The text provides a comprehensive examination of the Kelihos botnet, detailing its origins, operations, and eventual neutralization. Initially derived from earlier botnets like Storm Worm and Waledac, Kelihos became a sophisticated peer-to-peer network primarily used for spam distribution, employing complex encryption to resist takedowns. Despite its robust design, Kelihos was dismantled in 2017 by the U.S. Department of Justice with CrowdStrike's assistance. The botnet was operated by Peter Yuryevich Levashov, also known as ZOMBIE SPIDER, who was arrested and later pleaded guilty to running the botnet for criminal purposes. The text delves into the technical intricacies of Kelihos, including its spam capabilities, malware distribution methods, and attempts at persistence and obfuscation. It also outlines the botnet's ancillary features, such as its ability to conduct distributed denial-of-service attacks and its involvement in click fraud schemes. Additionally, the text explores the possible connections between Levashov and the Russian government, although these remain speculative. The account concludes by noting the shift in criminal activities following Kelihos' dismantling, with other botnets taking over its role in the cybercriminal ecosystem.