msdef.exe is a process which is registered as the Trojan.W32.Secefa trojan. It takes advantage of the Windows LSASS vulnerability, which creates a buffer overflow and instigates your computer to shut down.
To see more information about this vulnerability please look at the following Microsoft bulletin: http://www.microsoft.com/technet/security/bulletin/ms04-011.mspx.
This process is a security risk and should be removed from your system.
Other instances of MSDEF.EXE:
1) msdef.exe is a process which is registered as a trojan. This Trojan allows attackers to access your computer from remote locations, stealing passwords, Internet banking and personal data. This process is a security risk and should be removed from your system.
Warning: Multiple instances of MSDEF may be running on your pc at one time. Some of these may or may not be the legitimate versions.
If you are asking yourself if it is safe to remove msdef.exe from your Windows system then it is understandable that it is causing trouble. msdef.exe is not a critical component and a non-system process. Any process that is not managed by the system is known as non-system processes. It is safe to terminate the non-system process as they do not affect the general functionality of the operating system. However, the program using the non-system processes will be either terminated or halted.
There are many reasons why you are seeing msdef.exe error in your Windows system including:
Application conflicts and Missing or corrupt windows drivers can also lead to msdef.exe error.
The solution to fixing msdef.exe error include any one of the following
It is also recommended that you run a performance scan to automatically optimize memory and CPU settings.
Windows process requires three resource types to function properly including CPU, Memory, and Network. CPU cycles to do computational tasks, memory to store information and network to communicate with the required services. If any of the resources are not available, it will either get interrupted or stopped.
Any given process has a process identification number(PID) associated with it. A user can easily identify and track a process using its PID. Task Manager is a great way to learn how much resources msdef.exe process is allocating to itself. It showcases process resource usage in CPU/Memory/Disk and Network. If you have a GPU, it will also showcase the percentage of GPU it is using to run the process.