Nimda


Nimda is a malicious file infecting computer worm. It quickly spread, surpassing the economic damage caused by previous outbreaks such as Code Red.
The first released advisory about this thread was released on September 18, 2001. Due to the release date, exactly one week after the attacks on the World Trade Center and Pentagon, some media quickly began speculating a link between the virus and Al Qaeda, though this theory ended up proving unfounded.
Nimda affected both user workstations running Windows 95, 98, NT, 2000 or XP and servers running Windows NT and 2000.
The worm's name origin comes from the reversed spelling of "admin".
F-Secure found the text "Concept Virus V.5, Copyright2001 R.P.China" in the Nimda code, suggesting its country of origin.

Methods of infection

Nimda was so effective partially because it—unlike other infamous malware like Code Red—uses five different infection vectors: