Hoosmi is a trojan. Once executed, it drops and opens a Microsoft Word document, and installs itself to the system. Then it runs a payload. Hoosmi starts logging all user keystrokes. It also downloads from the Internet and executes malicious files, which can setup other dangerous parasites. The trojan uses an integrated rootkit in order to hide its presence in the system and avoid detection. Hoosmi runs as a service on every Windows startup.