This is a PS-MPC-based virus, which spreads in an encrypted form.
The encryption layer is done with a shareware utility called
Protect! COM/EXE v4.0.
This virus is not common at all. However, false alarms of it are
quite common, since some versions of TBScan and Intel Lanprotect
identify all files protected with Protect! v4.0 as infected by
[Analysis: Mikko Hypponen, F-Secure]