||
6.4 SYMPTOMS
|
||
|
||
Change in file size (Usually on .COM, .EXE
|
||
.OVL, .BIN, .SYS or .BAT files)
|
||
Change in update time or date
|
||
Common update time or date
|
||
Decrease in available disk or memory space
|
||
Unexpected disk access
|
||
Printing and access problems
|
||
Unexpected system crashes
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 11 -
|
||
|
||
|
||
6.5 CONCERNS
|
||
|
||
Variety: Virus vs Bug vs Worm vs Trojan Horse vs Superzapper
|
||
vs Trap Doors vs Piggybacking vs Impersonation
|
||
vs Wiretapping vs Emulation
|
||
Strains / Complexity / Growing Sophistication
|
||
Bulletin board use and free software
|
||
Largest threats from taking computer work home
|
||
Kids using same machine at home
|
||
Networked mainframe systems
|
||
Travel/airline computers (AA wiped out early 1989)
|
||
Work message systems (E-Mail)
|
||
POS terminals
|
||
Banking / Credit Cards / Money Machines
|
||
Income Tax records
|
||
Health records
|
||
|
||
|
||
**************************************************************
|
||
* Global disaster may be on the way *
|
||
* No specific laws to deal with malicious programming *
|
||
* No single national centre to gather data on infections *
|
||
**************************************************************
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
6.6 KNOWN VIRUS SOFTWARE
|
||
|
||
12 viruses (and their strains) account for 90% of all PC infections:
|
||
_
|
||
|_| Pakistani Brain
|
||
|_| Jerusalem
|
||
|_| Alameda
|
||
|_| Cascade (1701/1704)
|
||
|_| Ping Pong
|
||
|_| Stoned
|
||
|_| Lehigh
|
||
|_| Den Zuk
|
||
|_| Datacrime (1280/1168)
|
||
|_| Fu Manchu
|
||
|_| Vienna (DOS 62)
|
||
|_| April First
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 12 -
|
||
|
||
6.7 QUICK GUIDE TO VIRUS NAMES (Cross referenced)
|
||
|
||
Name Synonym-1 Synonym-2 Synonym-3 Synonym-4
|
||
|
||
1168 Datacrime-B
|
||
1184 Datacrime II
|
||
1280 Datacrime Columbus Day October 12th Friday 13th
|
||
1536 Zero Bug
|
||
1701/1704 Cascade Falling Letters Falling Tears Autumn Leaves
|
||
1704 Cascade
|
||
1704 Cascade-B
|
||
1704 Cascade-C
|
||
1704 Cascade-D
|
||
1704 Format 1704 Blackjack Falling Letters
|
||
1704 Blackjack 1704 Format Falling Letters
|
||
1808 Jerusalem Black Box/Hole Israeli PLO 1808/1813
|
||
1813 Jerusalem Black Box/Hole Israeli PLO 1808/1813
|
||
2086 Fu Manchu
|
||
2930
|
||
3066 Traceback
|
||
3551 Syslock
|
||
3555
|
||
123nhalf
|
||
405
|
||
500 Virus Golden Gate
|
||
512 Virus Friday 13th COM virus
|
||
648 Vienna DOS 62 DOS 68 Austrian
|
||
AIDS VGA2CGA Taunt
|
||
AIDS Info Disk
|
||
Alabama
|
||
Alameda Virus Yale Merritt Peking Seoul
|
||
Alameda-B Sacramento Yale C
|
||
Alameda-C
|
||
Amstrad
|
||
Anti
|
||
Apple II GS LodeRunner
|
||
April 1st SURIV01 SURIV02
|
||
April 1st-B
|
||
Ashar
|
||
Austrian 648 Vienna DOS 62 DOS 68
|
||
Australian Stoned New Zealand Marijuana
|
||
Autumn Leaves Cascade 1701/1704 Falling Letters Falling Tears
|
||
Basit virus Brain Pakistani Brain Lehore
|
||
Black Box Jerusalem Israeli Black Hole 1808/1803 PLO
|
||
Black Hole Jerusalem Black Box Israeli 1808/1813 PLO
|
||
Black Hole Russian
|
||
Blackjack 1704 1704 Format Falling Letters
|
||
Bouncing Ball Vera Cruz Ping Pong Bouncing Dot Italian virus
|
||
Bouncing Dot Italian virus Bouncing Ball Vera Cruz Ping Pong
|
||
Brain-B Brain-HD Harddisk Brain Houston virus
|
||
Brain-C
|
||
Brain-HD Harddisk Brain Houston virus Brain-B
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 13 -
|
||
|
||
Brain Pakistani Brain Basit virus Lehore
|
||
Cascade 1701/1704 Falling Letters Falling Tears Autumn Leaves
|
||
Cascade(-B-C-D) 1704
|
||
Century Oregon Jan.1, 2000
|
||
Century-B
|
||
Chroma
|
||
Clone
|
||
Clone-B
|
||
Columbus Day 1280/Datacrime October 12th Friday 13th
|
||
COM virus 512 virus Friday 13th
|
||
COM-B Friday 13th-B
|
||
COM-C Friday 13th-C
|
||
Cookie virus Sesame Street
|
||
Dark Avenger
|
||
Datacrime 1280
|
||
Datacrime-B 1168
|
||
Datacrime-II 1184
|
||
dBASE virus
|
||
Den Zuk Search Venezuelan
|
||
Disk Killer Ogre
|
||
Do-Nothing (don't believe it!)
