HLIN@NAS.BITNET (Herbert Lin) (11/06/90)
I'm looking for a virus checker for an IBM PC that has the following characteristics: - -- Not memory resident, and so does not check for infections in real time - -- runs any program I call after first checking a checksum or CRC against a pre-stored library (and warning me if a difference is found). - -- user-adjusted formula for checksumming - -- will calculate checksums for me. In other words, I'm willing to accept an infection once, but not to have it run. anything out there? thanks. Herb Lin HLIN@NAS (from Bitnet) HLIN%NAS.BITNET@CUNYVM.CUNY.EDU (from Internet)
frisk@rhi.hi.is (Fridrik Skulason) (11/13/90)
HLIN@NAS.BITNET (Herbert Lin) writes: >I'm looking for a virus checker for an IBM PC that has the following >characteristics: > >- -- Not memory resident, and so does not check for infections in real >time > >- -- runs any program I call after first checking a checksum or CRC >against a pre-stored library (and warning me if a difference is >found). There are some programs which attempt to do this, but unfortunately it is nearly impossible. The reason is the existence of 'Stealth'-type viruses, where a program appears unchanged after infection. So, if you run a program infected with one of those viruses, all your programs may be infected, without appearing to change in the slightest. The program will not catch the first infected program (assuming it is new and not in the database), nor will it catch programs executed later (as the virus is then in control) Now ... I am not saying it is impossible, just that many current programs have problems with this... - -frisk