You should review deploy keys to ensure that there aren't any unauthorized (or possibly compromised) keys. You can also approve existing deploy keys that are valid.

  1. On GitHub, navigate to the main page of the repository.

  2. Under your repository name, click Settings. Repository settings button

  3. In the left sidebar, click Deploy keys. Deploy keys setting

  4. On the Deploy keys page, take note of the deploy keys associated with your account. For those that you don't recognize, or that are out-of-date, click Delete. If there are valid deploy keys you'd like to keep, click Approve. Deploy key list

For more information on managing deploy keys, check out our guide on deploy keys.