Researchers at Unit 42 disclosed three attack paths against Google Password Manager's passkey implementation in Chrome, with the most severe allowing malware running as a standard user to hijack passkey-protected accounts without triggering biometric prompts or screen notifications.
The three techniques, named Pass-ta-key, Silver Pass-ta-key, and Golden Pass-ta-key, target how Chrome stores and manages passkeys in the cloud authenticator component. The strongest variant, Golden Pass-ta-key, directly targets the master encryption key protecting passkey material.
An attacker exploiting these vulnerabilities needs only standard user-level privileges on a Windows machine. Once malware gains this access, it can extract the necessary cryptographic material from Google Password Manager's storage and authenticate to passkey-protected services without the victim knowing. No biometric verification, PIN entry, or visible sign-in attempt occurs on the compromised device.
This represents a fundamental bypass of passkey security. Passkeys replace passwords with cryptographic credentials and are designed to prevent account takeover even when malware compromises a device. The attack works because passkeys stored in cloud authenticators like Google's maintain the underlying decryption keys accessible to local processes. An attacker with code execution can intercept these keys before passkey authentication occurs.
The vulnerability affects Chrome and any service relying on Google Password Manager's passkey authenticator. Users storing high-value account credentials in passkeys face elevated risk if their machines become infected with malware capable of user-level code execution. This includes banking, email, and other sensitive accounts increasingly protected by passkeys instead of passwords.
Google's passkey implementation offers better security than password managers in threat models where attackers lack device access. However, Unit 42's research shows that against local malware, the security advantage narrows considerably. The attack requires neither zero-days nor sophisticated exploits, just straightforward access