Mimikatz is a well-known hacktool used to extract Windows passwords in plain-text from memory, perform pass-the-hash attacks, inject code into remote processes, generate golden tickets, and more. This tool is used by red teams and real threat actors alike due to its powerful toolset and open-source nature allowing for easy modification. This tool is still regularly maintained and kept up to date with latest changes in Windows. Mimikatz is often delivered and executed without writing to disk (fileless) in an attempt to avoid detection. 

Microsoft Defender Antivirus detects and removes this threat.

Hacktools can be used to patch or "crack" some software so it will run without a valid license or genuine product key.

We recommend you don't run hacktools because they can be associated with malware or potentially unwanted software.

We often see malware on PCs where hacktools are detected. You can read more about hacktools in Volume 13 of the Security Intelligence Report.