On April 7, 2017, Pytor Levashov — who predominantly used the alias Severa or Peter Severa and whom Falcon Intelligence tracks as ZOMBIE SPIDER — was arrested in an international law enforcement operation led by the FBI. ZOMBIE SPIDER’s specialty was large-scale spam distribution, a fundamental component of cybercrime operations. Levashov was the primary threat actor behind a botnet known as Kelihos and its predecessors, Waledac and Storm. In addition to Levashov’s arrest, there was a technical operation conducted by Falcon Intelligence to seize control of the Kelihos botnet.