Most reports by anti-virus programs and user reviews have identified the bac.exe file as malware. It is a worm that is associated with the malware called W32.Bactera or bactera worm. The location of this process file is in C:\. Known sizes for this file include 73,728 bytes and 53,248 bytes with 50% occurrence. It does not have a visible window. It is a non-system file on Windows. Bactera worm tries to spread itself through file sharing networks. Among the known systems to be infected by the worm include Windows 95, 98, ME, NT, 2000, XP and Server 2003. This worm displays fake error messages telling that “MFClibrary.dll” file cannot be found. It is actually a trick to make the user believe that it is a key generator/cracktool. The bacteria worm creates files such as C:\bac.exe, C:\bac2.exe, C:\AntiVirScan.exe and C:\list. It will look for the presence of file sharing application called eMule to create the folder C:\Windows\Temp\Bactera. It will copy itself to this folder more than 1,500 times by using filenames from predefined database. It will create a registry subkey for storing information pertaining to the threat installation that is HKEY_CURRENT_USER\Software\VB and VBA Program Settings\Bactera.

Most non-system processes that are running can be stopped because they are not involved in running your operating system. bac.exe. is used by W32.Bactera or Bactera Worm, If you shut down bac.exe, it will likely start again at a later time either after you restart your computer or after an application start. To stop bac.exe, permanently you need to uninstall the application that runs this process which in this case is W32.Bactera or Bactera Worm, from your system.

After uninstalling applications it is a good idea to scan you Windows registry for any left over traces of applications. Registry Reviver by ReviverSoft is a great tool for doing this.

The ReviverSoft experts have not yet reviewed bac.exe

A process usually a part of an installed application such as W32.Bactera or Bactera Worm, or your operating system that is responsible for running in functions of that application. Some application require that they have processes running all the time so they can do things such as check for updates or notify you when you get an instant message. Some poorly written applications have many processes that run that may not be required and take up valuable processing power within your computer.

We have not received any complaint about this process having higher than normal impact on PC performance. If you have had bad experiences with it please let us know in a comment below and we will investigate it further.

The first thing you should do if bac.exe. is causing errors on your computer is to run a Windows registry scan with Registry Reviver If you are still seeing errors after this you should uninstall the program that bac.exe, belongs to, in this case W32.Bactera or Bactera Worm