A new Trojan that hijacks Google text ads and replaces them with ads from a different provider has been picked up by BitDefender.
The antivirus company has identified the threat as Trojan.Qhost.WU which modifies the infected computer's host file, a local storage for domain name/IP address mappings.
The infected machine's browser then reads advertisements from a server at the replacement address rather than from Google.
"This damages users and webmasters because it takes away viewers and thus a possible money source from their websites," said BitDefender virus analyst Attila-Mihaly Balazs.
Users are advised to let antivirus software delete the Trojan.
Old viruses slipping under the guard
Trail leads back to China-based operations including a government website
Recent Swedish attacks raise worrying possibility
Do you agree?
Have your say on this article