Google's AdSense program has been the subject of trouble from a Trojan, an antivirus firm BitDefender has announced. According to BitDefender, the virus, named Trojan.Qhost.WU, alters infected computers' hosts file and redirects the Google AdSense link to a various address. A virus analyst Attila-Mihaly says "This is a serious situation that damages users and webmasters alike".

"Users of adsense are affected as the advertisements and/or the linked sites might contain malicious code, which a very likely situation is given that they are endorsed using malware in the first place." Meanwhile, webmasters are hit because the Trojan grabs the viewers and, as a result, a possible source of revenue from their websites, he added.

Responding to the situation, Google commented: "We have cancelled customer accounts that display ads redirecting users to malicious sites or that advertise a product violating our software principles," Reuter's reports.