14 DAY TRIAL // Security researchers from Armorize have detected drive-by download attacks launched from two of the most heavily trafficked adult video websites in the world.
The malicious code was being loaded by rogue advertisements, commonly referred to as malvertizements, which made their way onto the websites.
One of the two affected sites occupies the 62nd place in top Alexa and receives over 23 million unique visitors per day.
The malicious ad was provided through an ad exchange service that took visitors through a series of redirects until landing them on a BlackHole exploit pack page.
This drive-by download kit checks what software visitors have installed on their computers and serves exploits for vulnerabilities in popular applications like Java or Adobe Reader.
The Armorize researchers point out that the malware installed by these exploits varied, but it included a version of the notorious SpyEye banking trojan.
The second adult website serving malicious advertisements is Alexa's top 113 position and has almost 11 million unique visitors every day.
The same malvertizement made its way on this website as well and was actually being served through the same ad exchange service.
"With these two sites having 23,873,546 and 10,885,350 unique visitors per day, respectively, and serving this malvertisement [...] since May 13th, there should have been a good number of infected visitors," the Armorize researchers conclude.
Malvertizing attacks are a serious problem that can affect even some of the most reputable websites. One of the most recent incidents involved popular music streaming service Spotify, whose free client displays advertisements during playback.
While most websites partner up with big advertising networks that heavily scrutinize the ads they serve, adult sites are more flexible in the ad exchanges they choose, and so the risk of attacks is probably higher.
Users are advised to always be prepared regardless of the type of websites they access. Keeping all software up to date, including the browser and the operating system, is critical in preventing drive-by downloads.