|
||
DOS-62 Vienna DOS-68 648 Austrian
|
||
DOS-68 Vienna DOS-62 648 Austrian
|
||
DOS-62 UNESCO
|
||
DOS-62-B
|
||
Falling Tears Cascade 1701/1704 Falling Letters Autumn Leaves
|
||
Falling Letters 1704 Blackjack 1704 Format
|
||
Falling Letters Cascade 1701/1704 Falling Tears Autumn Leaves
|
||
Falling Letters-Boot Ping Pong B
|
||
Fat 12 Swap Israeli Boot
|
||
FluShot4 (a corrupted version of a virus detector - use FluShot4+)
|
||
Friday 13th 1280/Datacrime Columbus Day October 12th COM
|
||
Friday 13th-B COM-B 512
|
||
Friday 13th-C COM-C
|
||
Fumble Type
|
||
Fu Manchu 2086
|
||
Ghost-Boot
|
||
Ghost-COM
|
||
Golden Gate 500 Virus
|
||
Golden Gate -B
|
||
Golden Gate-C Mazatlan
|
||
Golden Gate-D
|
||
Harddisk Brain Brain-B Brain-HD Houston virus
|
||
Holland Girl Sylvia
|
||
Houston virus Brain-B Brain-HD Harddisk Brain
|
||
Icelandic Disk-Crunching-virus Saratoga 2
|
||
Icelandic 1 Saratoga 1
|
||
Icelandic 2 System virus
|
||
INIT29
|
||
IRQ v. 41
|
||
Israeli Friday13 Jerusalem Black Box/Hole 1808/1813 PLO
|
||
Israeli Boot Swap Fat 12
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 14 -
|
||
|
||
Italian virus Bouncing Ball Vera Cruz Ping Pong Bouncing Dot
|
||
Jan.1, 2000 Century Oregon
|
||
Jerusalem Israeli Black Box/Hole 1808/1813 PLO Friday 13th
|
||
Jerusalem-B New Jerusalem
|
||
Jerusalem-C
|
||
Jerusalem-D
|
||
Jerusalem-E
|
||
Jork
|
||
Key
|
||
Lehigh
|
||
Lehigh-2
|
||
Lehore Brain Pakistani Brain Basit
|
||
Lisbon
|
||
LodeRunner Apple II GS
|
||
MacMag Peace virus
|
||
Madonna (while the nice music plays, your hard disk is being destroyed)
|
||
Mailson
|
||
Marijuana New Zealand Stoned
|
||
Mazatlan Golden Gate-C
|
||
Merritt Alameda virus Yale Peking Seoul
|
||
Mix1
|
||
Music virus Oropax virus
|
||
New Jerusalem Jerusalem-C
|
||
New Zealand Stoned Marijuana Australian
|
||
New Zealand-B Stoned-B
|
||
New Zealand-C Stoned-C
|
||
nVIR
|
||
October 12th 1280/Datacrime Columbus Day Friday 13th
|
||
Ohio
|
||
Ogre Disk Killer
|
||
Oregon Century
|
||
Oropax virus Music virus
|
||
Pakistani Brain Lehore Basit Brain
|
||
Palette Zero Bug
|
||
Payday
|
||
Peace Virus MacMag
|
||
Pearson
|
||
Peking Alameda virus Yale Merritt Seoul
|
||
Pentagon
|
||
Ping Pong Bouncing Dot Italian virus Bouncing Ball Vera Cruz
|
||
Ping Pong-B Falling Letters-Boot
|
||
PLO Jerusalem Friday 13th 1808/1813 Israeli
|
||
Russian Black Hole
|
||
Sacramento Alameda-B Yale C
|
||
Saratoga 1 Icelandic 1
|
||
Saratoga 2 Icelandic Disk-Crunching-virus
|
||
Scores
|
||
Search Den Zuk Venezuelan
|
||
Seoul Alameda virus Yale Merritt Peking
|
||
Sesame Street Cookie virus
|
||
SF virus
|
||
Shoe virus UIUC virus (see also Terse Shoe)
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 15 -
|
||
|
||
Shoe virus-B
|
||
Stoned New Zealand Marijuana Australian
|
||
Stoned-B New Zealand-B
|
||
Stoned-C New Zealand-C
|
||
SUMDOS
|
||
Sunday
|
||
SRI (destroys anti-viral programs before it damages your system)
|
||
SURIV01 April 1st
|
||
SURIV02 April 1st
|
||
SURIV03
|
||
Swap Israeli Boot Fat 12
|
||
Sylvia Holland Girl
|
||
SYS
|
||
Syslock 3551
|
||
System virus Icelandic 2
|
||
Taunt AIDS VGA2CGA
|
||
Terse Shoe (see also Shoe virus)
|
||
TP04VIR Vacsina
|
||
TP25VIR Yankee Doodle
|
||
TP33VIR Yankee Doodle
|
||
TP34VIR Yankee Doodle
|
||
TP38VIR Yankee Doodle
|
||
TP42VIR Yankee Doodle
|
||
TP44VIR Yankee Doodle
|
||
TP46VIR Yankee Doodle
|
||
Traceback 3066
|
||
Typo (boot)
|
||
Typo (COM) Fumble
|
||
UIUC virus Shoe virus
|
||
UNESCO DOS-62
|
||
Venezuelan Den Zuk Search
|
||
Vera Cruz Ping Pong Bouncing Dot Italian Virus Bouncing Ball
|
||
Vacsina TP04VIR
|
||
VGA2CGA AIDS Taunt
|
||
Vienna DOS-62 DOS-68 648 Austrian
|
||
Vienna-B
|
||
Yale Alameda virus Merritt Peking Seoul
|
||
Yale C Alameda-B Sacramento
|
||
Yankee Doodle TP25VIR
|
||
Yankee Doodle TP33VIR
|
||
Yankee Doodle TP34VIR
|
||
Yankee Doodle TP38VIR
|
||
Yankee Doodle TP42VIR
|
||
Yankee Doodle TP44VIR
|
||
Yankee Doodle TP46VIR
|
||
Zero Bug 1536
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 16 -
|
||
|
||
6.8 TABLE OF VIRUS EFFECTS (by virus name)
|
||
|
||
This information is a reformatted version of that which was made
|
||
available to the writer by the National Computer Security Association,
|
||
Suite 309, 4401-A Connecticut Ave. NW, Washington, D.C., 20008.
