Presentation on theme: "Virus Code Actions Clara Pirie & Eilidh Currie. Viruses A virus is a computer program that can copy itself and infect a computer without the permission."— Presentation transcript:
Viruses A virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the user. Viruses can increase their chances of spreading to other computers by infecting files on a network file system.
Replication In order to replicate itself, a virus must be permitted to execute code and write to memory. A simple virus will normally check if a file has been infected, if it hasn’t it will infect it then save the changes to the executable file. After closing the file, the finder will find new files for the replicator to infect.
Camouflaging Camouflage viruses attempt to appear as a benign program and then pounce and infect your computer. A Trojan horse is an example of a camouflage virus. Often email attachments are camouflage viruses, as people open them without realising the danger in them.
Watching A virus can lie and wait or WATCH for a particular action or date before it is activated. The longer the time before activation the greater the number of computer systems that will be potentially infected. A virus which watches for a date is known as a TIME BOMB, and a virus which watches for an action is known as a LOGIC BOMB.
Delivery The delivery of a virus is the method which it uses in order to enter a computer system and cause the infection. Viruses are spread in seconds over computer networks and in some cases security flaws in the operating system.
WARNING!!! If you receive a message from an unknown email address – DO NOT OPEN!! DELETE IT IMMEDIATELY!!!! This applies even more to emails with attachments. You have been warned.