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The file System Defender.dll is a part of Fake Antiviral software.
You must delete the file System Defender.dll immediately!
Delete the file System Defender.dll without delay!
Kill the process System Defender.dll and remove System Defender.dll from Windows startup.
System Defender.dll Information and Removal:
System Defender.dll is Trojan/Backdoor.
Kill the file System Defender.dll and remove System Defender.dll from Windows startup.