ID | Technique | Tactic |
---|---|---|
T1586 | Compromise Accounts | Resource Development |
T1586.003 | Cloud Accounts | Resource Development |
T1621 | Multi-Factor Authentication Request Generation | Credential Access |
T1556 | Modify Authentication Process | Credential Access |
T1556.006 | Multi-Factor Authentication | Defense Evasion |
Detection: AWS Multi-Factor Authentication Disabled
Description
The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages AWS CloudTrail logs to identify events where MFA devices are deleted or deactivated. This activity is significant because disabling MFA can indicate an adversary attempting to weaken account security, potentially to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, posing a significant risk to the security and integrity of the cloud infrastructure.
Search
1`cloudtrail` (eventName= DeleteVirtualMFADevice OR eventName=DeactivateMFADevice)
2| stats count min(_time) as firstTime max(_time) as lastTime by src eventName eventSource aws_account_id userAgent eventID awsRegion user_name userIdentity.arn status
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)`
5| `aws_multi_factor_authentication_disabled_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
AWS CloudTrail DeactivateMFADevice | AWS | 'aws:cloudtrail' |
'aws_cloudtrail' |
AWS CloudTrail DeleteVirtualMFADevice | AWS | 'aws:cloudtrail' |
'aws_cloudtrail' |
Macros Used
Name | Value |
---|---|
cloudtrail | sourcetype=aws:cloudtrail |
aws_multi_factor_authentication_disabled_filter | search * |
aws_multi_factor_authentication_disabled_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
The Splunk AWS Add-on is required to utilize this data. The search requires AWS CloudTrail logs.
Known False Positives
AWS Administrators may disable MFA but it is highly unlikely for this event to occur without prior notice to the company
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
User $user_name$ has disabled Multi-Factor authentication for AWS account $aws_account_id$ | 64 | 80 | 80 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
Integration | ✅ Passing | Dataset | aws_cloudtrail |
aws:cloudtrail |
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 3