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Description

This search looks for AWS CloudTrail events from Amazon Security Lake where a user is making successful API calls to view/update/delete the existing password policy in an AWS organization. It is unlikely for a regular user to conduct this operation. These events may potentially be malicious, adversaries often use this information to gain more understanding of the password defenses in place and exploit them to increase their attack surface when a user account is compromised.

  • Type: Hunting

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2023-05-22
  • Author: Patrick Bareiss, Splunk
  • ID: 5ade5937-11a2-4363-ba6b-39a3ee8d5b1a

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1201 Password Policy Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`amazon_security_lake` "api.service.name"="iam.amazonaws.com" "api.operation" IN ("UpdateAccountPasswordPolicy","GetAccountPasswordPolicy","DeleteAccountPasswordPolicy") "api.response.error"=null 
| stats count min(_time) as firstTime max(_time) as lastTime by identity.user.account_uid identity.user.credential_uid identity.user.name identity.user.type identity.user.uid identity.user.uuid http_request.user_agent src_endpoint.ip cloud.region 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `asl_aws_password_policy_changes_filter`

Macros

The SPL above uses the following Macros:

:information_source: asl_aws_password_policy_changes_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • api.service.name
  • api.operation
  • identity.user.account_uid
  • identity.user.credential_uid
  • identity.user.name
  • identity.user.type
  • identity.user.uid
  • identity.user.uuid
  • http_request.user_agent
  • src_endpoint.ip

How To Implement

You must install Splunk Add-On for AWS Version v7.0.0 (https://splunkbase.splunk.com/app/1876) that includes includes a merge of all the capabilities of the Splunk Add-on for Amazon Security Lake. This search works with Amazon Security Lake logs which are parsed in the Open Cybersecurity Schema Framework (OCSF)format.

Known False Positives

While this search has no known false positives, it is possible that an AWS admin has legitimately triggered an AWS audit tool activity which may trigger this event.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
72.0 90 80 User $identity.user.name$ is attempting to $api.operation$ the password policy for accounts

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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

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