Acting U.S. Attorney Soo C. Song announced Monday a California man was sentenced to 24 months probation for initiating spam messages and accessing a protected computer without authorization.
Twenty-nine-year-old Sean Tiernan of Santa Clara developed malware programmed to infect computers through the victim’s use of social networking websites. Once the computer was infected, Tiernan would program the malware to receive direction and communicate with his servers over the Internet, according to court documents.
The servers, which the infected computers called back to, were previously “hacked.” The malware-infected computers and hacked servers formed a “botnet.” Tiernan controlled the botnet and utilized it to transform the victims’ infected computers into “proxy computers.” From the proxy computers, Tiernan would transmit a high volume of spam messages to other computers over the Internet.
Tiernan would also sell access to his botnet from at least August 1, 2011 to people who wanted to send out spam messages. A search warrant was executed at Tiernan’s residence on October 1, 2012. More than 77,000 bots or infected computers were active in Tiernan’s botnet. Some of the infected computers in his botnet were located in Pennsylvania.