|
||
|
||
This list is not as complete as the list of names preceding. Since
|
||
viruses must be created and caught before they can be analyzed for the
|
||
type of information that follows, this list will never be as complete as
|
||
the list of names. In some instances, you may have been infected with a
|
||
variation of the name. You might wish to check this list for all
|
||
possible variations of a name you've found on the list of synonyms.
|
||
|
||
Explanation of codes used under "What it does", and analysis of frequency
|
||
of occurrence of each effect:
|
||
|
||
EFFECT # OCCURRENCES %
|
||
------ - ----------- -
|
||
1. Virus uses self-encryption 13 12
|
||
2. Virus remains resident 83 74
|
||
3. Infects COMMAND.COM 8 7
|
||
4. Infects .COM files 62 55
|
||
5. Infects .EXE files 41 37
|
||
6. Infects .OVL files 15 13
|
||
7. Infects floppy disk boot sector 36 32
|
||
8. Infects hard disk boot sector 14 13
|
||
9. Infects partition table 1 1
|
||
10. Corrupts or overwrites boot sector 31 28
|
||
11. Affects system run-time operation 53 47
|
||
12. Corrupts program or overlay files 57 51
|
||
13. Corrupts data files 4 4
|
||
14. Formats or erases all/part of the disk 17 15
|
||
15. Corrupts file linkage (FAT) 9 8
|
||
16. Overwrites program 4 4
|
||
17. Mac virus (as opposed to PC virus) 2 2
|
||
|
||
|
||
Increase in Disinfector
|
||
VIRUS NAME Prog'm size that works What it does
|
||
---------- ----------- ----------- ------------
|
||
|
||
1168/Datacrime B 1168 SCAN/D 1, 4, 12, 14
|
||
1184/Datacrime 2 1184 1, 4, 5, 12, 14
|
||
123nhalf 3907 2, 5, 11, 13
|
||
1280/Datacrime 1280 SCAN/D 1, 4, 12, 14
|
||
1514/Datacrime II 1514 SCAN/D 1, 4, 5, 12, 14
|
||
1536/Zero Bug 1536 SCAN/D 2, 4, 11, 12
|
||
1701/Cascade 1701 M-1704 1, 2, 4, 11, 12
|
||
1704/Format 1704 M-1704 1, 2, 4, 11, 12, 14
|
||
1704/Cascade 1704 M-1704 1, 2, 4, 11, 12
|
||
1704/Cascade-B 1704 M-1704 1, 2, 4, 11, 12
|
||
1704/Cascade-C 1704 1, 2, 4, 11, 12
|
||
1704/Cascade-D 1704 1, 2, 4, 11, 12
|
||
2930 2930 SCAN/D 2, 4, 5, 12
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 17 -
|
||
|
||
3066/Traceback 3066 M-3066 2, 4, 5, 12
|
||
3551/Syslock 3551 SCAN/D 1, 4, 5, 12, 13
|
||
3555 3555 1, 3, 4
|
||
405 SCAN/D 4, 16
|
||
AIDS SCAN/D 4, 16
|
||
AIDS Info Disk 0 AIDSOUT 11
|
||
Alabama 1560 SCAN/D 2, 5, 11, 12, 15
|
||
Alameda-B 2, 7, 10
|
||
Alameda-C 2, 7, 10
|
||
Alameda/Yale MDISK 2, 7, 10
|
||
Amstrad 847 SCAN/D 4, 12
|
||
April 1st 2, 4, 11
|
||
April 1st-B 2, 5, 11
|
||
Ashar MDISK 2, 7, 10
|
||
Black Hole 1808 2, 4, 5, 6, 11, 12, 15
|
||
Brain-B 2, 7, 8, 10
|
||
Brain-C 2, 7, 8, 10
|
||
Century 2, 4, 5, 6, 11, 12, 14, 15
|
||
Century-B 2, 4, 5, 6, 11, 12, 14, 15
|
||
Clone-B 2, 7, 10, 15
|
||
Clone virus 2, 7, 8, 10
|
||
dBASE 1864 SCAN/D 2, 4, 11, 12, 13
|
||
DOS-62-B 3, 4, 11
|
||
DOS-62-UNESCO 650 3, 4, 11
|
||
Dark Avenger 1800 M-DAV 2, 3, 4, 5, 6, 11, 12, 15
|
||
Datacrime II-B 1917 SCAN/D 1, 3, 4, 5, 12, 14
|
||
Disk Killer MDISK 2, 7, 8, 10, 11, 12, 13, 14
|
||
Do-Nothing 608 SCAN/D 4, 12
|
||
Fri 13th COM 512 SCAN/D 4, 12
|
||
Fri 13th COM-B 512 4, 12
|
||
Fri 13th COM-C 512 4, 12
|
||
Fu Manchu 2086 SCAN/D 2, 4, 5, 6, 11, 12
