Article View: comp.virus
Article #3146Re: SCAN 95b doesn't find MtE in EXE files (PC)
From: Vesselin Bontchev
Date: Wed, 11 Nov 1992 22:22
Date: Wed, 11 Nov 1992 22:22
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cjkuo@ccmail.norton.com (Jimmy Kuo) writes: > The argument for the second opinion says that if you detect the > infected form of the children, you will know if something is going on > in the computer. Once something is known to be affecting the > computer, theories related to integrity checking can take over. Files > such as those created above and certain files in reviewers' > collections cannot spread in that convoluted form and need not worry > endusers. (A version of this argument applies to whether it is > necessary to detect absolutely 100% of MtE mutations, i.e. integrity > checking takes over.) I tend to disagree. First, according to the above argument, you can always use an integrity checker to detect the second-generation infections, so you don't need a scanner at all. In fact, one of the arguments why the integrity checkers cannot replace the scanners completely, is that when you notice the infection, you usually want to find and remove all sources of infection, including the file that brought the virus to your system. Also, scanners are useful for scanning the software -before- you run it (something that the integrity checkers cannot do), therefore, the user wants to be able to find the viruses at that stage, not after the virus has been released in the system. Second, all the scanners mentioned by the original poster claim to be able to scan inside LZEXE compressed files. Therefore, if those claims are correct, they should be able to detect the virus. Third, some scanner -were- able to detect the virus. However, I agree with you, that in general the virus droppers (because what the original poster has done has been exactly to create a dropper) are not a serious problem. > It should be the form that propagates that we worry about. And though > you didn't note it, I'm sure all the files infected by your creations > were detected by all the packages above. Thus end-users need not > worry about your peculiar forms of MtE files because you're not going > to put those files on anyone else's computer. :-) Problem is, it is perfectly possible to create an MtE-based virus, converted in the way described in the original message, which will propagate in THAT FORM. Recall that we already have several viruses that are propagating in LZEXE or PKLITEd form... Regards, Vesselin - -- Vesselin Vladimirov Bontchev Virus Test Center, University of Hamburg Tel.:+49-40-54715-224, Fax: +49-40-54715-226 Fachbereich Informatik - AGN < PGP 2.0 public key available on request. > Vogt-Koelln-Strasse 30, rm. 107 C e-mail: bontchev@fbihh.informatik.uni-hamburg.de D-2000 Hamburg 54, Germany
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Path: arc1-ca.pugleaf.net!sparky!uunet!ornl!utkcs2!darwin.sura.net!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!usenet.ins.cwru.edu!cert!netnews.upenn.edu!netnews.cc.lehigh.edu!news From: bontchev@fbihh.informatik.uni-hamburg.de (Vesselin Bontchev) Newsgroups: comp.virus Subject: Re: SCAN 95b doesn't find MtE in EXE files (PC) Message-ID: <0011.9211121950.AA09997@barnabas.cert.org> Date: 11 Nov 92 22:22:31 GMT Sender: virus-l@lehigh.edu Lines: 52 Approved: news@netnews.cc.lehigh.edu