Conficker.c infects small number of U.S. PCs, IBM says

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Conficker Worm

• Conficker's makers lose big, expert says
• Conficker activation passes quietly, but threat isn't over
• FAQ: Just the facts on Conficker
• Security managers concerned but confident about Conficker on eve of expected attack
• IBM: Conficker.c infects small number in U.S.
• Security software scammers riding on Conficker's coattails
• Researchers exploit Conficker flaw to find infected PCs
• Conficker's next move a mystery to researchers

More: Malware Knowledge Center

Computerworld - Conficker.c may be in headlines around the world, but most of the infected PCs are in Asia and Europe, with fewer than 6% of the total in North America, a security company said today.

Using an analysis of the worm's peer-to-peer communications scheme, IBM Internet Security System's X-Force team figured out last week how to detect machines plagued with the newest variant of Conficker, then mined that data to put a face on its geographic distribution.

"A lot of people have been reporting on infections that they've seen, but we really hadn't seen who was infected now," said Holly Stewart, X-Force's threat response manager.

As of Monday, 45% of the Conficker.c-infected computers were traced to Asian IP addresses, while another 31% were pegged to European addresses. South America accounted for 14% of the total, and just 5.8% of the infected PCs were using IP addresses associated with North America, Stewart said.

The dominance of Asia on the roll call of infected regions isn't surprising. Last Friday, Nguyen Tu Quang, chief technology officer at Bach Khoa Internetwork Security (BKIS), which is housed at the Hanoi University of Technology, said that all fingers point to China. "It is almost certain that Conficker has Chinese origins," Nguyen said in an e-mail.

Conficker.c has received a massive amount of attention, especially in the last week, as tomorrow approaches. The third variant, which researchers first spotted earlier this month, will be able to switch to a new method of getting orders starting April 1.

Earlier versions of the worm generated a list of 250 possible domains each day that the malware could use to route instructions from its controllers, but Conficker.c cranks out a list of 50,000 Web addresses daily. Most researchers believe that's a direct response to work begun last month by the so-called Conficker Cabal -- officially known as the Conficker Working Group -- an ad hoc consortium of researchers and companies that have tried to disrupt the worm's "phone home" ability by registering as many of the daily domains as possible.

"Conficker.c makes it really hard for researchers to crack the communications code," Stewart said, referring to the worm's beefed-up peer-to-peer skills, which some believe were added as a fail-safe link to the headquarters of the hackers who created the worm if the domain routing system was compromised. Conficker.c has been using its peer-to-peer communication connection since it debuted.

"If you looked at the simple information on the wire, it might be mistaken for VPN traffic," Stewart added. "But our researchers cracked the way that they were using peer-to-peer." Using that information, X-Force has been able to sniff out Conficker.c-infected machines by detecting the worm's "fingerprint" in the traffic it monitors coming in to and going out of its customers' networks.