Last week, attackers broke into Northflank, a cloud platform developers use to run their apps, and went straight for the keys its customers had stored there. Within hours, some of those keys were being used by someone else. If you juggle several calendars, this is worth five minutes of your time, because your connected calendar apps hold keys too: the ones that open your work, client and personal calendars.
What happened at Northflank and the other platforms
On 30 October, Northflank told every customer to assume all their stored environment variables had been decrypted and to rotate every secret: AI provider keys, cloud credentials, payment keys and database passwords. Before the day was out, users reported that AI API keys they had stored on the platform had already been used without their permission. Northflank revoked access tokens, sessions and integrations, so customers had to sign in again and reconnect everything.
It wasn’t a one-off. Nine days earlier, Railway, another hosting platform, disclosed that an attacker may have reached customer environment variables and, for some of them, their decrypted contents. It paused new deployments and asked customers to rotate their keys, and it linked the incident to a series of attacks targeting AI providers, BleepingComputer reported. The same day as Northflank, Chainalysis disclosed that an outside actor had used “offensive agentic techniques” to get into its systems and exposed customer names, email addresses and role labels.
The pattern is clear. Attackers aren’t only picking locks one person at a time any more. They go after the places where many people’s keys are kept together, and they increasingly use AI agents to do the legwork.
Why connected calendar apps are a target
Every scheduling tool, calendar app, browser extension and AI assistant you have connected to Google Calendar or Microsoft 365 holds a token: a key that lets it read (and often change) your calendar without asking you again. Connect five tools to three calendars and that’s fifteen keys, kept by companies you have probably forgotten about.
For a consultant or freelancer, a calendar is far from boring. It holds client names, attendee lists, meeting links, phone numbers and the occasional note that was never meant to leave the room. If a tool that copies full event details between your calendars is breached, every one of those details is exposed, for every client.
Here’s what we’d do this week:
- Review your connected calendar apps. For Google accounts, open Third-party apps and services. For personal Microsoft accounts, open app access; for work accounts, ask your IT team.
- Remove anything you no longer use. An old scheduling trial still holding a key to your client’s calendar is pure risk and no benefit.
- Prefer tools that keep less. The fewer copies of your event details that exist, the less there is to steal.
- Connect AI assistants through sign-in and consent, not pasted keys. A key pasted into a config file lives forever. A short-lived token from a consent screen expires on its own and can be withdrawn.
That last point matters more every month. Agents are taking over the clicking and form-filling we used to do by hand, and they will book, move and decline meetings for you. How they get into your calendars is now as important as what they do there.
Where Calendrz fits
We built Calendrz around keeping as little of your calendar as possible. Availability mirroring reads when you’re busy in one calendar and auto-blocks that time in the others, with no titles, attendees, locations or notes copied across. When you remove a connected account from your Profile, we clean up the blocks we created in it and give up our access to it.
The same thinking runs through the Calendrz MCP server, which lets Claude and other AI assistants read and manage events across all your connected accounts. Your assistant connects through a sign-in and consent screen, its access tokens expire after an hour, and your Google and Microsoft tokens are never handed to the AI. Our rule is simple: an agent should get a key that expires, not a copy of your keyring.
No tool can promise it will never be attacked. What you can choose is how much each tool holds, and how quickly you can take a key back.
Ready to protect your time across every calendar without handing your event details around? Try Calendrz free.
