77 lines
3.7 KiB
Plaintext
77 lines
3.7 KiB
Plaintext
ÄÄÄ TG SysOp's Protect Your Selves ÄÄÄ
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ÄÄÄ From Baddies ÄÄÄ
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ÄÄÄ by Man Against The Mob ÄÄÄ
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ÄÄÄ The Pie BBS 516-689-5413 ÄÄÄ
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Hey you, don't be silly, put a rubber on your willy!
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As telegard is a popular BBS software package, and is widely available
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to the general public, it becomes easy for hackers to crash your system.
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I have written this file to help protect your self from these people.
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Included are tree ways to protect your self. I also recommend you use a
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shuttle logon menu to provide more security. With one new users do not have
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access to the board on their first call.
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1) The PKZIP back door - Users who wish to crash your board can call your
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board, upload a zip file containing a trojan named PKZIP.EXE. they can use
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the archive file menus to unzip the PKZIP.EXE trojan file to your temp file
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directory. They can then run the file by selecting Add to Archive which will
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then attempt to run PKZIP.EXE to zip up the file. But if a PKZIP.EXE file is
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in the temporary directory, it will run that one instead of the true PKZIP
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program. To protect your self from this, press //\\*P from any menu, select
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option 'F' and then press 'A'. Modify the PkZip Archive entry to include the
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path of the true PKZIP.EXE and PKUNZIP.EXE files.
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ie. use 3) C:\ZIP\PKZIP.EXE -aex @F @I
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instead of 3) PKZIP.EXE -aex @F @I.
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2) The Logoff.Bat back door - A user can ZModem batch upload a file called
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Logoff.Bat to your Telegard directory using various commands in DSZ. I won't
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go into them because this is a file to prevent it, not tell how to do it.
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This uploading is mostly blindly giving a path name hoping it is in the
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C:\BBS directory or whatever path they try. They they are trying to do is
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get ZModem batch to upload a file called Logoff.Bat to the main BBS
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directory.
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What Logoff.Bat does is each time a user logs off, telegard will run
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Logoff.Bat if it exists. It is mostly used in BBS's which use front doors to
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help run echo's between different bulletin boards, such as D'Bridge. If the
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Logoff.Bat file contains a nasty such as WIPEDISK C: or something to that
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extent, bad things will happen. You can stop that by adding the word
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'Restrict' to the end of your Zmodem upload strings.
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ie. use dsz port %P speed %B rz %F Restrict
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instead of dsz port %P speed %B rz %F.
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Here is DSZ's documentation or Restrict:
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restrict Restrict pathnames to the current disk and directory tree, and
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disallow overwriting of existing files. When DSZ is restricted,
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it will refuse to transfer files containing the string autoexec.bat
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and command.com in upper or lower case. This provides some defense
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from malicious uploaded files.
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3) Scan all uploaded files for viruses and trojans before you run them.
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A method used by some Telegard's I have seen is to replace the Integrity
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check line with a batch file which tests for initial integrity, then it
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Unzips the file to a temporary directory, run the SCAN program and exit with
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a good exit code telling TG it is alright. This is a sample batch file for
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doing that: (You will have to look up the correct exit codes for your SCAN
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and PkZip programs)
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ECHO OFF
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C:\ZIP\PKUNZIP -t %1
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IF ERRORLEVEL = 1 Goto Badfile
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MD\0UR12.$$$
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C:\ZIP\PKUNZIP %1 C:\0UR12.$$$
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CD\0UR12.$$$
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C:\ZIP\SCAN *.*
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echo y|del *.*
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:Badfile
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exit
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And have in Telegard 0 (or whatever) as a good exit code. (And make sure
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SCAN's exit code is not 0 (or whatever) for bad files.
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For more help with Telegard Call <\ The Pie BBS /> 516-689-5413.
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This text file was written by Man Against The Mob.
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This text file has been brought to you by MHEB Enterprises.
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ile has been brought to you by MHEB Enterprises.
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