As referenced in the github page you linked:
Allows for the extraction of KeePass 2.X key material from memory, as
well as the backdooring and enumeration of the KeePass trigger system.
Towards the bottom of the page:
The KeeThief.ps1 PowerShell file contains Get-KeePassDatabaseKey,
which loads/executes the KeeTheft assembly in memory to extract
KeePass material from an KeePass.exe process with an open database.
The KeePassConfig.ps1 file contains method to enumerate KeePass config
files on a system (Find-KeePassconfig), retrieve the set triggers for
a KeePass.config.xml file (Get-KeePassConfigTrigger), add malicious
KeePass triggers (Add-KeePassConfigTrigger), and remove KeePass
triggers (Remove-KeePassConfigTrigger).
This idea of taking the password of a KeyPass database is not new. This utility fits the purpose of removing the protection around the active process when it is in an "unlocked" mode (commonly sitting idle before timeout, or in active use).