Amazon SSM Agent

Amazon SSM Agent lets administrators send AWS Systems Manager requests to Windows machines and receive execution status and details. It applies software updates, management actions, and configuration changes to Amazon EC2 instances, edge devices, on-premises servers, and virtual machines, supporting remote administration across AWS and hybrid or multicloud environments.

The agent receives instructions from Systems Manager and reports results through the Amazon Message Gateway Service (ssmmessages). In AWS Regions launched before 2024, it may also send status and execution information through the Amazon Message Delivery Service (ec2messages). Operations teams use it to manage distributed servers and other managed resources without handling each machine locally.

AWS publishes the x64 Windows agent, and it is preinstalled by default on AWS-provided Windows Server AMIs. Supported images include Windows Server 2012 R2 AMIs published from November 2016 onward, plus Windows Server 2016, 2019, 2022 excluding Nano versions, and 2025. Windows Server AMIs published before November 2016 use EC2Config to process requests, while non-EC2 machines in hybrid and multicloud environments require SSM Agent to be installed and configured for Systems Manager.

The current release is version 3.3.5226.0, released as open-source software by Amazon Web Services. It fixes Windows session command parsing by removing shlex and addresses shell injection in Windows domain-join plugin parameters. AWS updates the agent as Systems Manager tools change or new capabilities are added, so older versions may be unable to use some features and are commonly kept current through automated update processes.