I think this is the Telnet service running, and someone is possibly exploiting a security breach in Windows. Download latest updates and SPs, and disable the Telnet service.(Go to Start, Run, type services.msc, scroll down to Telnet, right-click, go to Properties, and on the drop-down list, select Disabled and click Apply)
If not, run this tool:
(Only if you are not running Windows NT, 2000, or XP)
If this doesn't help, I will think about it some more.