All popular browsers allow users to store sensitive data such as credentials for online and cloud services (such as social networks, email providers, and banking) and forms data (e.g. Credit card number, address, phone number) In Windows environment, most browsers (and many other applications) choose to protect these secrets by using Window Data Protection API (DPAPI), which provides an easy method to encrypt and decrypt secret data. Lately, Mimikatz, a popular pentest/hacking tool, was updated to include a functionality that allows highly-privileged attackers to decrypt all of DPAPI secrets. In this talk, I will analyze the Mimikatz Anti-DPAPI attack targeting the Domain Controller (DC) which puts all DPAPI secrets in peril and show how it can be defeated with network monitoring.