Have you experienced that when you boot your Windows XP in Safe Mode the message appears:

Thank You!!!
Password:Winzip123

It appears just after a command prompt is executed a file which is found and detected by Symantec as W32.SillyFDC. Some other files found and detected related are password_viewer.exe and autorun.inf.

This worm may be hard to remove by using typical virus scanning because even Antivirus running on computer can be disabled by the worm. It can also disable various Windows process needed for the removal such as Task Manager, Registry Editor, Run and others.

Removing this worm can be perform successfuly by following the W32.SillyFDC removal found here. Another way to remove it without going through the long process requires technical capabality by physically detaching the infected hard drive and scanning it on a clean computer. Complete procedure can be found here.