Last month, users were more likely to be struck by trojans than any other kind of virus.
The main threat was Clicker.CM. an ad-serving trojan. Also prevalent were three variants of the Wimad trojan downloader, according to a report from security firm BitDefender. The Wimad trojan takes on the appearance of a codec downloader.
The Trojan.Qhost.AKR, a piece of malware that tries to disable anti-virus updates, was the fifth most widely seen, and a Flash exploit and the Trojan.Swizzor.1 virus were next.
An an ActiveX control exploit called SinaDLoader ActiveX was the eighth most seen. This one tricks a browser into downloading and installing malware.
The last two were a virus that spreads via peer-to-peer file sharing and a downloader for a fake anti-virus package called “XP Antivirus.”
Sorin Dudea, head of virus research at BitDefender said in a statement: “XP Antivirus has had previous forms. It used to appear with a valid digital signature and a lengthy [end-user license agreement0, from sites with security-related names. As such it was somewhat of a champion in the social engineering area, convincing victims that it was in fact a legitimate piece of security software.
"Measures taken to revoke the malware's digital signature by GlobalSign [an SSL certificate provider] and the denial-of-anonymity to the people who ran sites hosting it by Directi [a web services firm], seem to has put a dent in the operation,” he said.