Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ucselx.sdsu.edu!polyslo!vlsi3b15!vax1.cc.lehigh.edu!sei.cmu.edu!krvw From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.virus Subject: Re: Universal virus detector Message-ID: <0012.9002051554.AA01695@ge.sei.cmu.edu> Date: 2 Feb 90 16:53:56 GMT Sender: Virus Discussion List Lines: 27 Approved: krvw@sei.cmu.edu > For example, you can add a > hardware-enforced switch which when in the OFF position makes it > impossible to set the "is executable" bit at all. So far so good. > In this mode, you > can't do program development, install new executables, or even copy > executable files - Pretty much so. > but you absolutely can't be infected either. Not true. What constitutes an "executable file"? Is a BASIC program one? You can write a virus in BASIC. How about Postscript? You can hide a virus in Postscript. You can't turn off your BASIC or Postscript interpreters... This is the basic sort of protection used by old Burroughs computers: only the compilers could create executable files, and they were trusted programs. They had no memory protection hardware at all. - -- _--_|\ Peter da Silva. +1 713 274 5180. . / \ \_.--._/ Xenix Support -- it's not just a job, it's an adventure! v "Have you hugged your wolf today?" `-_-'