Archiveus

Archiveus is an early ransomware Trojan identified in 2006 that targets Microsoft Windows systems. It is notable as one of the first ransomware families reported to use 1,024-bit RSA encryption, marking an early step in the evolution from crude extortion malware to stronger cryptographic ransomware. Archiveus encrypts victim files, with reporting indicating a primary focus on data stored in the user's documents directory, and then withholds access in exchange for victim action intended to benefit the operators.

Unlike later ransomware families that typically demanded direct electronic payment, Archiveus used an extortion model in which victims were instructed to purchase goods from designated online stores in order to receive a decryption password. The malware required a long password to restore access to encrypted data. Its protection scheme was later broken, which significantly reduced its effectiveness.

Archiveus is consistently characterized as a Windows ransomware Trojan rather than a worm or self-propagating threat. It played an important historical role in ransomware development by demonstrating stronger asymmetric encryption in criminal extortion malware, even though it is no longer considered a prevalent threat.