PGPCoder.A is a Trojan that encrypts all the files with any of the following extensions: ASC, DB, DB1, DB2, DBF, DOC (Word documents), HTM, HTML, JPG (pictures), PGP, RAR (files compressed with WinRAR), RTF, TXT (text files), XLS (Excel spreadsheets) and ZIP (files compressed with WinZip).

The user will not be able to open those files until they are decrypted. PGPCoder.A instructs users to send a message to an email address so that they can buy the decrypter. PGPCoder.A does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.

Technical details can be found at this Panda Software page.