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