|
||
Ghost-Boot ver. MDISK 2, 7, 8, 10, 11
|
||
Ghost-COM ver. 2351 SCAN/D 4, 10, 12
|
||
Golden Gate 2, 7, 10, 14
|
||
Golden Gate-B 2, 7, 10, 14
|
||
Golden Gate-C 2, 7, 10, 14
|
||
Golden Gate-D 2, 7, 10, 14
|
||
IRQ v. 41 4, 5, 11
|
||
Icelandic I 642 SCAN/D 2, 5, 11, 12
|
||
Icelandic II 661 SCAN/D 2, 5, 11, 12
|
||
Italian/Ping Pong MDISK 2, 7, 10, 11
|
||
Italian-B MDISK 2, 7, 8, 10, 11
|
||
Jerusalem 1808 SCAN/D/A 2, 4, 5, 6, 11, 12
|
||
Jerusalem-B 1808 M-JERUSLM 2, 4, 5, 6, 11, 12
|
||
Jerusalem-C 1808 2, 4, 5, 6, 11, 12
|
||
Jerusalem-D 1808 2, 4, 5, 6, 11, 12
|
||
Jerusalem-E 1808 2, 4, 5, 6, 11, 12, 15
|
||
Jork 2, 7, 10
|
||
Lehigh SCAN/D 2, 3, 12, 14, 16
|
||
Lehigh-2 2, 3, 12, 14, 15, 16
|
||
Lisbon 648 SCAN/D 4, 12
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 18 -
|
||
|
||
MIX1 1618 SCAN/D 2, 5, 11, 12
|
||
New Jerusalem 1808 M-JERUSLM 2, 4, 5, 6, 11, 12
|
||
New Zealand MD 7
|
||
New Zealand-B 7, 8
|
||
New Zealand-C 7, 8
|
||
nVIR 11, 17
|
||
Ohio MDISK 2, 7, 10
|
||
Oropax 2, 4
|
||
Pakistani Brain MDISK 2, 7, 10
|
||
Palette/Zero Bug 1536 2, 3, 4,
|
||
Payday 1808 M-JERUSLM 2, 4, 5, 6, 12
|
||
Pentagon MDISK 7, 10
|
||
SF Virus 2, 7, 11, 14
|
||
SRI 1808 2, 4, 5, 6, 11, 12
|
||
SURIV01 897 SCAN/D 2, 4, 11, 12
|
||
SURIV02 1488 SCAN/D 2, 5, 11, 12
|
||
SURIV03 SCAN/D 2, 4, 5, 6, 11, 12
|
||
SYS 2, 7, 8, 11, 12
|
||
SYS-B 2, 7, 8, 11, 12
|
||
SYS-C 2, 7, 8, 11, 12
|
||
Saratoga 632 SCAN/D 2, 5, 11, 12
|
||
Saratoga-2 2, 5, 11, 12
|
||
Scores 11, 17
|
||
Search HD 2, 7, 8, 10, 11
|
||
Search-B 2, 7, 10, 11
|
||
Search/Den Zuk MDISK 2, 7, 10, 11
|
||
Shoe virus 2, 7, 8, 10
|
||
Shoe virus-B 2, 7, 10
|
||
Stoned/Marijuana MDISK/P 2, 7, 9, 10, 11, 15
|
||
SumDOS 1500 4, 5, 14
|
||
Sunday 1636 SCAN/D 2, 4, 5, 6, 11, 12
|
||
Swap/Israeli Boot MDISK 2, 7, 10
|
||
Sylvia/Holland 1332 SCAN/D 2, 4, 12
|
||
Terse Shoe virus 2, 7, 10
|
||
Typo (Boot) MDISK 2, 7, 8, 10, 11
|
||
Typo/Fumble (COM) 867 SCAN/D 2, 4, 11, 12
|
||
Vacsina/TP04VIR 2, 4, 5
|
||
Vienna-B 648 SCAN/D 2, 4, 5, 12
|
||
Vienna/648 648 M-VIENNA 4, 12
|
||
Yankee Doodle 2855 SCAN/D 2, 4, 5, 11, 12
|
||
Yankee Doodle/TP25VIR 2, 4, 5
|
||
Yankee Doodle/TP33VIR 2, 4, 5
|
||
Yankee Doodle/TP34VIR 2, 4, 5
|
||
Yankee Doodle/TP38VIR 2, 4, 5
|
||
Yankee Doodle/TP42VIR 2, 4, 5
|
||
Yankee Doodle/TP44VIR 2, 4, 5
|
||
Yankee Doodle/TP46VIR 2, 4, 5
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 19 -
|
||
|
||
6.9 VIRUS DETECTOR AND ANTIDOTE SOFTWARE
|
||
|
||
*** None offer complete protection ***
|
||
|
||
Some do NOT test for boot sector viruses, modification of the command
|
||
interpreter, branching into the BIOS, etc., unconventional things that
|
||
nasty viruses are known to do. This is not a comprehensive list, but
|
||
you'll have an idea of what's available, either commercially or through
|
||
public domain. Look for a product that will detect as many of the
|
||
effects identified in the previous section as possible. Warning: some
|
||
highly publicized virus detectors only search for ONE (1) virus! Others
|
||
are more sophisticated, and may even act as a disinfector as well as a
|
||
detector.
