Last night, computers infected with the Bagle Virus began to download a tool that can send spam by the hands of the Bagle spam gang.
Thousands of infected computers downloaded this tool from a server in Slovakia hosting a real estate site.
F-Secure uses automated tools to poll URLs used by virus writers to host bad malware, Hypponen said.
About 99 percent are decoys, set up to throw off attempts to track them down. But when a site suddenly becomes active, Hypponen said efforts are made to contact ISPs to shut them down.
The download link was also found on a French site hosted in the U.S. whose ISP has been contacted regarding the matter.