Pass-ta-key: Malware Can Hijack Your Google Passkeys. But It Has to Be on Your PC First

Researchers at Palo Alto Networks’ Unit 42 have disclosed three attacks against passkeys synced through Google Password Manager. They were reported to Google before publication. The headlines are alarming, and the underlying research is serious.

But there is a sentence in the disclosure that changes how you should read all of it, and most coverage buries it: all three attacks require malware to already be running on the victim’s computer, and none of them break the cryptography passkeys are built on.

That is not a detail. It moves the entire problem from “are passkeys safe?” to “is my machine clean?”, which is the question this site exists for.

The three attacks, briefly

They share a mechanism. Malware on an already-compromised Windows machine extracts the identity key and then uses standard Windows cryptography APIs to sign authentication requests exactly the way Chrome would. Nothing is cracked; the attacker simply borrows a trust relationship that was already established on that PC.

• Pass-ta-key takes over an account protected by a Google-synced passkey. No privilege escalation, no device unlock, no interaction from you.
• Silver Pass-ta-key deceives Google’s cloud authenticator into believing you unlocked the device with biometrics. The account is taken over without your device being used in the authentication at all.
• Golden Pass-ta-key is the worst of the three: it extracts all your synced passkeys, in a form that can be shared or sold on credential markets.

The names follow the pattern of Kerberos “silver ticket” and “golden ticket” attacks, and for the same reason: one gets you into an account, the other gets you the keyring.

Why this is a malware story, not a passkey story

It is tempting to conclude that passkeys were oversold. That is the wrong lesson, and it is worth being precise about why.

Passkeys were designed to defeat phishing and credential reuse, and they still do. An attacker who tricks you on a fake login page gets nothing, because the passkey will not sign for the wrong domain. That property is untouched by this research.

What these attacks exploit is a different assumption: that the device holding the credential is trustworthy. Once malware runs with your user account, it inherits a great deal of what you can do. That has always been true. It was true of session cookies, of saved browser passwords, of authenticator apps. Passkeys raised the bar considerably; they did not make an infected PC safe.

The honest framing: a compromised machine is a compromised machine. Any credential that lives on it, in any format, is within reach of software running as you.

What to actually do

The response is not to abandon passkeys. It is to treat the prerequisite seriously.

Make sure nothing is already running. These attacks are downstream of an infostealer or similar malware. If you have any reason to suspect an infection, unexplained slowdowns, browser settings that changed themselves, security tools that stopped working, a clean scan comes before anything else. Our guides on removing malware from Windows and telling whether your computer has a virus cover that.

Keep the browser and OS updated. Google was notified and the weaknesses are in how Chrome and the cloud authenticator handle device trust, onboarding, recovery and synced credentials. Fixes land in updates you have to actually install.

Keep a hardware security key for the accounts that matter most. A passkey bound to a physical device cannot be extracted by software, because the private key never leaves the key. That is the one design that this class of attack does not reach.

The bottom line

Three real attacks, responsibly disclosed, against a real weakness in how synced passkeys handle device trust. And a precondition that the coverage keeps underselling: the attacker has to already be on your PC.

If they are, this is one of many things they can do to you. Which is why the useful reaction to this news is not to distrust passkeys, but to make sure the machine underneath them is clean.

Sources

• Palo Alto Networks Unit 42, “Pass the Passkey: A Novel Attack Surface in Passwordless Authentication”, reported by BleepingComputer, August 2026.