i did research and i found this
Antimalware Service Executable is a background-running service in Windows Defender that scans for malware and spyware when you access them. It is also known as MsMpEng.exe and appears in Task Manager. It is a part of the Microsoft Defender antivirus included with Windows. The program runs in the background and scans your computer for threats such as harmful software, viruses, worms, and so on.