Lecna is a worm that spreads through network shares by exploiting known Microsoft Windows vulnerabilities. Once executed, the parasite secretly installs itself to the system and starts a spreading routine. Then it runs a payload. Lecna downloads from the Internet and executes arbitrary, potentially malicious files, which may setup other parasites. Furthermore, it opens a back door providing the attacker with remote unauthorized access to the compromised computer. The intruder can manage and run files, terminate active processes, search for and infect vulnerable hosts, uninstall the worm. Lecna is able to hide its presence in the system by using an integrated rootkit. The worm runs on every Windows startup.