The addon "Install Translator" with Pass: 123 from http://translatorforfirefox.blogspot.com/ is a password stealer PWS:Win32/Stealer.H!bit and creates the following folder and file.
file: C:\Users\MyPc\AppData\Roaming\amd64_microsoft-windows-videodiagnostic\puiapi.exe
This .exe is dangerous and records user passwords.
Microsoft Defender Report:
password stealer PWS:Win32/Stealer.H!bit