This is the detection of potentially unwanted modifications (PUMs) on the registry that disable the affected system’s Task Manager. In effect, this prevents the user from terminating programs that may be causing problems on their systems, such as malware.
The following registry value data are modified:
Malwarebytes can modify these registry value data back to their Windows default settings without user interaction.
Also, we advise users to do a full system scan as PUM.Optional.DisableTaskMgr could have been added to the system by malware or PUP.