ProjectSauron

A couple of months ago, Symantec and Kaspersky Labs discovered a malware called ProjectSauron or Strider.   It was capable of harvesting passwords of entire networks since 2011.  It had separate modules designed to perform specific functions like stealing documents or recording keystrokes.  It is also highly selective in its target, currently only infecting 36 computers across 7 organizations in 4 different countries (Belgium, Sweden, Russia, and China).  ProjectSauron has been, until recently, undetected by some of the most advanced IDS/IPS systems available.

Symantec and Kaspersky is acknowledging that this may be state-sponsored malware, used for specific targets to gather military intelligence, because of the complexity of the technology used which may have caused millions of dollars to develop.

You can read more here: https://www.rt.com/news/355165-sauron-malware-cyber-espionage/