Beware of websites booby-trapped by newly energized ShadowGate group, researchers warn.

The attacks install three pieces of malware using an exploit kit called GreenFlash Sundown, which researchers identified in 2015 and have continued to follow since.

The most notable compromise is of an ad server belonging to onlinevideoconverter[.]com, a site with more than 200 million visitors per month that converts YouTube videos into video files that can be stored on a computer hard drive.

The best way to protect against this campaign is to be sure to keep browsers, browser add-ons, and operating systems updated, since the attackss this group is known to use almost always exploit known vulnerabilities for which patches are available. Antivirus protection is also effective, since most engines detect both the exploits and the payloads. Additionally, it’s almost never a bad idea to uninstall stand-alone versions of Flash.