The notorious Conficker worm, which began infecting Windows systems in 2008 but has not had a new variant in more than two years, continues to dog enterprises more than three years later, according security experts at Microsoft.
For the past two-plus years, Conficker has remained the top malware threat facing businesses, having been detected almost 220 million times worldwide since 2009, according to the software giant. Theres been a 225 percent increase in quarterly detections since that year, and in the fourth quarter of 2011 alone, the worm was detected on 1.7 million systems.
"Many ¦ in the enterprise are still fighting that worm," Tim Rains, Microsofts director of trustworthy computing, said April 25 in a conference call with reporters to introduce the latest Microsoft Security Intelligence Report.
Microsoft releases its Security Intelligence Reports twice a year, drawing on data gathered from the more than 600 million Windows systems in use worldwide, the 280 million Hotmail accounts that scan billions of emails, billions of Web pages scanned by Bing every day and the various security software and toolsincluding Microsoft Security Essentials and Malicious Software Removal Toolfrom the software giant.
"We have a pretty rounded view of the threat landscape," said Rains, who also talked about the report in an online video.
From that and discussions with enterprise customers, he said Microsoft officials have continued to find that Conficker is the biggest malware problem for businesses, despite the lack of variants of the worm and that Microsoft issued a patch to shore up the vulnerability soon after Conficker was detected. Rains said Microsoft officials wanted to know why the worm continued to propagate.
The Conficker worm exploited a remote code execution flaw in Windows, and at one point had infected as many as 7 million Windows-based systems. The Conficker Working Group was organized to take control of the worms command-and-control (C&C) server to slow the rate of infections and help monitor Conficker.
A review of the problem last year mirrors what security experts years ago said were the key culpritsthe use of weak passwords and systems that had not been patched to close the vulnerability, Rains said. About 92 percent of all the recent infections are due to the use of weak passwords by users; the other 8 percent are due to systems being unpatched. That indicates that the bulk of new Conficker infections are easily avoidable.
Conficker operates with a relatively small library of basic weak passwords that it uses on systems within a network. Once it steals the Admin password, Conficker immediately uses it to log into every other PC on the network and compromise those systems, according to Microsoft.
A look at the passwords on the systems compromised last year shows a laundry list of weak passwords, from "admin123," "Login," and "manager" to "0987654321" and "test."
"The use of these weak passwords is very concerning," Rains said.
The best way to protect against Conficker is for enterprises to adhere to the fundamentals: develop strong password policies, apply all available updates, use trustworthy antivirus software and invest in the newest operating systems, which tend to be more secure than older versions, he said. Rains also suggested that for those businesses that dont have strong in-house IT expertise to consider using the cloud for their business resources.
Qualys CTO Wolfgang Kandek, commenting on the latest Microsoft security report, echoed Rains frustrations when talking about how Conficker has been able to continue spreading despite the easy and available remedies.
"Reading through the report, it is clear that we have the means to block each and every attempt of conficker to infect other machines," Kandek wrote in an April 25 post on the company blog. "In all fairness, the overall numbers are dragged down by the consumer-side of Windows.
"Enterprise installations have better values, almost completely eliminating the Autorun vector, and bringing the vulnerability-based attacks down to 12 percent on Windows XP," he continued. "Nevertheless, credential attacks continue to be effective, accounting for over 90 percent of all successful attempts, clearly showing that while patching has gained good acceptance, secure configurations are still a challenge."