Lecna.d is a worm that spreads 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.d downloads from the Internet and executes arbitrary, potentially malicious files, which may setup other parasites. It also opens a back door providing the attacker with unauthorized remote 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.d is able to update itself via the Internet. It runs on every Windows startup.