Additional Details
Upon execution, Perlovga.a acquires the drive letter from which the file is executed. It then opens the root folder of that drive and copies itself as xcopy.exe to the %windir%\xcopy.exe.
It then copies the file host.exe from the root drive of the current drive to %windir%\svchost.exe.
It then copies autorun.inf from the rot drive of the current directory as %windir%\autorun.inf, executes the file %windir%\svchost.exe and then exits.
For more details, read about it on our blog at
http://www.f-secure.com/weblog/archives/archive-012007.html#00001097