|
||
|
||
|
||
Old virus symptoms vs file changes
|
||
Antidote
|
||
Antigen
|
||
|
||
Bombsqad
|
||
Canary
|
||
Cylene-4
|
||
C-4
|
||
Disk Defender * recommended (add-on board - write-protects hard disk)
|
||
Disk watcher
|
||
Dr. Panda Utilities
|
||
IBM - COMPare in DOS
|
||
Mace vaccine
|
||
Magic Bullets
|
||
Syringe
|
||
Sentry * recommended for systems booted regularly
|
||
Vaccine
|
||
Viraid
|
||
Virus-Pro * recommended for large corporate environments
|
||
Shareware: Novirus
|
||
Flushot4+
|
||
Virusck
|
||
Viruscan
|
||
|
||
Plus what's shown on preceding pages as a "Disinfector that works". I
|
||
also have a list of over 100 shareware products that do everything from
|
||
detect and/or disinfect to write-protecting the hard drive and requiring
|
||
password access .... but my fingers are getting tired from typing at this
|
||
point, and there are more important things to cover - after all, if
|
||
you're careful, you won't need a list of detectors/disinfectors.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 20 -
|
||
|
||
6.10 TROJAN HORSES
|
||
|
||
While a "virus" is something hidden within another program that is
|
||
waiting to make your system really sick, and a "worm" may be something
|
||
that lives on its own and usually transmits through networked computers,
|
||
a "Trojan Horse" is a little of both, so I've included it with this virus
|
||
section if only to warn you of its existence. It lives on its own as a
|
||
program, and will bring you down like Helen of Troy's soldiers. "I
|
||
wouldn't copy something like that," you say. Well, like Helen's horse,
|
||
it comes disguised. It will purport to do something really neat, like
|
||
compress files (so you have more disk space available), sort your
|
||
directories (so you can find things more easily), or play chess or
|
||
another game with you. In actuality, it's really just waiting to do the
|
||
things that viruses do - trash your files, scramble your boot sector, fry
|
||
your FAT, or erase your hard disk. It doesn't usually do anything it
|
||
promises to do.
|
||
|
||
The following are just a few examples of the known Trojan Horses, most
|
||
of which come from bulletin boards. Please don't misunderstand me, most
|
||
BB operators are honest people who are trying to help the computer
|
||
industry as a whole, but they can't be held responsible for the people
|
||
who might dial into their BB and leave a disaster waiting until the next
|
||
caller(s).
|
||
|
||
|
||
SCRNSAVE.COM: This is supposed to blank your screen after x seconds of
|
||
inactivity, thus preventing image burn-in or apparently
|
||
offering a sense of security; say goodbye to your files
|
||
while it erases your harddisk.
|
||
|
||
TSRMAP: For the 'sophisticated' user who uses Terminate and Stay
|
||
Resident programs, it's sometimes handy to have a map of
|
||
where these programs are loaded in memory, and be able to
|
||
delete some if you're short of memory; hopefully this
|
||
same 'sophisticated' user has a copy of track 0, because
|
||
his was just sent to heaven ..... or elsewhere.
|
||
|
||
DOS-HELP: Sounds great, doesn't it? This TSR program is supposed to
|
||
give on-line help on DOS commands. Your hard disk was
|
||
just formatted.
|
||
|
||
ULTIMATE.EXE: This is supposed to be a DOS shell (if you've used
|
||
Directory Scanner or some other software that allows you
|
||
to move around directories and load programs easily, or
|
||
even a menu system, then you know what a DOS shell is).
|
||
While the "Loading..." message shows on your screen, the
|
||
FAT (file allocation table) of your hard disk went to the
|
||
trash bin.
|
||
|
||
BARDTALE.ZIP This purports to be a commercial game from Electronic Arts
|
||
(BARDTALE I) Someone reverse engineered this program, and
|
||
wrote in a routine to format your hard disk upon
|
||
invocation.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 21 -
|
||
|
||
COMPRESS.ARC This is dated April 1 1987, is executed from a file named
|
||
RUN-ME.BAT, and is advertised as "shareware from Borland"
|
||
(Borland is a highly reputable company). It will not
|
||
compress your files, but it will very competently destroy
|
||
your FAT table.
|
||
|
||
|
||
DANCERS.BAS You'll actually see some animated dancers in colour -
|
||
while your FAT is being tromped on.
|
||
|
||
DEFENDER.ARC Think you're going to get a copy of Atari's DEFENDER for
|
||
nothing, huh? There's still no such thing as a free
|
||
lunch, and this one will be particularly expensive: it
|
||
not only formats your hard disk, but it writes itself to
|
||
your ROM BIOS - the chip that holds the Basic Input Output
|
||
System for your machine. Get your wallet out.
|
||
|
||
SIDEWAYS.COM The good "SIDEWAYS.EXE" is about 30Kb, while this version
|
||
is about 3Kb. The really big difference, though, is what
|
||
happens to your hard drive - it's spun off into oblivion.
