padgett%tccslr.dnet@uvs1.orl.mmc.com (A. Padgett Peterson) (03/04/91)
>From: Bob Bosen <71435.1777@CompuServe.COM> >What exactly is AI anyway? An explicit description is not suitable for a general audience, but I am told that the cows don't mind it a bit. >From: eldar@lomi.spb.su (Eldar A. Musaev) >Subject: Re: How to disable boot up from A: (PC) >That is very simple, if you have only one floppy. Open your computer >and set DIP switches and cable connections to make A: as B:... I used to think that this would work also but was chagrined (shimatta) to learn that many PC BIOSes check for floppy A as part of POST and will generate a "601" error and halt the boot process if drive A does not respond to the controller. >From: Bureau de Guerra <PH461A04@VAX1.UMKC.EDU> >Subject: Mac Viruses vs. PC Viruses: Coding Comparison >Because of 1,3,4, & 5 vs. 2, I conclude that programing a mac virus >is more difficult than programming a pc virus. >Jonathan E. Oberg ph461a04@vax1.umkc.edu True, it is probably more difficult for an amateur but orders of magnatude less than producing a good word processor. Also in the PC, a user must request a boot/execution of a virus while a MAC will execute floppy code without being asked. The "scan on floppy insertion" is possible (and should be a part of any good protection scheme) on the PC, it just hasn't been done yet (or has it, I am sometimes behind ?). >From: Bob Bosen <71435.1777@CompuServe.COM> >Subject: PC-DACS (PC) >two different versions I tested during 1988 and again in 1990 yielded >easily to attacks using only readily- available software tools brought >in on a bootable diskette.... Without hardware modification, >only ENCRYPTION can provide any kind of real security. >...and those few that are strong enough to enforce true security are >based on ENCRYPTION or HARDWARE or BOTH. Yup, confidentiality can be preserved with encryption, but only hardware can protect from destruction (if there is no FAT, it isn't DOS). However, the same software that redirects tables can also disallow writing to them. The question is one of risk vs cost just like the fact that experiments I have been making can be defeated easily manually if it is known to be there. Easy for a skilled person but very difficult for software unless directly targetted. The user has to decide the level of protection necessary and the price that is willing to be paid. My point is that a "normal" PC has NO defense and that quite a good level of protection from malicious software can be had with "simple" software techniques. Incidently, if a high level of CIA (confidentiality, integrity, & availability) is needed, Mr. Bosen's products are very good. (personal opinion). Padgett Note to indexer: all paragraphs relate to PC protection with the exception of AI which doesn't relate to anything.