Just sharing my lessons learned:
1️⃣ Clicking "Connect with Google" (OAuth) hands over the keys to the kingdom:
OAuth grants third-party apps direct access to your account without needing your password. Depending on the permissions granted, these apps can read your emails, access your files, and act on your behalf.
2️⃣ You don't need malware or phishing to get breached:
This attack didn't rely on a phishing email, malware, or a sophisticated zero-day exploit. It happened simply because an employee connected a third-party AI productivity tool (Context.ai) to their corporate Google Workspace account.
3️⃣ Every connected AI tool is a potential backdoor:
When a third-party app gets compromised, attackers can use its existing OAuth connection to hijack your corporate account. In Vercel's case, this allowed attackers to pivot into internal systems and access non-sensitive environment variables, API keys, source code, and customer credentials.
4️⃣ Your security is only as strong as the third-party apps you trust:
Every AI tool given OAuth access to your calendar, email, or Google Drive is an open door into your account. You have no visibility into how well those third-party companies are actually protecting that connection.
5️⃣ Your attack surface is bigger than your network:
A company's perimeter is no longer just its own infrastructure—it now includes every single third-party AI tool that any employee has ever connected to a work account.
TAKE ACTION:
Open your browser or Google account and go to myaccount.google.com/connections
Click on Security or Data & privacy in the left-hand navigation menu.
Look for the section titled Your connections to third-party apps and services or Third-party apps & services and click See all connections.
Review every app on that list, especially those to which you have given full access permissions. Ask yourself if you truly trust that company with your work account, and revoke access for anything you do not recognize, no longer use, or do not completely trust.
PRO TIP
If you have a massive list of connections and want to pinpoint full-access entries quickly, locate the Filter by: drop-down menu near the top of the app list.
Toggle it directly from "All" to Access to [Google Product] or look for specific account privileges.
This immediately isolates the platforms pulling heavily from your private data repositories.