Kaspersky Labs has discovered malware that inserts links to malicious Web pages within ASF media files, posing a danger to Windows users who download music files from P2P networks. Infected files launch IE and load a page that asks the user to download a codec. The download, a Trojan horse, installs a proxy program to route other traffic through the PC. The malware also has worm-like qualities, according to Secure Computing. It searches for MP3s, transcodes them to WMA format, wraps them in an ASF container, and adds links to further copies of the malware, all without modifying the .MP3 extension.