Troj/Rbot-ACT is a Windows Trojan which contains backdoor functions that allows unauthorised remote access to the infected computer via IRC channels.
When run Troj/Rbot-ACT copies itself to the Windows System folder as msnmcgrs.exe and creates the following registry entries to run itself on user logon:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
strmsnnrs
msnmcgrs.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
strmsnnrs
msnmcgrs.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run
strmsnnrs
msnmcgrs.exe
Once installed, Troj/Rbot-ACT will attempt to download files from the internet and run them and acts as a HTTP proxy when instructed to do so by a remote attacker.