SpyHunter by Enigma Software Group USA, LLC is a program that was previously listed as a rogue product on the Rogue/Suspect Anti-Spyware Products List because of the company's history of employing aggressive and deceptive advertising. It has since been delisted but some users have reported they still engage in deceptive advertising. Newer versions of SpyHunter install it's own "Compact OS" and uses Grub4Dos loader 3 to execute on boot up. The user no longer sees the normal Windows boot menu but instead sees the GRUB menu. In some cases this has caused the computer to go into a continuous loop or experience other issues when attempting to boot.