Skynet is a Tor-based botnet that spreads via Usenet downloads and has capabilities including Tor communication, credential grabbing, DDoS attacks, IRC, and Bitcoin mining. It comprises around 15MB and includes components like a Tor client, Zeus bot, CGMiner, and OpenCL.dll. The botnet sizes is estimated at over 12,000 infected systems spread globally. The document discusses the botnet's command and control panels and provides examples of IRC commands. It also covers the botnet's Bitcoin mining behavior and potential future adoption of Tor by other botnets.