PUM.Optional.HijackExefiles is Malwarebytes’ detection name for a potentially unwanted modification that changes the default association of files with an .exe extension. This usually results in users being unable to run any programs.
The following registry value data are modified:
the default value is changed.
Malwarebytes can modify this registry value data back to its Windows default setting without user interaction.
When a PUM is detected on your computer, Malwarebytes for Windows does not know if it was authorized. Optimization software, malware, and Potentially Unwanted Programs (PUPs) are known to make these types of changes, hence they are regarded as potentially unwanted.
To have Malwarebytes for Windows ignore a PUM, you must add the PUM as an exclusion.
When a PUM is excluded, Malwarebytes for Windows does not detect the PUM during scans or Real-Time Protection.