Win32/Cleaman is a multi-component trojan with the capability to redirect web search queries. It is usually distributed via drive-by exploit kits and its main purpose is to redirect Bing, Google and Yahoo search results to either fake or compromised webpages that serve advertisements, adware programs and malware. Cleaman arrives with an obfuscated loader that drops the EXE and DLL component. It modifies the Windows Hosts file to redirect search engine access to a bogus server.Link: Microsoft Malware Protection Center