discovered my XP Pro native firewall was turned off via either desktop. Being on Cable with connection to net operating, I felt a heart attack this way comes! When I tried to re-activate it by ticking box to "Protect this computer" and hitting OK, got a warning saying could not due to some system dependencies not being there or running (network related). After trying several times including "repair this connection " with no luck, I finally resorted to a 4 day old System Restore point. Did solve problem but didn't explain how this could have happened in the 1st place. There is Zero chance I manually turned it off. Have noted several people in several forums having network (internet) connecting problems in the last week or 2. I thought they were SP2 related but not mine so I fear you maybe right with idea of new attack vector possibly trojan trying to slave others machines in prep for a Denial Of Service attack. My machine also registered all clean by AVG, ADAwareSE. Spybot etc. Good Luck! Happy