This is a simple program to unlock files that have been encrypted with Virtumundo / Antivirus 2009 / etc. To use it, simply download the file and run it. It will automatically scan your My Documents folder for any encrypted files; any files it detects as corrupt will be renamed with a .bak extension, and replaced with the decrypted one.
Warning: Use this program at your own risk. Back up any important data before using it; I make no guarantee, express or implied, that this program will not destroy your files.
Note: since FileUnlocker will automatically unlock everything in your My Documents folder, you may want to temporarily move any large files (e.g., music, videos) to another folder so you can recover any important files first. I'd like to thank Julia Wolf of FireEye, Inc. for the decryption algorithm I adapted this program from. The Windows executable was packaged with JSmooth.