Polymorphic virus. These viruses hide under the guise of altered forms and carefully avoid detection. They do this because of the large number of constantly changing clones. Resident virus. This beau aims to damage your RAM, files, and motherboard memory; more than that, it will not let you delete it. Yes, that's right, once you find and try to eliminate it, it can still store it inside your OS. Boot sector virus. This type of virus extends to your device using a USB drive, CD, and floppy disk to go through your hash sector, which is responsible for your operating system and damages your device. Direct action virus.This virus differs because it is the easiest to create and can spread quickly. It joins many EXE or COM files, then removes itself.