Changes

#Automatic replication: When an infected program is run, the virus also runs, searching the host computer for other programs to infect.  

#Automatic replication: When an infected program is run, the virus also runs, searching the host computer for other programs to infect.  

#By email: viruses (and other kinds of malware) are often transmitted as email attachments. In some cases, scripts within a message can also be used to infect a device, if the E-mail client program is not configured to ignore scripts.  

#By email: viruses (and other kinds of malware) are often transmitted as email attachments. In some cases, scripts within a message can also be used to infect a device, if the E-mail client program is not configured to ignore scripts.  

#Misleading software: A "[[Trojan Horse (malware)|Trojan Horse]]" is a program which seems useful, but contains a virus (or other malware).  The main program may or not perform as advertised, but the distributor knows it is infected. A Trojan Horse carried virus typically does not replicate itself but is spread when the user copies the program.  In some cases, legitimate software may also be infected after release.  Even though the software by itself is legitimate and safe, infected copies can be distributed to attack unsuspecting users.  

#Misleading software: A "[[Trojan Horse (malware)|Trojan Horse]]" is a program which seems useful, but contains a virus (or other malware).  The main program may or not perform as advertised, but the distributor knows it is infected. A Trojan Horse carried virus typically does not replicate itself but is spread when the user copies the program.  In some cases, legitimate software may also be infected after release.  Even though the software by itself is legitimate and safe, infected copies can be distributed to attack unsuspecting users.<ref name="MS What is virus">http://www.microsoft.com/en-us/safety/pc-security/virus-whatis.aspx</ref>

#Instant messaging: A direct computer-to-computer link required for instant messaging can be misused to deliver a virus.

#Instant messaging: A direct computer-to-computer link required for instant messaging can be misused to deliver a virus.<ref name="MS What is virus">http://www.microsoft.com/en-us/safety/pc-security/virus-whatis.aspx</ref>

==Anti-virus tactics==

==Anti-virus tactics==

==Terminology==

==Terminology==

Discussion of the virus problem is sometimes hampered by the terminology used by purists, who distinguish between such varieties as "[[Computer worm|worm]]", "[[Trojan Horse]]", etc. but a common term for unwanted software that infects computers is "virus". A more technically correct term is "[[malware]]."

Discussion of the virus problem is sometimes hampered by the terminology used by purists, who distinguish between such varieties as "[[Computer worm|worm]]", "[[Trojan Horse]]", etc. but a common term for unwanted software that infects computers is "virus". A more technically correct term is "[[malware]]."

==External links==

==External links==

*[http://www.howstuffworks.com/virus.htm "How Computer Viruses Work"]

*[http://www.howstuffworks.com/virus.htm "How Computer Viruses Work"]

[[Category:Software]]

[[Category:Malware]]