Reverse engineering and decrypting CyberArk vault credential files

This blog post details a technical deep-dive into CyberArk credential (.cred) files, explaining the custom key generation and AES encryption scheme used to protect stored vault passwords. The author reverse-engineered CreateCredFile.exe to demonstrate how, by default, the file includes enough data (an “AdditionalInformation” field) to derive the AES key and decrypt credentials; a Python tool to perform decryption is provided. Mitigations include using DPAPI-protected storage for credential secrets and applying the vendor update that changes the crypto implementation.