BoScript

Several variants of this pest can be found in the internet under such
names as BoScript and BoScript 0.2. This hacker tool was designed to
control user's PC from a distant machine. The hacker infects his
victim via the e-mail or File and Print Sharing with a "server"
application. This application opens a default port and awaits commands from the
attacker. The intruder communicates with the "server" via a "client"
application on his PC. Sometimes the RAT is combined with a Trojan virus.
It helps the attacker to infect the computer via the e-mail. Variants of
this virus appeared from August 1998 to February 2002.