Troj/Mailbot-BX is an IRC backdoor Trojan for the Windows platform.
Troj/Mailbot-BX gives a remote intruder access to a compromised computer, and allows them to send arbitrary emails, making the infected computer act as an email proxy.
When run Troj/Mailbot-BX copies itself to <System>\plsitctl.exe.
The following registry entry is set to run Troj/Mailbot-BX on startup:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
dstiosys
<System>\plsitctl.exe