AWS IAM Virtual MFA Device Registration Attempt with Session Token

Last updated 2 months ago on 2025-11-03

Created 9 months ago on 2025-04-11

About

Detects attempts to create or enable a Virtual MFA device (CreateVirtualMFADevice, EnableMFADevice) using temporary AWS credentials (access keys beginning with ASIA). Session credentials are short-lived and tied to existing authenticated sessions, so using them to register or enable MFA devices is unusual. Adversaries who compromise temporary credentials may abuse this behavior to establish persistence by attaching new MFA devices to maintain access to high-privilege accounts despite key rotation or password resets.

Tags

Domain: CloudData Source: AWSData Source: Amazon Web ServicesData Source: AWS CloudTrailData Source: AWS IAMTactic: PersistenceUse Case: Identity and Access AuditLanguage: eql

Severity

medium

Risk Score

MITRE ATT&CK™

Persistence (TA0003)(external, opens in a new tab or window)

↳ Account Manipulation (T1098)(external, opens in a new tab or window)

↳ Modify Authentication Process (T1556)(external, opens in a new tab or window)

False Positive Examples

Some legitimate administrative workflows or CI/CD automation pipelines may temporarily configure or re-enable MFA devices using session-based credentials. Validate the calling identity’s purpose, source IP, and user agent to confirm whether this activity was authorized. Additionally, when a user creates or enables a Virtual MFA device through the AWS Management Console, the underlying CloudTrail event will also show a temporary credential (access key ID beginning with ASIA), because the console itself issues short-lived STS session credentials for every logged-in user. These events are expected and should not be considered suspicious.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: filebeat-*logs-aws.cloudtrail-*
Related Integrations: aws(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗iam where event.dataset == "aws.cloudtrail"
  and event.provider == "iam.amazonaws.com"
  and event.outcome == "success"
  and event.action in ("CreateVirtualMFADevice", "EnableMFADevice")
  and startsWith (aws.cloudtrail.user_identity.access_key_id, "ASIA")

Install detection rules in Elastic Security

Detect AWS IAM Virtual MFA Device Registration Attempt with Session Token in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).