|
||
|
||
|
||
These are only a few of the 70 or so Trojans I have listed at work, but
|
||
I'm sure you've got the idea. These programs (a) stand alone, (b) often
|
||
claim to do something useful, (c) may be hacked versions of good
|
||
software, (d) may be named the same as good software, (e) may send you
|
||
back to using a quill pen.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 22 -
|
||
|
||
7. PC RULES OF THUMB (Additional to Basic Rules of Thumb)
|
||
|
||
Run virus check BEFORE backup
|
||
|
||
Boot floppy systems from known, protected disks only
|
||
|
||
Never work with masters - first make copies on a trusted machine
|
||
|
||
Store data on floppy:
|
||
set path in autoexec.bat, but load from A: to
|
||
ensure data goes to floppy
|
||
|
||
Save your data periodically while working
|
||
|
||
Use write protect tabs
|
||
|
||
Use write protect software on hard disk / backup track 0
|
||
|
||
Never boot HD systems from floppies (unless known and
|
||
protected)
|
||
|
||
New/repaired hard disk? - run a virus detector
|
||
|
||
Use protection package (practice safe hex)
|
||
|
||
Avoid shareware / BB demos
|
||
if you use a BB, set path to A: beforehand,
|
||
download only to A:, poweroff immediately after,
|
||
then powerup and do a virus scan on the floppy;
|
||
always scan shareware
|
||
|
||
Know the source of your software
|
||
|
||
Don't use illegal copies
|
||
|
||
If your data is truly confidential, don't depend on
|
||
DELETE - you must use, e.g., Wipefile
|
||
|
||
Autopark software
|
||
|
||
Hardcards
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 23 -
|
||
|
||
6. A FEW EASY TRICKS FOR PC SECURITY
|
||
|
||
|
||
1. Set Read only attributes on all files ending with .COM, .EXE, .SYS,
|
||
. OVL, .BIN, .BAT
|
||
|
||
e.g.: ATTRIB +R *.SYS
|
||
|
||
|
||
|
||
2. Use an undocumented trick in DOS of naming your data files ending
|
||
with an ASCII blank or NUL character (ASCII 32 or 255): ***
|
||
|
||
e.g.: COPY A:OLDFILE.TXT NEWFILECHR$(255).TXT
|
||
or REN A:MYFILE.DAT MYFILECHR$(32).DAT
|
||
|
||
*** Newer versions of DOS will give the ASCII blank or null by
|
||
holding the [Alt] key and striking the numeric keypad numbers;
|
||
e.g. COPY A:OLDFILE.TXT NEWFILE[Alt]255
|
||
|
||
|
||
|
||
3. Prevent inadvertent formatting of the hard disk:
|
||
|
||
Rename FORMAT.EXE to (e.g.) DANGER.EXE
|
||
Write a 1-line batch file called FORMAT.BAT:
|
||
DANGER A: %1 %2 %3 %4 %5 %6
|
||
|
||
|
||
4. Have a batch program as a shutdown routine, to run:
|
||
|
||
1. Virus Check
|
||
2. Copy Track 0
|
||
3. Back up your data files
|
||
4. Park the heads
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 24 -
|
||
|
||
9. SO YOU'RE INFECTED
|
||
|
||
|
||
Terminate all connections with other computers
|
||
|
||
Record your last activities
|
||
|
||
Determine the nature and extent of the damage
|
||
|
||
Notify other users
|
||
|
||
Contact the source of the carrier software
|
||
|
||
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
|
||
|
||
|
||
Back up data files to new diskettes
|
||
|
||
Erase infected disk (using high or low level format -
|
||
low level is preferred to re-write track 0)
|
||
|
||
Check master disks with detection program(s)
|
||
|
||
Restore system files
|
||
|
||
Restore data files
|
||
|
||
Run detection program(s) again
|
||
|
||
Be careful in future - think like a thief!
|
||
------------------
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 25 -
|
||
|
||
10. SUMMARY: WHAT CAN YOU DO?
|
||
|
||
There are many aspects to computer security, none of which are totally
|
||
within your control, but all of which are reasonably within your control.
|
||
One of the major methods of getting control is to establish an
|
||
enforceable security policy AND a disaster recovery plan. However, it's
|
||
almost impossible to establish a plan unless you first know what the
|
||
risks are.
|
||
|
||
WHEN YOU GO BACK TO YOUR OFFICE
|
||
|
||
Try putting some staff into two teams: "hackers" and "police" (or call
|
||
them Blue Jays and Cardinals if you find that offensive). The role of
|
||
the hackers is to try to dream up all the things they could get from or
|
||
do to the company (or to a department) by breaking computer security.
|
||
The role of the police is to respond with defenses. Then switch roles.
|
||
List all the ideas, no matter how "far out" they seem, then use this for
|
||
the basis of risk analysis and disaster recovery planning. The only rule
|
||
to this game is that no idea is initially rejected.
|
||
|
||
Now that you have some idea of the value of your data and the risks it is
|
||
under, you can begin to work on a "Computer Security Policy" and a
|
||
"Disaster Recovery Plan." While many suggestions have been made on the
|
||
previous pages, recognize that not all risks/solutions apply to all
|
||
organizations: you have to make some judgement calls based on your
|
||
assessment of the risk. The judgement is based on how much loss you can
|
||
comfortably sustain, yet remain in business. The level of security
|
||
protection you require may not always be the same. It may vary with the
|
||
value of the hardware, software or data under consideration; the
|
||
security level, therefore, might be stated as "minimal," "discretionary,"
|
||
"mandatory," or "verified." The point is, as long as it's been
|
||
considered, you're closer to having a good security system than if you
|
||
have no policy or a policy that's based on guesswork.
