AWS CloudShell Environment Created
Description
Identifies the creation of a new AWS CloudShell environment. CloudShell is a browser-based shell that provides command-line access to AWS resources directly from the AWS Management Console. The CreateEnvironment API is called when a user launches CloudShell for the first time or when accessing CloudShell in a new AWS region. Adversaries with console access may use CloudShell to execute commands, install tools, or interact with AWS services without needing local CLI credentials. Monitoring environment creation helps detect unauthorized CloudShell usage from compromised console sessions.
Query · kuery
data_stream.dataset: "aws.cloudtrail"
and event.provider: "cloudshell.amazonaws.com"
and event.action: "CreateEnvironment"
and event.outcome: "success"
Investigation fields
Pivot points the source recommends for triage.
@timestampuser.nameuser_agent.originalsource.ipaws.cloudtrail.user_identity.arnaws.cloudtrail.user_identity.typeaws.cloudtrail.user_identity.access_key_idevent.actionevent.outcomecloud.account.idcloud.regionaws.cloudtrail.request_parametersaws.cloudtrail.response_elements
Known false positives
- Legitimate use of CloudShell by administrators for routine AWS management tasks. Verify whether the user has a legitimate need for CloudShell access and correlate with recent console login activity. Environment creation also occurs when users access CloudShell in a new AWS region.
Analyst notes
Investigating AWS CloudShell Environment Created
AWS CloudShell is a browser-based shell environment that provides instant command-line access to AWS resources without requiring local CLI installation or credential configuration. While this is convenient for legitimate administrators, it also provides adversaries with a powerful tool if they gain access to a compromised AWS console session.
This rule detects when a CloudShell environment is created via the CreateEnvironment API. This event occurs when a user launches CloudShell for the first time or when accessing CloudShell in a new AWS region (each region maintains a separate environment).
Possible investigation steps
- Identify the actor
- Review
aws.cloudtrail.user_identity.arnoruser.nameto determine which IAM principal created the CloudShell environment. - Check
aws.cloudtrail.user_identity.typeto identify whether this is an IAM user or an assumed role session. -
Verify if this user typically performs command-line or administrative operations.
-
Analyze the source context
- Review
source.ipandsource.geofields to verify the request origin matches expected administrator locations. - Check
user_agent.originalto confirm the request came from a browser session. -
Look for the preceding
ConsoleLoginevent to understand how the session was established. -
Correlate with surrounding activity
- Look for any IAM operations (CreateAccessKey, CreateUser, AttachRolePolicy) that occurred after CloudShell was accessed.
-
Check for data exfiltration patterns or reconnaissance activity from the same session.
-
Assess the broader context
- Determine if this user has a legitimate need for CloudShell access based on their role.
- Review recent access patterns for the console session that initiated CloudShell.
- Check if MFA was used for the console login.
False positive analysis
- Administrators routinely using CloudShell for AWS management tasks will trigger this rule. Consider tuning for known admin users if noise is a concern.
- Users accessing CloudShell in a new AWS region will generate a
CreateEnvironmentevent even if they have used CloudShell before in other regions. - Training or certification activities may involve CloudShell environment creation.
Response and remediation
- If unauthorized, immediately terminate the console session to revoke CloudShell access.
- Review and revoke any credentials or resources created during the CloudShell session.
- Consider restricting CloudShell access via SCPs or IAM policies for sensitive accounts or users who do not require it.
- Implement session duration limits to reduce the window of opportunity for console session abuse.
- Enable MFA for all console logins to reduce the risk of session compromise.