A malicious group in recent months has placed malicious ads on pornographic sites. These ads redirect users to explot kits and infect them with malware.
The group is called Malsmoke, and has carried out attacks on "almost all pornographic networks".
According to security company Malwarebytes, which monitors Malsmoke's attacks, most of the time, the group managed to place malicious ads on small or medium-sized pornographic portals, but recently "hit the jackpot" when it managed to add these ads to xHamster, one of the largest pornographic portals with billions of visitors every month.
Attacks can be seen as a last resort to infect users with old school tools such as exploit kits, the use of which has declined in recent years as modern browsers have become much more secure.
"Despite the recommendations of Microsoft and security professionals, we find that there are still many users (consumers and businesses) worldwide who have not yet switched to a modern browser." reports Malwarebytes.
"As a result, the authors of the exploit kit are targeting vulnerabilities in Internet Explorer and Flash Player."