|
||
|
||
You may find, after working on this for a while, that you may wish to
|
||
develop a separate policy for the selection or development, change,
|
||
testing and implementation of software. This might be stated as simply
|
||
as, "No system shall be acquired, developed, changed or implemented
|
||
without the prior approval of the Systems Steering Group." This might
|
||
also go on to cover documentation; e.g., "Documentation must be complete
|
||
for all systems prior to implementation, and must include sections on
|
||
files used, access controls, security considerations and controls
|
||
(etc.)."
|
||
|
||
Some further points for consideration are included in the next section.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 26 -
|
||
|
||
11. COMPUTER SECURITY POLICY: POINTS FOR CONSIDERATION
|
||
|
||
Any policy on computer security must be based on the premise that
|
||
information is a valuable asset of the company, just like its premises,
|
||
equipment, raw materials, inventory and so on. More than one company has
|
||
gone under because they lost their accounts receivable data in a fire,
|
||
flood, or from a simple hard disk failure. The value of your data should
|
||
be subjected to a risk analysis, and all identifiable risks assessed. It
|
||
is not until you identify the risks that you can plan for a disaster
|
||
recovery.
|
||
|
||
Your policy might include some of the many things addressed previously in
|
||
this paper: e.g., storing data only on removable media (diskettes or
|
||
tapes), limiting access to bulletin boards, establishing password
|
||
controls, rules on physical security, use of immunization software, etc.
|
||
There are, however, some other specific points not previously discussed:
|
||
|
||
RESPONSIBILITY
|
||
Recognize that security is a management issue, not a technological
|
||
issue, and that setting policy is the responsibility of senior
|
||
management. They must be 'on board' and understand why a security policy
|
||
is needed to make it sensible and effective, and they must give overt
|
||
support.
|
||
|
||
Someone should be in charge of computer and network security. Without
|
||
someone in charge, important security tasks may not get done. The duties
|
||
of the security manager would include responsibility for limiting access
|
||
to the network, securing the information that passes over it, overseeing
|
||
password systems, and installing security packages that protect computers
|
||
from illegal tampering once a user is on the network. Other duties might
|
||
include analyzing the network for security weaknesses and helping users
|
||
understand the security strengths and weaknesses of the network.
|
||
|
||
The amount of time required of the system security specialist may depend
|
||
on the size of the organization, and on the number and complexity of the
|
||
systems in use or planned.
|
||
|
||
Having one person in charge is probably the ideal security arrangement.
|
||
The security specialist can become aware of all of the issues affecting
|
||
computer/network security, can schedule and establish priority for
|
||
actions, and can ensure that the actions are taken.
|
||
|
||
This position in the organization requires some authority and autonomy.
|
||
For instance, security is compromised if the boss shares his/her
|
||
password. The security specialist needs to be able to change the boss's
|
||
password if this happens, and gently but firmly discuss the problems
|
||
which could result.
|
||
|
||
|
||
In many organizations, putting two or more people in charge of something
|
||
diffuses responsibility. Each can think that some security concern was
|
||
the responsibility of the other. If two individuals are charged with
|
||
network security, be certain that they work well together, communicate
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 27 -
|
||
|
||
well, and will each put in their fair share of the analysis and work that
|
||
is required for security.
|
||
|
||
In some organizations, a "communications manager" is responsible for
|
||
limiting access to the network (with dialback modems and encryption
|
||
devices), while the network manager maintains password systems and
|
||
installs security software.
|
||
|
||
If someone is in charge of network security and you don't know about it,
|
||
then they haven't been very obvious about it. They need not be. But if
|
||
it is evident to you that security is lacking, then perhaps the issue of
|
||
responsibility should be examined (or re-examined).
|
||
|
||
|
||
BACKUPS
|
||
Those who are most zealous about backups are those who've been affected
|
||
in the past by a loss of data. If backups are performed every day, your
|
||
computer or network is probably in good shape when the hard disk or file
|
||
server goes to heaven. You will want to verify that this is the case,
|
||
since most organizations (and individuals) put this off... and off...
|
||
until it's too late.
|
||
|
||
Backing a system up once a week is not enough, unless the system is
|
||
rarely used. If your last backup was a week ago, and your hard disk or
|
||
the hard disk in the file server crashes, all users of the network have
|
||
lost one week's work.
|
||
|
||
This cost is enormous. If you have 10 users who have lost 30 hours of
|
||
work each, if each user is paid $20/hour, and overhead is 100%, then you
|
||
have just lost 10 x 30 x 20 x 2 = $12,000. If you assume that backup
|
||
takes one $20 hour with a tape drive, you could back the system up 600
|
||
times for $12,000. That's nearly three years, if backups are done five
|
||
times a week. Many hard disks will not run continuously for three years.
|
||
Even if you're a 'stand alone' computer user, your time is valuable. You
|
||
might consider a policy that, if recovery covers a period of more than
|
||
'x' days, it must be done on the employee's own time, and all deadlines
|
||
must be met - tough, but it get's the point across!
|
||
|
||
Irregular backups are a sign that backup is not taken as seriously as it
|
||
should be. It is probably wisest to do the arithmetic, comparing the
|
||
costs of backup with the costs of losing work for multiple users. The
|
||
cost comparison in the commentary on the second answer doesn't even
|
||
consider the possibility of losing irreplaceable files, such as those
|
||
containing new accounts receivable entries or new prospects.
|
||
|
||
Since file backup is a "private" activity, not knowing how often it
|
||
occurs does not mean that it does not occur. But if you have a security
|
||
concern, you should find out what the correct answer is. After all, if
|
||
you use the network, and it is not backed up frequently, it is your work
|
||
that is lost when the hard disk in the server crashes.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 28 -
|
||
|
||
BEWARE: backing up is NOT enough! You MUST periodically run your
|
||
recovery procedure .... how else will you know it will work when you need
|
||
it most?
