A stealthy malicious software program is taking hold in some of the most popular Web servers, and researchers still don’t know why.
Last week, security companies Eset and Sucuri found Apache servers infected with Linux/Cdorked. If that malware is running on a Web server, victims are redirected to another website that tries to compromise their computer.
Marc-Etienne M. Leveille of Eset wrote that the company has found 400 Web servers infected so far, of which 50 are ranked in Web analytics company Alexa’s top 100,000 websites.
“We still don’t know for sure how this malicious software was deployed on the web servers,” Leveille wrote. “One thing is clear, this malware does not propagate by itself and it does not exploit a vulnerability in a specific software.”