Media coverage of the Conficker superworm has died down over recent weeks but variants of the worm are still infecting 50,000 new PCs a day.

The US, Brazil and India are the main cultivation grounds for the worm, according to reports from the Symantec threat intelligence team.

Symantec has knocked up a colour-coded map illustrating the spread of the worm, which can be found here.

Conficker (aka Downadup) infects a Windows system by either exploiting systems unprotected against the MS08-067 vulnerability patched by Microsoft back in April, or by taking advantage of weak password security to spread across network shares. Infected USB sticks and other items of removable media can also spread the infection.

The worm infected millions of systems in the run-up to 1 April, where it changed the way it phoned home to pre-programmed servers to poll for updates. Nothing happened, apart from excitable media coverage of the date itself, but on 9 April some infected systems began to download additional items of malicious code via P2P update functionality built into the latest variants of the worm. The updated components included copies of the Waledac Trojan, a botnet application used to send spam.

Despite this there have been no reports of use of Conficker-compromised machines in either sending spam or running denial of service attacks. The overall population of the Conficker worm is constantly eroded by clean-up efforts, so even though 50,000 new machines might be getting infected every day the overall population of infected machines is probably in long-term decline.

The latest on malicious activities associated with the Conficker worm can be found on the Conficker Working Group website here. ®