GitHub Security Breach – Hackers Stole Code Signing Certificates

GitHub announced that it suffered a security breach in which unauthorized individuals obtained access to specific development and release planning repositories and stole encrypted code-signing certificates for the Desktop and Atom applications.

Hence, in order to avoid any potential misunderstandings, the company has made the decision to revoke the certificates exposed to public scrutiny.

There will be a limitation to the functionality of GitHub Desktop for Mac and Atom when these certificates are revoked.

Detection of Activity

GitHub confirmed that it has not yet found any evidence of malicious use of the password-protected certificates, and also assured that they are currently investigating further possibilities.


There was a cloning incident that occurred on December 6, 2022, affecting GitHub’s atom, desktop, and other deprecated Github-owned organizations. The cloning was carried out using a compromised Personal Access Token (PAT) linked to a machine account.

While GitHub detected this unauthorized access on December 7, 2022. It has been determined that GitHub[.]com’s services were not at risk after a thorough investigation.

While GitHub also concluded that all these projects were even not altered by unauthorized individuals in any way. 

Invalidated Versions

On February 2, 2023, the following versions of GitHub Desktop for Mac will stop working:-

  • 3.1.2
  • 3.1.1
  • 3.1.0
  • 3.0.8
  • 3.0.7
  • 3.0.6
  • 3.0.5
  • 3.0.4
  • 3.0.3
  • 3.0.2

However, GitHub Desktop for Windows will not be affected by this change. While in the case of Atom, on February 2, 2023, the following versions will stop working:-

GitHub confirmed that the repositories impacted in the security incident did not contain any customer information. The company promptly revoked the compromised credentials. 

However, the method by which the Personal Access Token was breached remains undisclosed by GitHub. It’s important to note that if the certificates were decrypted, an attacker could potentially use them to sign malicious software and present it as if it were from GitHub.

Compromised Certificates

In total there are three certificates were compromised by the threat actors, and on February 2, 2023, all three certificates will be revoked by GitHub.

Here below we have mentioned them:-

  • Two Digicert code signing certificates used for Windows
  • One Apple Developer ID certificate

A revoked certificate will prevent all versions of the apps signed with these compromised certificates from functioning in the future.

To avoid disruption to your workflow, GitHub highly recommends you update Desktop and/or downgrade Atom before February 2 to ensure a smooth transition.

In order for GitHub to remain the most trusted and secure developer platform on the planet, GitHub bears the utmost importance to security and trustworthiness.

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