The torrent site Demonoid was blocked by Google after tests by the search giant found that pages within the site - often used to trade music and films - contained banner adverts which were installing malware on users’ PCs.

On Google searches, potential visitors were warned, “This site may harm your computer,” and were redirected to a malware warning page for several days, rather than the site itself, The Guardian reports.

Digital Trends reports that the site blamed banner adverts for the infections - which affected a few pages within the site, according to Google. Demonoid has strict rules on torrents - and pornography, malware and exploit kits are banned.

SC Magazine reported that the torrent tracker immediately removed all advertising until it tracked down the culprit. Mozilla also issued a similar malware warning.

The ban has now been lifted. In a statement, the site said, “We run content from a lot of ad networks in our ad banners, and a lot of banners from each. One of those banners started serving malware, so we disabled all ads until we are 100% sure of the culprit and get it removed. We are also taking the proper steps to get us out of all the blacklists.”

Google said, “Of the 75 pages we tested on the site over the past 90 days, 4 page(s) resulted in malicious software being downloaded and installed user consent.”

After what Demonoid described as a “vacation”, the site is now back online. The site said, “Sorry for the hassle. One of those banners started serving malware, so we disabled all ads until we are 100% sure of the culprit and get it removed. We are also taking the proper steps to get us out of all the blacklists.”

A We Live Security guide to how to rid your PC of adware and “badware” can be found here.