Dec 20, 2011 A LOIC (Low Orbit Ion Cannon) is one of the most powerful DOS attacking tools freely available. If you follow news related to hacking and. Low Orbit Ion Cannon (LOIC) is an open source network stress testing application, written in C# LOIC performs a DoS attack (or when used by multiple individuals, a DDoS attack) on a target site by flooding the server with TCP or UDP. Dec 13, 2014 LOIC download. LOIC 2014-12-13 05:09:46 free download. LOIC A network stress testing application.