Resident Virus A virus that takes up permanent residence in the RAM memory. It can take over or interupt any operation executed by the computer system. It can corrupt files and programs; such as copy, open, close, rename and more. Examples: Randex, CMJ, Meve, and MrKlunky.
Direct Action Virus A batch file that resides in the root directory of the hard disk. When executed it will infect files in the directory that it is in, plus any directed to, in the batch file AUTOEXEC.BAT file PATH.
Overwrite Virus A virus that deletes of overwrites part or all of the information in a file, making them partially or totally worthless. To get rid of the virus, the file has to be deleted. Examples of this virus include: Way, Trj.Reboot, Trivial.88.D.
Boot Virus A virus that affects the boot sector of the hard drive or a floppy drive. The boot sector gives the computer information on how to boot, if it is not functioning the computer won't boot. To avoid a boot virus, don't boot your computer with an unknown floppy disk in your floppy drive and make sure it is write protected. Examples of boot viruses include: Polyboot.B, AntiEXE.
Macro Virus A virus written in a macro language that infects the files that were created with it. When the file is opened the macro virus runs automatically. This may arrive on your computer by email attachment. Examples of macro viruses: Relax, Melissa.A, Bablas, O97M/Y2K.
Directory Virus <ul><li>Directory viruses will replace an existing executable and move the real file somewhere else, so when you run it you are unknowingly running the virus program instead of the original. It then becomes impossible to find the original file. </li></ul>
Polymorphic Virus Viruses that encode or encrypt themselves so that each new version is different. This enables them to replicate and very hard for virus scanners to track down.
File Infectors The majority of viruses are file infectors. This virus is activated by running an executable file like .exe or .com extension files. Once run, the virus does its damage according to the program in the executable file.
Companion Virus once the system is infected they accompany the files that already exist. They can lay in wait or take action immediately. Some examples include: Stator, Asimov.1539, and Terrax.1069
Fat Virus this virus will only infect a computer running a file allocation table (FAT) file system. This virus will prevent access to parts of the hard drive preventing files to be accessed Newer windows computers use NTFS and don't need to worry about this virus.
Logic Bomb <ul><li>Not technically a virus because it does not replicate. It is program designed to destroy data, or perform a function, that is set to go off under specific conditions. </li></ul>
What is a worm? A worm typically infects networked computers. It replicates but may not corrupt files. It uses a network to send copies of itself to other nodes without user intervention. It will at the very least slow the computers and network down.
What is a trojan? Trojan – refers to the story of the Trojan horse. This is malware that is hidden inside of a benign looking function but actually performs a malicious function. This malware may allow unauthorized access to the computer, give them access to the files and control the computer.
What is spyware? Spyware is computer software that is secretly installed on your computer to monitor your internet usage and behavior.
Spyware continued Spyware – spyware can do more than monitor the user's behavior. It can collect personal information, such as, surfing habits and sites visited. Spyware can also install software and redirirect web browser activity. Spyware can slow connection speeds and set different home pages
List of fake anti-spyware <ul><li>AntiVirus 360