This is a new virus that is found in December 2008 and announce by Symantec on 09-01-09 and now it widely spading all over the world and make all the computer no network connection. This virus monitors DNS requests to domains containing certain strings and blocks access to those domains so that it will appear that the network request timed out.When trying to enter to another computer over the network , windows will alert that ” No network provider ….” but we still can ping the computer name or IP Address.
W32.Downadup.B creates an autorun.inf file on all mapped drives so that the threat automatically executes when the drive is accessed. The threat then monitors for drives that are connected to the compromised computer in order to create an autorun.inf file as soon as the drive becomes accessible.
So now what to do with it is :
1- Download the removal tool from Symantec website and place it on your desktop.
2- Download the Security patch from microsoft website. ( Choose the file support with your OS).
3- Temporarily Disable System Restore (Windows Me/XP).
5-Update the virus definitions (Symantec).
5- Reboot computer in SafeMode
6-Run the FixDownadup.exe that u just downloaded and let it scan until it found a viruses.
7-Run the Security patch.
8-Reboot your system in normal mode and run the Full System Scan to make sure that no virus present on your computer.
Hope you can solves this problem as me also. For me I spend nearly 1 week until I found the right solution to do that.