In message <005701c2c4b1$165b1a80$0c01a8c0(a)saarinen.org>, "Juha Saarinen" writes:

Joe Abley wrote:

...

http://www.nextgenss.com/advisories/mssql-udp.txt

http://news.bbc.co.uk/1/hi/technology/2693925.stm Although I remain dubious about this claim: "Unlike viruses, the worm exists only in memory, so it cannot be detected by traditional anti-virus scanners."

I'm not sure which bit you're dubious about: the "only in memory" or the "cannot be detected by traditional anti-virus scanners". The only in memory has been identified by various people starting to disassemble it. Various useful links (that have come through Bugtraq):

From "Jay D. Dyson" :

http://www.kb.cert.org/vuls/id/370308 http://www.kb.cert.org/vuls/id/399260 http://www.kb.cert.org/vuls/id/484891

From H D Moore :

http://www.digitaloffense.net/worms/mssql_udp_worm/ (which contains some disassembly screen shots, and a unannotated disassembly)

From cstone

http://www.boredom.org/~cstone/worm-annotated.txt (which contains an annotated disassembly)

From what I can tell it's just a worm, spreading itself as fast as it can. Presumably the vulnerable hosts thus identified are then prime targets for something else to come in as a second wave.

There's nothing in the annotated disassembly that indicates writing/sending data anywhere other than the Internet, hence "only in memory". Various people report that the infection can be cleared by stopping SQL server and/or rebooting -- with the obvious caveat that if it's not disconnected/firewalled from possible sources, it'll be reinfected quickly. As for "cannot be detected by traditional anti-virus scanners", that's probably a fall out of not writing anything to disk (which could be scanned), and memory protection in modern OS (which means the "memory scan" phase of DOS-based virus scanners is limited to the memory space the anti virus scanner is running in, without kernel support). Presumably a debug API or similar could be used to scan all memory, but I don't recall seeing that type of technique in (m)any anti-virus programs. Ewen - To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog