Malware, Patch/Configuration Management, Vulnerability Management

Conficker attempting to infect 50,000 per day

Updated Thursday, May 21, 2009 at 4:58 p.m. EST

Publicity around the Conficker worm has been relatively quiet for the past month, but security researchers say it hasn't gone dormant.

The worm is attempting to infect approximately 50,000 new PCs a day on average, the Symantec threat intelligence team estimated. That indicates that there are compromised systems actively trying to find other systems to compromise, Dean Turner, director global intelligence network at Symantec, told on Thursday.

The United States, Brazil and India top the charts as the countries with the most infected computers worldwide, each with more than 340,751 infections since February. Though it seems, according to Syamtec's heat map of the spread of Conficker since February (below), that nearly every country in the world has been affected.

There are numerous variants of this worm, but researchers said that computers with the B++ and C variants are the ones actively trying to infect new users.

The most recent variant is Conficker.E, in which Conficker-infected machines began attempting to contact Waledac domains to install binaries belonging to the notorious spam bot. Since the Conficker.E variant started dropping Waledac in early April, the worm hasn't changed -- likely because those behind it want the media hype to die down, experts said.

“The people behind this may have brought more attention to themselves than they hoped,” Turner said. “They have been quiet to protect what they have.”

Turner said researchers still don't know why the worm was created. They think it is linked to the distribution of malware and rogue anti-virus, but nobody really knows for sure. But what it really is, Turner added, is a large bot network that awaits commands from the people behind it.

David Perry, global director of education at TrendMicro told Thursday that Conficker is a huge criminal enterprise, likely run by the Russian mob, with numerous variants and hundreds of files involved.

Essentially, it is a huge botnet of approximately 10 million machines, with different infection versions -- some carrying spam, some attempting to further propagate the worm. 

“The consensus among malware experts is that these people are hiring themselves out to different criminals for different criminal purposes, Conficker is the botnet for hire,” Perry said.

By now, almost all of the anti-virus vendors have Conficker removal tools and a patch has been available for the Microsoft Windows Server service vulnerability (MS08-067) being exploited to spread the worm. But still, it is not unusual to see lingering attempted infections, Turner said.

That fact is an indication that there are still infected systems out there. Some users have not updated anti-virus signatures, installed the Microsoft patch, or run a removal tool, Turner said.

A heat map of the spread of Conficker since February, courtesy of Symantec.

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