IIS malware is a broad category of threats used in cybercrime, cyberespionage, and SEO fraud. “Internet Information Services web servers have been targeted by various malicious actors, for cybercrime and cyberespionage alike. The software’s modular architecture, designed to provide extensibility for web developers, can be a useful tool for attackers,” says ESET researcher Zuzana Hromcová, author of the paper.