|
||
|
||
|
||
PURCHASING
|
||
The policy should state the controls in place for purchase of both
|
||
hardware and software, and it should be consistent and centralized.
|
||
Unless you've seen what some software can do to destroy security, or how
|
||
difficult it is to interconnect different equipment, this might seem to
|
||
destroy some autonomous activities in your organization. Autonomy be
|
||
darned, it's the company that's paying the bill.
|
||
|
||
|
||
MAINTENANCE AGREEMENTS
|
||
All warranty registrations must be mailed to the manufacturer, and
|
||
records kept of purchase dates, expiry dates and repairs made under the
|
||
warranty. Keeping accurate records has substantiated the complete
|
||
replacement of more than one machine.
|
||
|
||
|
||
SOFTWARE LOADING
|
||
The checking, copying and loading of software should be the
|
||
responsibility of one person or department. The 'penalty' for loading
|
||
illegal/unauthorized software can range from a note in the personnel file
|
||
to dismissal, depending on the organization. The opposite, copying the
|
||
organization's software for loading in another location, should also be
|
||
covered in the policy, because the company (as the registered owner)
|
||
could be party to a lawsuit without the ability to plead ignorance.
|
||
|
||
|
||
|
||
|
||
|
||
EMPLOYMENT TERMINATION
|
||
In several organizations, when a person submits their resignation, their
|
||
access to the computer system is immediately withdrawn. This, of course,
|
||
requires a close liaison with the personnel department in large
|
||
organizations. Many of these companies feel it's worth the salary cost
|
||
to have the person leave the premises immediately (escorted), and simply
|
||
pay out their notice period. If your company adopts such a policy, it
|
||
should be made very clear that it is not an indication of trust in the
|
||
person, but simply a means to reduce risk to the valuable resources of
|
||
hardware, software and data. It must be administered consistently and
|
||
equitably to avoid problems. There are problems with such a policy,
|
||
not the least of which could be someone who gives a very lengthy notice
|
||
period simply because they're aware of the policy - but you could
|
||
transfer them to a clerical job for the interim (like the mail room) or
|
||
to maintenance staff (washroom detail).
|
||
|
||
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
- 29 -
|
||
|
||
12. TO RUN SCAN (Virus detection software included on this diskette)
|
||
|
||
SCAN looks for 42 viruses in software files, but not in data files. I
|
||
know it works on Jerusalem-B because I used SCAN to detect that virus on
|
||
a machine at work. This is NOT the latest version of SCAN, but then
|
||
again, you're not likely to have the latest viruses (I hope).
|
||
|
||
If you want to print the documentation, type: COPY A:SCAN.DOC PRN
|
||
If you want to run SCAN, just type: A:SCAN [drive identifier]
|
||
e.g., A:SCAN C:
|
||
|
||
|
||
An article from the Washington Post, January 14, 1990, on Computer
|
||
Viruses was added to the diskette after this paper was written.
|
||
|
||
To read this article, key TYPE A:ARTICLE|MORE
|
||
To print the article, key COPY A:ARTICLE PRN
|
||
|
||
|
||
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||
|
||
|
||
If you have found this presentation useful, either by attending or by
|
||
reading or using the information on this diskette, then I am rewarded.
|
||
If you found it useful, please feel free to copy this diskette or its
|
||
contents and share it with others - I would ask that you don't change
|
||
anything, though. (It was virus free at the time I made the original
|
||
diskette - but if you trust that statement, you might just have made your
|
||
first mistake.)
|
||
|
||
If you'd like to make suggestions that would improve the information on
|
||
this diskette, I would be very happy to hear from you. I'd also like to
|
||
hear from you if you wish to discuss security issues, get a virus
|
||
infection or hit by a Trojan Horse, or even just to comment on the
|
||
contents of this paper. My address and phone number are on the first
|
||
page of this document.
|
||
|
||
If you would like to join the National Computer Security Association, a
|
||
'form' for application is on the next page. They provide benefits such
|
||
as a Virus Self-Defense Kit that's more sophisticated than the software
|
||
on this diskette, newsletters, a virus-free bulletin board with hundreds
|
||
of security-related programs, discounts on software, books and
|
||
conferences, and advice if you run into trouble.
|
||
|
||
Happy (and safe) computing!
|
||
|
||
|
||
E. A. (Liz) Bedwell
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
National Computer Association
|
||
Suite 309
|
||
4401-A Connecticut Ave. NW
|
||
Washington, DC
|
||
USA 20008 Phone: (202) 364-8252
|
||
|
||
|
||
|
||
|
||
[ ] I wish to join NCSA. Cheque enclosed for $45.00 (US funds)
|
||
|
||
[ ] I wish to join NCSA. Please bill me for $45.00 (US funds)
|
||
|
||
|
||
Name: _____________________________________________________
|
||
|
||
Organization: _____________________________________________________
|
||
|
||
Address: _____________________________________________________
|
||
|
||
_____________________________________________________
|
||
|
||
City, Prov.: ____________________________ Postal Code ____________
|
||
|
||
Phone (with area code): ___________________________________________
|
||
|
||
|
||
Title or Position, or interest in computer security:
|
||
|
||
_____________________________________________________
|
||
|
||
_____________________________________________________
|
||
|
||
|