Adware and ad fraud are in the same business and both dont care how they make money, as long as it keeps pouring in. The main victims of adware are the users that may have knowingly installed advertising supported software, in the case of ad fraud the main victims are the advertisers. The malware involved in this type of fraud is usually classified as a Trojan as the systems are remotely controlled and told to visit a site (to heighten the popularity) or click a URL (to register an impression)”]
Source: https://blog.malwarebytes.com/cybercrime/2017/03/adware-vs-ad-fraud/