Editing Malware (section)

====Virus====
{{Main|Computer virus}}
[[File:Kuku virus for MS-DOS.png|thumb|Output of the MS-DOS "Kuku" virus]]
A computer virus is software usually hidden within another seemingly harmless program that can produce copies of itself and insert them into other programs or files, and that usually performs a harmful action (such as destroying data).<ref>{{cite web|title=What are viruses, worms, and Trojan horses?|url=https://kb.iu.edu/d/aehm|access-date=23 February 2015|website=Indiana University|publisher=The Trustees of Indiana University|archive-date=4 September 2016|archive-url=https://web.archive.org/web/20160904162213/https://kb.iu.edu/d/aehm|url-status=live}}</ref> They have been likened to [[Virus|biological viruses]].<ref name=":1" /> An example of this is a portable execution infection, a technique, usually used to spread malware, that inserts extra data or [[executable code]] into [[Portable Executable|PE files]].<ref name="Szor2005">{{cite book|author=Peter Szor|url=https://books.google.com/books?id=XE-ddYF6uhYC&pg=PT204|title=The Art of Computer Virus Research and Defense|date=3 February 2005|publisher=Pearson Education|isbn=978-0-672-33390-3|page=204}}</ref> A computer virus is software that embeds itself in some other [[executable]] software (including the operating system itself) on the target system without the user's knowledge and consent and when it is run, the virus is spread to other executable files.