This detection rule aims to identify potentially malicious activities related to the AWS System Manager by monitoring CloudTrail logs for specific event patterns. When a command is successfully executed against an EC2 instance using the `SendCommand` event from `ssm.amazonaws.com`, it triggers an alert. The condition requires that the `eventName` is `SendCommand`, the `eventSource` is `ssm.amazonaws.com`, and the command's execution status is `Success`. This indicates that a command has been issued and executed successfully, which could represent an unauthorized or otherwise suspicious interaction with an instance. Given that legitimate uses of System Manager exist, it is crucial to analyze the context of the events to filter false positives, as there are many scenarios where users could be performing legitimate maintenance or updates via System Manager.