Chrome and Firefox have blocked the official Kickass Torrents website because of malicious software that may compromise the machines of users who visit the website.
The news was first reported by Torrent Freak, which says http://kat.cr and https://kat.cr have been blocked by the world's two most popular web browsers on Friday.
Users who visit the website on Chrome are greeted with a red screen and a message that warns them against visiting the website.
"Attackers on kat.cr might attempt to trick you into installing programs that harm your browsing experience (for example, by changing your homepage or showing extra ads on sites you visit)," says Chrome.
Mozilla's browser shows a similar message.
"This web page at kat.cr has been reported to contain unwanted software and has been blocked based on your security preferences," the page on Firefox says. "Unwanted software pages try to install software that can be deceptive and affect your system in unexpected ways."
The warning messages have appeared because Google's Unwanted Software scanner, which are used in both Chrome and Firefox, seems to have detected malicious software that automatically downloads into a user's machine and compromises the system.
Specifically, the Safe Browsing diagnostic page for kat.cr shows two Trojans and one exploit present in more than a hundred pages of the website. The malware was discovered on Oct. 8.
The team at Kickass Torrents has confirmed the warning messages, pointing to a third-party advertiser who had malware incorporated in their ads. The team says the advertiser has already been removed, so the next review by Google and Mozilla will most likely get rid of the warning messages. In any case, users can still opt to ignore the warnings and head straight to the website itself.
This is not the first time a major web browser blocked Kickass Torrents due to unsafe ads. In July, Chrome issued the same warning on the Kickass website and other similar sites, including Torrentz, ExtraTorrent and RARBG.
Meanwhile, the Kickass team warns users against visiting copycat websites that it says are trying to exploit kat.cr's absence on the first page of Google's search results. When users search for the website, the first result that comes out on top is kickasstorrents.eu, which is not affiliated with the Kickass team. While some websites are simply proxies, others exist for the malicious purpose of selling expensive VPNs, gathering passwords and serving malicious ads.