By Elinor Mills
Wednesday, April 01 2009 08:55 AM
URL: http://www.zdnetasia.com/news/security/0,39044215,62052732,00.htm

The Conficker worm is stirring on some infected computers in Asia where it's April 1, but so far the activity is very tame, security researchers say.

"We've seen activity in honeypot machines in Asia.... They're generating the 50,000 list of (potential) domains to contact," said Paul Ferguson, an advanced threats researcher for Trend Micro.

The latest variant of the worm, Conficker.C, was set to activate on April 1, which for some of the infected machines will happen at local time and for others it will be GMT, depending on whether the machines are turned on and connected to the Internet, he said.

The process seems to be starting slowly, with infected machines starting to generate the list of domains and then picking one domain and trying to contact it and waiting before continuing on through 500 of those 50,000 domains, according to Ferguson.

The owners of the infected computers likely won't notice anything, unless they can't access the Web sites of security vendors and then they will know they are infected, he said. Trend Micro has figured out a way to unblock the computer from the sites that the worm has blocked using a Microsoft networking service, he said. More details are on the Trend Micro site.

"Nothing at this point; we're running updates every half hour or so," Dave Marcus, director of security research for McAfee Avert Labs, said when asked to report what he was seeing. "They're supposed to connect to one of a variety of Web sites and download a piece of code. What that code is supposed to do is up in the air."

IBM ISS's X-Force group also reported that things were quiet, at least for the moment, in Asia where most of the infections are. Nearly 45 percent are in Asia, followed by Europe at about 30 percent, according to the Frequency X blog.

IBM ISS also said it had found a way for ISPs to detect infected computers on a network by monitoring the peer-to-peer communications the worm makes between infected PCs.

Experts say the worm could be used to steal passwords or other sensitive data from infected computers, or turn them into a botnet that sends out spam.

The worm exploits a vulnerability in Windows that Microsoft patched in October and spreads through weakly protected network shares and via removable storage devices, like USB drives.

Conficker.C also shuts down security services, blocks computers from connecting to security Web sites, and downloads a Trojan. It reaches out to other infected computers via peer-to-peer networking, in addition to being programmed to reach out to 500 domains to receive updated copies or other malware instead of just 250 domains as earlier versions did.

This article was first published as a blog post on CNET News.