GrayFish is the crowning achievement of the Equation Group. The malware platform is so complex that Kaspersky researchers still understand only a fraction of its capabilities and inner workings. Key to the sophistication of GrayFish is its bootkit, which allows it to take extraordinarily granular control of the machines it infects.
"This allows it to control the launching of Windows at each stage," Kaspersky's written report explained. "In fact, after infection, the computer is not run by itself anymore: it is GrayFish that runs it step by step, making the necessary changes on the fly."