Deep Web, thanks to anonymity of its connection, provides to cyber criminals an ideal environment to grow up profitable business. German security firm G Data Software has detected a botnet with a particular feature, it is controlled from an Internet Relay Chat (IRC) server running as a hidden service of the Tor network. Security engineer Dennis Brown during the Defcon Conference in 2010 discussed the possibility of using Tor network to host botnet command and control servers. He proposed a couple of solutions to use Tor network for botnet infrastructure: Tor2Web proxy based model Proxy-aware Malware over Tor network”]
Source: http://securityaffairs.co/wordpress/8678/cyber-crime/botnet-pro-cons-of-using-tor-networks.html