The conficker worm is rather nasty. It blocks access to security sites (those containing any of these strings: antivir ca. cert. conficker f-secure kaspersky mcafee microsoft msdn. msft. norton panda safety.live sans. symantec technet trendmicro windowsupdate), and it will auto update itsself to avoid detection (a pretty nifty idea). It is due to strike on April 1st (as a really bad April fools joke), but there is a real simple way to shut it down:
OpenDNS, a San Francisco–based company, provides a free, real-time service that prevents PCs from accessing phishing and hacker sites, among others. Admins of small and large LANs can use OpenDNS as a Domain Name System server.
On Feb. 9 the firm introduced a new, Conficker-specific feature. If an infected PC on a LAN somehow evaded detection, OpenDNS will prevent it from contacting Conficker’s control servers. Best of all, admins can read a report showing which PC tried to connect to a Conficker server.
For more details, read this announcement from them.
Another bonus, by using OpenDNS rather than your ISP’s DNS, you avoid those really annoying Rogers-style Oh No! We couldn’t find that page.