Conficker's Big Day Passes Quietly, but Was It Really a Bust?

April 1 has come and gone in some parts of the world, and the Conficker worm is still here. While the day in security passed by relatively uneventfully, there are still people at risk.

The doomsday some were predicting the Conficker worm to bring had not materialized as of the evening of April 1. But that hardly means Conficker is a bust.

In short, the Conficker worm did what was expected-generate 50,000 domain names and begin contacting them. According to BKIS, the Bach Khoa Internetwork Security center, 1.1 million PCs in Europe, Asia and a part of America infected with Conficker have already "called home."

But even though nothing dramatic happened, AVG Technologies Chief Research Officer Roger Thompson warned against blowing the worm off.

"We expect that they have achieved their aim of building a fairly bulletproof botnet, and will now simply farm it, which means they'll probably harvest credit card numbers, bank accounts and identities from as many victims as possible, and then do it all again," Thompson said.

While the attention Conficker has generated may make infecting new computers difficult for the worm, those that are already infected are still targets for malicious activity, he noted. Though there are Conficker detection tools available, the worm does attempt to fool administrators into thinking they are not vulnerable by deploying a fake patch for the Microsoft vulnerability Conficker exploits.

To Thompson, the situation represents the natural evolution of botnets-and the consequence of the game of Whac-A-Mole played by the security industry.

"First, there were regular botnets, and they were getting shut down, so they tried making bulletproof hosting, which also got shut down," he said. "So they developed the idea of fast-flux botnets for command and control and then double-fast flux, and now Conficker."

More than functionality, it was the sheer number of PCs infected by Conficker that attracted so much attention. Though the exact number of compromised computers varies according to who is being asked, the general consensus is that millions of computers are still infected with Conficker despite the existence of removal and detection tools and a patch for the Microsoft vulnerability it targets. The compromised PCs could constitute one of the largest botnets ever.

"The whole purpose [of] botnets [is] to make money," said Jeff Shipley, security researcher for Cisco IntelliShield. "Either through spam or compromising data such as unauthorized access to credit card numbers and other critical data, botnets are a big underground business. Criminal usage of botnets is huge-in the billions of dollars."

There is also the possibility of selling Conficker's army of infected computers, but that could prove problematic due to the amount of attention it generated. Right now, countless members of the security community, including the Conficker Cabal-formally known as the Conficker Working Group-are keeping tabs on the worm. Even with 50,000 domains in question, those domains are being closely monitored and any malicious servers will likely be noticed before long.

"Given the profile of Conficker, I think it's rather unlikely that the botnet is up for sale," said Roel Schouwenberg, senior anti-virus researcher at Kaspersky Lab Americas. "Not a lot of people out there would like to handle such hot property, as the botnet is being watched by a lot of people. However, leasing [parts of] the botnet is a different story. That way the leasers would get the advantage of the power of the botnet, but the owners would still be running the risk."

Editor's Note: This story was updated to add information later supplied by BKIS on the number of infected computers it detected.