Full Disclosure mailing list archives
RE: A worm...
From: Nick FitzGerald <nick () virus-l demon co uk>
Date: Fri, 27 Jun 2003 14:24:42 +1300
"M. Osten" <lists () bleepyou com> to ATD:
And this was my point. Are the crafty "worm gods" creating worms that evade detection by using compression and other methods? If they are doing this, and if they are creating the "stealth worms" whats next. Zip files would be just one of hundreds of ways to hide worms. Maybe the virus scanning technology needs to be kicked up a notch or two.Do most virus scanners *not* scan compressed files? We scan all incoming mail using Amavis (on linux) with the NAI engine which does scanning of all the common compression schemes.
Most virus scanners do, by default, scan inside archive files (at least in their "on demand" forms and when in Email gateway and/or content inspection type roles). The main point is not whether scanners look inside archive files or not. The point is, if you are a new and thus "unknown to the scanners" malware, how do you get past the "security controls" in Outlook and Outlook Express and/or past the "block arbitrary files of this type regardless of what the virus scanner says" policies of many corporate Email gateway content scanners. Sobig.E's "ZIP trick" allows it to get past the attachment "security" restrictions of Outlook and the recent OE 6.0 service pack and, so long as a virus scanner's heuristic's did not fire on the executable inside the ZIP, would also allow it pass through many corporate Email attachment scanning policies too. That may only buy it a few more hours "freedom" but that can be more than enough to "get lucky" at some large corporate and thereby get sent to half the planet. -- Nick FitzGerald Computer Virus Consulting Ltd. Ph/FAX: +64 3 3529854 _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
Current thread:
- RE: A worm..., (continued)
- RE: A worm... Richard M. Smith (Jun 26)
- RE: A worm... Ron DuFresne (Jun 26)
- Re: A worm... Roy S. Rapoport (Jun 26)
- Re: A worm... morning_wood (Jun 26)
- SV: A worm... Peter Kruse (Jun 26)
- Re: A worm... ATD (Jun 26)
- RE: A worm... ATD (Jun 26)
- RE: A worm... M. Osten (Jun 26)
- Re: A worm... Brett Hutley (Jun 26)
- RE: A worm... Nick FitzGerald (Jun 26)
- Re: A worm... morning_wood (Jun 26)
- RE: A worm... ATD (Jun 26)