Manually checked every script called by both the forums and main page as well as every widget. No malware found. I then did a site scan with website anti-virus scanners, one queried 66 antivirus tools, and it does detect SNH-gen [trj]. I checked the main site, forum index, board index, and a thread. None found any malware. It's most likely a false positive, or a local infection on your local machine.
