Vicious Conficker worm malware still being tracked, but no clue on creator

The notorious malware known as the Conficker worm still infects computers, a sort of wild horse with no rider, but investigators appear no closer to finding its creator.

Also known as "Downandup," Conficker was discovered in November 2008, exploiting a vulnerability in Windows XP that allowed remote file execution when file-sharing was enabled. Microsoft patched it a month later.

A souped-up version of Conficker released that year later targeted the autorun feature in XP and Vista. At its peak, Conficker infected upwards of 7 million computers. Microsoft still ranks Conficker as the second-most prevalent malware family on domain-joined computers, according to figures released earlier this year in its Security Intelligence Report Vol. 13.

Security researchers with the Conficker Working Group (CWG) along with vendors including Microsoft successfully cut off the Conficker's operators from the botnet. The group is still working to try to find Conficker's master, said Jose Nazario, a malware researcher with security vendor Invincea, on the sidelines of the Hack in the Box conference.

The problem is that botnet operators have stayed away from Conficker and not tried to reclaim it, a welcome development but one that leaves researchers with a lack of fresh electronic leads.

"Well, we sort of won in that regard," Nazario said. "They had to walk away from it. On the other hand, if they're not interacting with it, there's no more evidence coming in."

In June 2011, Ukraine's security service, SBU made several arrests related to a cybercrime ring that defrauded the banking industry of more than US$72 million. The SBU indicated those arrested allegedly said they had used Conficker to spread fake antivirus software, another scam the group was accused of.

But the results of Ukraine's investigation are unclear. Conficker used a private key to sign encrypted updates, and if police found that key on a person's computer, it would represent the needed crucial evidence, Nazario said. But so far it has not come to light.

The CWG is still interacting with sinkhole operators, top-level domain operators and ICANN, Nazario said. The malware itself is on autopilot, taking advantage of vulnerable computers and has proved to be a long-term nuisance.

"It feels like a stalemate," Nazario said. "It feels like we're kind of in a holding pattern but there's still effort that goes into it."