Viruses & Malware
What is malware? Mal icious soft ware . - A software program designed to cause harm to a computer without the knowledge of the user.
Types of malware Computer viruses
Worms
Trojan horses
Spyware
Adware
Any other type of malicious & unwanted software.
What is a computer virus? A computer program that can infect a computer and replicate and spread without the users knowledge.
Types of viruses Resident
Direct Action
Overwrite
Boot
Macro
Directory Polymorphic
File Infectors
Companion
Fat
Logic Bombs
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 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.

Virus&malware