The Conficker virus is a computer virus which targets the WIndows Operating System. The conficker virus was first detected in November 2008. Conficker uses combination of malware techniques to infect end users pc. Conficker Virus is also know as  Downup,Downadup and kido. Many analyst believe this to be the biggest computer virus infection since 2003.

The first variant of conficker was discovered late 2008 which propagated through the internet by exploiting a vulnerability in a network service. The vulnerability was found on the following windows OS : windows 2000,windows xp , windows vista, windows server 2003, windows server 2008 and R2.  Microsoft sent out a emergency patch on October 23, 2008 which closed the vulnerability this was before the warth of conficker was released on the world.The Conficker Worm had a payload which suppose to activate on 1st April 2009 however nothing occured on this day. The conficker worm has infested hospitals,police and many other services

Different Variants of the conficker virus were released and they performed different malicious things in the background of the infected pc.  Variants ABCE  exploit the Server service on PCs which turn already infected computer to uses the RPC request to force a buffer overflow and excute shellcode on the target PC. On the affected PC the worms a HTTP server on a port which can vary between 1024 and 10000 the target shellcode connects back to the Infected HTTP SERVER PC and downloads the worm. Variant D spreads via usbs and removable devices.

•Win32/Conficker.A was reported to Microsoft on November 21, 2008.

•Win32/Conficker.B was reported to Microsoft on December 29, 2008.

•Win32/Conficker.C was reported to Microsoft on February 20, 2009

•Win32/Conficker.D was reported to Microsoft on March 4, 2009.

•Win32/Conficker.E was reported to Microsoft on April 8, 2009.