Adversaries may acquire user credentials from third-party password managers. Password managers are applications designed to store user credentials, normally in an encrypted database. Credentials are typically accessible after a user provides a master password that unlocks the database. After the database is unlocked, these credentials may be copied to memory. These databases can be stored as files on disk.
Adversaries may acquire user credentials from password managers by extracting the master password and/or plain-text credentials from memory. Adversaries may extract credentials from memory via Exploitation for Credential Access. Adversaries may also try brute forcing via Password Guessing to obtain the master password of a password manager.
Refer to NIST guidelines when creating password policies for master passwords.
Consider re-locking password managers after a short timeout to limit the time plaintext credentials live in memory from decrypted databases.
Update password managers regularly by employing patch management for internal enterprise endpoints and servers.
Monitor executed commands and arguments that may acquire user credentials from third-party password managers. 
Monitor file reads that may acquire user credentials from third-party password managers.
|OS API Execution
Monitor for API calls that may search for common password storage locations to obtain user credentials.
Monitor process being accessed that may acquire user credentials from third-party password managers.