Spontaneous shutdowns in AWS EC2 instance

I have hosted a web server in an EC2 instance running Windows Server 2012 R2, and suddenly the instance became not available. I ran into the issue couple of times and when I checked the AWS Console, status of the instance has changed to Stop.

Interestingly when I checked for system logs in Event Viewer, I found this error message.

The process C:\Program Files\Amazon\XenTools\LiteAgent.exe (EC2AMAZ-******) has initiated the shutdown of computer EC2AMAZ-****** on behalf of user NT AUTHORITY\SYSTEM for the following reason: No title for this reason could be found Reason Code: 0x8000000c Shutdown Type: shutdown Comment:

Any idea why it happened and what does LiteAgent.exe do?

This is Amazon's management service. This is the message you would get if someone shuts the machine down via the Web UI or if Amazon's infrastructure shut the machine down (for autoscaling etc).

If you need to know who's doing this you should consider enabling AWS Cloud Trail on the EC2 instances.