Web Security News

Gumblar malware spreading rapidly

Tuesday, May 19, 2009

Security researchers are warning that the malware known as Gumblar - which poisons Google search results with links to malicious sites and uses a back door to infect websites - is ramping up and spreading rapidly.

Gumblar uses a multi-stage attack that exploits bugs in Adobe Flash and PDF to install malware, which steals FTP credentials and takes control of the infected computer. Once the PC has been hijacked, the malware launches a man-in-the-middle attack to poison Google search results in Internet Explorer, researchers said.

The stolen FTP credentials are used to compromise any websites owned or operated by the victim. More victims are infected by encountering a compromised site. Web security firm ScanSafe said on its blog yesterday that the number of compromised websites has grown by 246 percent in just over a week, from when the firm began tracking the virus.

The U.S. Computer Emergency Readiness Team (US-CERT), a division of the Department of Homeland Security, yesterday began warning users that the US-CERT is aware of Gumblar and advised users to take precautions including the latest software security updates and anti virus products.

The attacks were first spotted in March, but the hackers have responded by using different IP addresses.

Gumblar is named for the domain gumblar.cn involved in the attacks, which has a Moscow IP, researchers said.