Trojan hijacks Google Ads

According to security researchers at BitDefender a new Trojan has been discovered which hijacks text based Google adverts and replaces them with ads from a totally different provider. Trojan.Qhost.WU acts by modifying the infected computers' Hosts file to include a line which redirects the web browser from the expected .googlesyndication.com IP address to another which ensures that the browser gets its ads served from a completely different place instead of Google.