OSX/iWorm is a persistent backdoor that allows an attacker complete remote control over infected hosts. It was was distributed via trojanized pirated applications that were hosted on Pirate Bay and used reddit.com for command and control (C2) [1].

References:

1. https://www.virusbtn.com/pdf/magazine/2014/vb201410-iWorm.pdf
2. http://www.intego.com/mac-security-blog/iworm-botnet-uses-reddit-as-command-and-control-center/