A Botnet is a network of compromised computers; while not a form of malware, a botnet can be the consequence of a malware attack. Often created by a Trojan horse or a worm, a botnet can be used to send spam or to attack computers. For example, security researchers at Intego discovered a Trojan horse responsible for a Mac botnet in January, 2009, hidden inside pirated copies of popular Mac software.
- Conficker (a.k.a. Downup, Downadup or Kido) was the cause of perhaps the largest botnet is history. It was first detected in November 2008, and targeted the RPC port (number 445) of the Windows XP operating system. There where five versions of this worm released, to deal with the efforts of "Cabal" which tried to stop it.
- Intego Security Alert. Mac Trojan Horse OSX.Trojan.iServices.A Found in Pirated Apple iWork 09, intego.com, January 22, 2009.
- New Variant of Mac Trojan Horse iServices Found in Pirated Adobe Photoshop CS4, The Mac Security Blog, January 26, 2009.
- Worm: The First Digital World War by Mark Bowden