Antivirus provider Eset has recently published a report (PDF) detailing what appears to be an ongoing criminal operation infecting more than 10,000 Unix and Linux servers.
The malware campaign, dubbed Windigo, sends spam and redirects end users to malicious Web pages. Eset indicated that Windigo has been running for upward of 36 months and has compromised more than 25,000 servers that can send upward of 35 million spam messages a day, and exposing Windows-based website visitors to malware attacks.
According to Eset researchers, the number of systems affected could seem small, but since each infected system is a server, a denial-of-service attack or a spam-sending operation (using just a few servers) is going to be more effective than those malware outbreaks which are performed from the desktop.