Symantec is warning about a new Trojan horse that encrypts files on compromised computers but offers no ransom note like other software designed to hold data hostage for a fee.

Instead, a Web search for terms related to the Trojan horse leads to a company offering a way to remove the malware. The company offering the product used to charge for it but now offers it for free.

Trojan.Ramvicrype uses the RC4 algorithm to encrypt files on systems running Windows 98, 95, XP, Windows Me, Vista, N...