Hackers planted malicious script on the site of an Indian anti-virus firm this week. The website of AVsoft Technologies was attacked by unidentified miscreants in order to distribute a variant of the Virut virus.

AVsoft Technologies makes the SmartCOP antivirus package. One of the download pages of the site was boobytrapped with malicious code that used the infamous iFrame exploit to push copies of the Virut virus onto visiting unpatched (or poorly patched) Windows PCs.

The technique is a popular method for turning the websites of legitimate organisations in sites for drive-by malware downloads. Virut opens up a backdoor on infected PCs, allowing hackers to download and run other malware (or anything else they fancy) onto infected computers.

The compromise of AVsoft's site came to light via a post on a full disclosure mailing list on Thursday. It's unclear whether of not AVsoft has since purged its site (which remains available) of nasties. ®