Win32/Hydraq.B is a Trojan horse virus with a back-door remote controller that allows the intruder to retrieve system and user information, shutdown or reboot the system, execute commands on a remote shell, download and execute an arbitrary file, then save it to %Temp%\mdm.exe, escalate user privilege, copy, move, or delete files, and many other things. Viruses such as this one are increasing the stakes of IT security professionals.