Worm.AutoRun.eav is a worm which may be downloaded unknowingly by a user when visiting malicious Web sites. This worm tends to modify the user’s registry entry so as to enable its automatic execution at every system startup. Worm.AutoRun.eav will drop copies of itself in all removable drives. Worm.AutoRun.eav also drops an AUTORUN.INF file to automatically execute its dropped copies when the said drives are accessed. It also updates itself from certain website. Worm.AutoRun.eav is renegade software that was designed to display false and exaggerated results, as a means to coerce a user into purchasing the full version software. Should a user actually download and install Worm.AutoRun.eav, then the program will start every time the computer is rebooted. Once started, it will scan the computer and state that the system can run more efficiently if the user purchases Worm.AutoRun.eav and lets it optimize the computer. In fact, it has been shown that by just having Worm.AutoRun.eav running on a computer can ensure the computer functions slower and run less efficiently. Worm.AutoRun.eav is installed under deceptive pretences, and it will infiltrate the user’s PC without their approval or knowledge. Worm.AutoRun.eav is particularly damaging to a computer system, once it has fully embedded itself within the PC’s system, therefore it is given a high priority security risk status by many computer analysts.