W32/Rbot-UI is a Windows network worm which attempts to spread via network shares. The worm contains backdoor functions that allow unauthorised remote access to the infected computer via IRC channels while running in the background.
The worm spreads to network shares with weak passwords and also by using the LSASS security exploit (MS04-011) and RPC-DCOM security exploit (MS03-039).
When run W32/Rbot-UI moves itself to the Windows System folder as a hidden, read-only, system file named npfw.exe.
The worm then creates the following registry entries so as to run itself on computer logon:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
Norton Personal Firewall
npfw.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
Norton Personal Firewall
npfw.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Norton Personal Firewall
npfw.exe
Once installed, W32/Rbot-UI will attempt to participate in denial of service (DoS) attacks, download and run files from the internet, steal CD keys, log keystrokes and login to MS SQL servers and send EXEC commands to open a command shell when instructed to do so by a remote attacker.