I regularly see this error in the Windows Error Log on one of my EC2 instances:

Certificate for local system with Thumbprint aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa is about to expire or already expired.

It appears EC2 uses a self-signed certificate to communicate with an Active Directory service somewhere on the EC2 network. It uses the certificate above to communicate with this, and tries to auto-renew periodically. It appears this mechanism has failed.

  1. What problems can arise from this?

  2. How do I fix this?

I attempted to follow the instructions here: http://technet.microsoft.com/en-us/library/cc774595(WS.10).aspx

But the certificate is not found - the Thumbprint is either an MD5 or more typically SHA1 hash. I searched for both criteria in mmc/Certificates and none were found.

How do I resolve this, and how problematic is it?

  • Dumb question: is the aa aa aa what you are actually seeing, or have you changed it to all A's just for this question? – MGOwen Jun 7 '16 at 1:41
  • Changed to aa... for the question rather than give away the thumbprint, on the off-chance posting it makes me easier to attack. – Chris Moschini Jun 7 '16 at 16:53

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