Computer virus

Computer viruses were software programs used to infect computers for various reasons, usually malicious. The Ninth Doctor gave Mickey Smith a computer virus that would erase all evidence of his existence from the Internet. (TV: World War Three)

RUFFCUT was a particularily malignant virus that masqueraded as enticing files to download after learning the target user's file-downloading habits, which, when downloaded would releases a "catastrophic payload". Its presence slowed the whole Internet down, and on 10 March 2005, UNIT released a press briefing about the virus, and, even within just the preceding hour, and shut down multiple government systems, a hospital, and the traffic system in Lisbon. (PROSE: Computer Virus File Sharing Alert)

A Bad Wolf virus at some point erased all information on Rose Tyler from the Torchwood database. (TV: Love & Monsters)

Cyberterrorists developed the Armageddon virus to bring down the international banking network, and the virus was later used by Alan Jackson to reprogram Mr Smith. (TV: The Lost Boy)

In Leadworth, 2008, the Eleventh Doctor wrote a computer virus on a mobile phone. It caused all computers and networks around the world to reset their counters and display only the number zero, to alert the Atraxi of Prisoner Zero's presence. It was also, according to the Doctor, "a tiny bit alive". (TV: The Eleventh Hour)

In 2009 Ian Webster created the locust virus to take control over his former bullies. The Umorgus wanted to use the virus to take control over the whole world. The virus was destroyed by Sarah Jane Smith and her friends. (AUDIO: Deadly Download)

In 2000 a computer virus was released by the Cybermen which destroyed all the vowels in Earth's computer systems. (PROSE: Vrs) This virus was eradicated by P.R.O.B.E. as the other organisations, such as the groups from Geneva and Canary Wharf, were, by Louise Bayliss's knowledge, were "nowhere to be seen". (PROSE: The Last Dose)

Utnapishtim created a computer virus to destroy Qataka, but did not have time to perfect it and it only broke her links with her mind-slaves. After learning she had survived, he used a perfected version against her, but she had already safeguarded herself and was only temporarily immobilised. (PROSE: Timewyrm: Genesys)

After being revived in the Dalek-Movellan War, Davros created a computer virus that targeted the First Movellan, it spreading throughout the Movellan network to all aboard the Prime Ship. The Tenth Doctor forced the Prime Ship to reboot however, cutting it off from the larger network long enough for the First to purge the virus. Inspired, the Movellans developed their own virus to target the Dalek mutant directly. (AUDIO: The Triumph of Davros)