Scores of Game of Thrones pirates may have had computers encrypted by ransomware after malvertisers served the dangerous malware through the Pirate Bay during the mega-series' season six première last weekend.

MalwareBytes researcher Jerome Segura says the hard-working Magnitude exploit kit authors were able to target pirates after they bought advertising space on the infamous Bittorrent website targeting users with pop-under ads.

Magnitude is a hugely successful crimeware offering that allows criminals to break into victim machines using a variety of browser and runtime exploits, some of which are zero days but most of which have been patched by the prudent.

The weekend attacks were consistent with the group's malvertising methods; Pirate Bay visitors would likely be quietly profiled and, provided their machine and browser specifications met the criminal's criteria, would then be silently compromised.

Victims do not need to click on anything to be compromised. The attack silently pops vulnerable browsers while the Pirate Bay ads are served to all visitors not running script blockers on the first search attempt.

Australians may be the most at risk; they have once again achieved the rank of the world's most prolific pirates of the Game of Thrones HBO mega series, accounting for a reported 12.5 per cent of all one million Bittorrent downloads of season six première The Red Woman on 24 April.

Segura says victims would be infected with the Cerber ransomware.

"Popular torrent site The Pirate Bay was serving ransomware via a malvertising attack this weekend," Segura says.

"The fraudulent advertiser was using a pop-under [ad] to silently redirect users to the Magnitude exploit kit and infect them with the Cerber ransomware."

NSFOCUS IB chief research analyst Stephen Gates says the malvertisers may be exploiting Adobe Flash Player (CVE-2015-7645, CVE-2015-8446, and CVE-2015-8651) and Microsoft Silverlight (CVE-2016-0034) vulnerabilities.

“In the past, the Pirate Bay has been notorious for hosting malvertising campaigns on their website," Gates said in a statement to The Register.

"If computers are not running the latest patches for these CVEs, the likelihood of infection runs pretty high, no matter where you’re surfing.”

There does not appear to be any way for victims to recover their Cerber-encrypted files save for restoring from backups or possibly paying the ransom which may not result in the provision of the promised decryption key.

The attacks are the latest in a rampage by criminals using the Angler exploit kit and cerber. Last week Segura detected some 400 malvertising attacks originating from advertisements bought through lone ad network AdsTerra. ®