Sub7

Sub7, or SubSeven or Sub7Server, is a Trojan horse - more specifically a Remote Trojan Horse - program originally released in February 1999.

Because its typical use is to allow undetected and unauthorized access, Sub7 is usually described as a trojan horse by security experts. Starting with version 2.1 (1999) it could be controlled via IRC. As one security book phrased it: "This set the stage for all malicious botnets to come." Additionally Sub7 has some features deemed of little use in legitimate remote administration like keystroke logging.

Sub7 worked on the Windows 9x and on the Windows NT family of operating systems, up to and including Windows 8.1.