PUM.Optional.LowRiskFileTypes is Malwarebytes’ detection name for a potentially unwanted modification (PUM) in the Windows registry where the system is allowed to see attached files of certain types on Microsoft Outlook as low risk, thus, enabling users to open or execute them without warning. In turn, the “Open File Security Warning” window does not pop up.
The following registry key and entry are added:
Malwarebytes deletes the created registry key without user interaction.
Also, we advise users to do a full system scan as PUM.Optional.LowRiskFileTypes modifications could have been done by malware or PUP.
When a Potentially Unwanted Modification (PUM) is detected on your computer, Malwarebytes for Windows does not know whether 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 by design.
To have Malwarebytes for Windows ignore a PUM, you must add the PUM to the Allow list. Here’s how to do it.