Millions of Windows-based personal computers worldwide, including thousands in China and India, have been affected by a family of network worms which goes by the name Conficker (also called Kido or Downadup).
Relevant URL(s):
http://www.microsoft.com/technet/security/Bulletin/MS08-067.mspx
http://www.us-cert.gov/current/index.html#conficker_worm_information
Solution:
Install the Microsoft Windows Patch MS08-067(KB958644).
How to check if your system is updated with Patch:
Note : Please ensure that your system Microsoft Windows Patch MS08-067(KB958644) is updated on your system. Please execute the following to check if your system is having these updates.
On Windows XP system Go to Control Panel -> Add/ Remove programs à select Show updates check box ,you will find the Security update for windows as shown below Picture 1.
On Windows Vista system Go to Control Panel -> Programs and Features -> Installed updates, You will find the security update for Windows as shown in below Picture 2.
Picture 1 ( Windows XP )

Picture 2 ( Windows Vista )

How to check if your system is infected:
The presence of a Conficker infection may be detected if you are unable to navigate to the following websites:
http://www.symantec.com/norton/theme.jsp?themeid=conficker_worm&inid=us_ghp+link_conficker_worm
http://www.mcafee.com
If you are unable to reach either of these websites, the Conficker infection may be indicated (the most current variant of Conficker interferes with queries for these sites, preventing a user from visiting them).
