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- VIRUS-L Digest Wednesday, 11 Jan 1989 Volume 2 : Issue 11
-
- Today's Topics:
- Re: proprietary vs pd software
- boot sequence (PC)
- VIRUS ALERT: possible virus... keywords: CBUG, WEIRD (PC)
-
- ---------------------------------------------------------------------------
-
- [Ed. While trying to move the editing of VIRUS-L over to a different
- machine today, I had a fight with the LISTSERV - it was converting my
- address to uppercase, and Xenix wasn't delivering the mail to me.
- It's possible that, during the scuffle, one or two messages to the
- list were lost, and/or sent back to their author(s). If this happened
- to you, please resubmit your message, and I apologize.]
-
- Date: Wed, 11 Jan 89 13:51:35 EST
- From: Neil Goldman <NG44SPEL@MIAMIU.BITNET>
- Subject: Re: proprietary vs pd software
-
- Stan Horwitz writes that Fred Cohen has determined that proprietary
- software is a more common source of viruses than public domain (and
- shareware?) software is. This seems contrary to all the discussion I
- have read and participated in on this list as well as in published
- reports (for whatever they are worth).
-
- I am very interested in how Dr. Cohen has determined this.
-
- Comment?
-
- Neil A. Goldman NG44SPEL@MIAMIU.BITNET
-
- Replies, Concerns, Disagreements, and Flames expected.
- Mastercard, Visa, and American Express not accepted.
- Acknowledge-To: <NG44SPEL@MIAMIU>
-
- ------------------------------
-
- Date: 11 January 89, 20:00:17 +0100 (MEZ)
- From: Otto Stolz +49 7531 88 2645 RZOTTO at DKNKURZ1
- Subject: boot sequence (PC)
-
- > When a user presses ctl-alt-del, the keyboard code in BIOS [...]
- > redirects interrupt vectors to their default values, then boots. A
- > worm sitting in memory (not a _virus_) would have to duplicate all the
- > machine-specific stuff for various possible machines
-
- What if the virus (why not?), or worm, simply hooks Int 9?
-
- Then it could fake the warm boot by resetting the interrupt vectors
- in a non-standard way that allowed itself to survive in memory and then
- jumping to the booting code. The machine-specific stuff would only be
- the default values of the interrupt vectors (may be, even they are rather
- standard, or can be derived from the memory contents -- I don't know).
-
- Or it could infect the disk/diskette to be booted from, and then rely
- on BIOS to be installed again; the machine specific stuff would be nil,
- and if it was a boot-sector virus, all required subroutines would already
- be part of it.
-
- Just a thought...
-
- O, I just remember some expert told me that the Yale virus did redefine
- Ctrl-alt-Sequences. Hence I guess, my thought is not so far off from
- what virus-inventors might consider. So, be prepared!
-
- Conclusion: Never, ever, warm-boot an infected computer.
-
- Best wishes
- Otto
-
- ------------------------------
-
- Date: Wed, 11 Jan 89 16:04:00 EST
- Sender: Virus Alert List <VALERT-L@IBM1.CC.Lehigh.Edu>
- From: Michael Brown <BROWN@CMR001.BITNET>
- Subject: VIRUS ALERT: possible virus... keywords: CBUG, WEIRD (PC)
-
- *Something a bit strange has appeared in one of our IBM PC labs.*
-
- One of our AT clones has a file called C:\CBUG.COM. Running CBUG.COM
- has the following effect: The first time the Y key is pressed, it
- prints the message "YOUR COMPUTER IS NOW INFECTED WITH SOME WEIRD VIRUSES",
- and it hangs the system. A warm boot will restore the system to normal.
-
- I looked at the file with PCTOOLS. It is a normal .COM file with a
- length of 149 bytes. The message is clearly embedded in the beginning of
- the file. The rest of the file contains a block of 00h then a irregular
- pattern of 00h 0Fh and FFh. The file is dated 1/01/80 (which is unusual,
- because that machine has a clock, and usually get the date right) and
- the machine is running PCDOS 3.3.
-
- I checked the disk for other occurrences of the message, but it seems
- to only be there once.
-
- If I cold start the system:
- - run CBUG once, and type a Y, I get the message and the system hangs
- - run CBUG twice, and type a Y, I get the message and the system hangs
- - either time the system will warm boot
- - run CBUG three times, and type a Y, I get the message, the next time
- I type a Y it displays the message again and again until the fourth time
- the Y key is typed, then the system hangs and I cannot do a warm boot.
- - - something similar happens if I run CBUG four times.
- - - If I run CBUG five times, the number of time before the system hangs
- is irregular, but it always displays the message.
-
- Enough said.
-
- 1) Has anyone seen this before????
- 2) Any suggestions????
-
- I am planning on working on it tonight, using the following procedure...
- - - Installing FSP 1.4 on the machine. (I have never used FluShot+, but from
- my understanding it is reliable).
- - - Running all of the software packages installed on the machine to find
- out if any of the programs on the hard disk call it.
- - - I will ask the people that used the machine in the last few days
- to use all of the software (on floppies) that they used while
- the machine is running under FSP.
- - - I am *not* sure this is a virus, but I don't understand how the
- file got into the root directory of the disk, as most of the users
- use the software on the hard disk or if they use floppies, it is to
- play games. (There are only 3 files in c:\ , command.com, config.sys and
- CBUG.COM and there are 4 subdirectories with utilities that we purchased)
-
- I am assuming that this procedure will help me find out 1) if it is a virus,
- and 2) the source of the virus if such a beast exists. There is always
- a possiblilty of this being a prank done by someone, but I cannot see
- it being one of our student or staff as none of them know enough about
- the IBM PC to create such a program. (we are a small college of 600
- students with a small percentage in computer related studies).
-
-
- Thanx for your time,
- Any help/suggestions/flames would be appreciated.
- Please reply directly to me, I will summarize to the list appropriately.
-
- CP6-Mail: Michael Brown @CMR
- NET-Mail: <brownm@cmr001.bitnet>
- Michael Brown Snail-Mail: Service Informatique CMR, St-Jean, Que. J0J 1R0
-
- ------------------------------
-
- End of VIRUS-L Digest
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