The NanoCore RAT has been on the radar of threat actors and security experts since 2013. Several beta versions of NanoCore surfaced on the dark web between 2013 and 2014 before the most recent version was released in March 2015. This current version of NanoCore has expanded beyond the dark web and is readily available online.
Whether the original intent of NanoCore was to be a free tool for intrusions or a paid piece of software to be used legitimately is unknown.
Whatever the case may be, all current versions of NanoCore appear to have all base plugins and functionality available without restriction. Between NanoCore's availability, the low $25 price point, and the free "cracked" versions found online, the use of NanoCore has spread quickly.