Bagle Infection Rate Rolling Down

Security firms that monitor the presence of such worms on the Internet, such as MessageLabs,reported a downward trajectory in its spread.

MessageLabs reported that it intercepted over 120,000 instances worldwide of the Bagle.A worm on Monday alone, but this number fell to 40,000 on Tuesday, and Wednesday looked to be even slower. Interceptions in the Americas moved in the same direction, from 18,000 to 12,000 to far fewer on Wednesday.

Symantec also reported coincident infection in some cases of Trojan.Mitglieder.C. Spammers often use Mitglieder.C for an "open proxy," meaning that the software accepts surreptitious connections and commands and then uses the victims Internet connection to then send spam.

Security experts speculated over the possibility that Bagle.A was released prematurely. Its release came on the Sunday before Mondays national holiday in the United States.

This weekend arrival gave many IT departments and ISPs the lead time to firm up protection before the restart of business on Tuesday, stopping the worm before it had chances to spread widely.

During the time it did spread, according to MessageLabs, most of the detected infections came from Australia, although the geographic dispersal of the worm is very high.