hl2.exe is missing in garrys mod

hi, i have been having problems with my garrys mod, my hl2.exe is gone from the garrys mod file. i have attempted to fix this but nothing has worked, please help

Use “Verify Integrity of Game Cache” in gmod’s properties in steam

Probably some Anti-Virus that deleted the file. Doing what B!N4RY said should fix the issue