Mystery infestation strikes Linux/Apache Web sites

According to a press release issued earlier this month by Finjan, a security research firm, compromised Web servers are infecting thousands of visitors daily with malware that turns their Windows machines into unwitting bots to do the bidding of an as yet unidentified criminal organization. Security firms ScanSafe and SecureWorks have since added their own takes on the situation, though with varying estimates on the number of sites affected. All reports thus far say the compromised servers are running Linux and Apache.

According to an article on, the exploit involves a rootkit installed on the compromised server that replaces several system binaries with infected versions. When the system is booted, the infected binaries are executed, and as a result, dynamically created JavaScript payloads are randomly and intermittently served to site visitors. The malware JavaScript attempts to exploit vulnerabilites in Windows, QuickTime, and Yahoo! Messenger on the visitor's machine in order to infect them.