Every day, billions of dollars flow through the digital advertising ecosystem, providing the economic lifeblood of the internet as we know it. At the same time, ad fraud continues to evolve, surfacing in new formats, new threat types, and always hiding in the gray area. As advertising models increasingly shift toward performance-based metrics, such as pay-per-click and pay-per-conversion, fraudsters have found new opportunities to exploit the system, creating complex challenges that affect the entire advertising industry. Throughout these changes, click fraud has emerged as one of the key challenges in the landscape.