The MS-ISAC has recently observed an increase in malware that is most often disseminated through malvertising. Malvertising, or malicious advertising, is the use of online, malicious advertisements to spread malware and compromise systems. Generally this occurs through the injection of unwanted or malicious code into ads. Malicious actors then pay legitimate online advertising networks to display the infected ads on various websites, exposing every user visiting these sites to the potential risk of infection. Generally, the legitimate advertising networks and websites are not aware they are serving malicious content.