AWS Bedrock Delete Knowledge Base

name: AWS Bedrock Delete Knowledge Base
id: 8b4e3d62-f743-11ee-9f6e-acde48001123
version: 6
creation_date: '2025-03-25'
modification_date: '2026-05-13'
author: Bhavin Patel, Splunk
status: production
type: TTP
description: The following analytic identifies attempts to delete AWS Bedrock Knowledge Bases, which are resources that store and manage domain-specific information for AI models. It monitors AWS CloudTrail logs for DeleteKnowledgeBase API calls. This activity could indicate an adversary attempting to remove knowledge bases after compromising credentials, potentially to disrupt business operations or remove traces of data access. Deleting knowledge bases could impact model performance, remove critical business context, or be part of a larger attack to degrade AI capabilities. If confirmed malicious, this could represent a deliberate attempt to cause service disruption or data loss.
data_source:
    - AWS CloudTrail DeleteKnowledgeBase
search: >-
    `cloudtrail` eventSource=bedrock.amazonaws.com eventName=DeleteKnowledgeBase
    | rename user_name as user
    | stats count min(_time) as firstTime max(_time) as lastTime values(requestParameters.knowledgeBaseId) as knowledgeBaseIds by src user user_agent vendor_account vendor_product dest signature vendor_region
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `aws_bedrock_delete_knowledge_base_filter`
how_to_implement: The Splunk AWS Add-on is required to utilize this data. The search requires AWS CloudTrail logs with Bedrock service events enabled. You must install and configure the AWS App for Splunk (version 6.0.0 or later) and Splunk Add-on for AWS (version 5.1.0 or later) to collect CloudTrail logs from AWS. Ensure the CloudTrail is capturing Bedrock Knowledge Base management events.
known_false_positives: Legitimate administrators may delete Knowledge Bases as part of normal operations, such as when replacing outdated knowledge bases, removing test resources, or consolidating information. Consider implementing an allowlist for expected administrators who regularly manage Knowledge Base configurations.
references:
    - https://www.sumologic.com/blog/defenders-guide-to-aws-bedrock/
    - https://attack.mitre.org/techniques/T1562/
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: User $user$ deleted AWS Bedrock Knowledge Base $knowledgeBaseIds$ from $src$
    entity:
        field: user
        type: user
        score: 50
threat_objects:
    - field: src
      type: ip_address
analytic_story:
    - AWS Bedrock Security
asset_type: AWS Account
mitre_attack_id:
    - T1485
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1485/aws_delete_knowledge_base/cloudtrail.json
          sourcetype: aws:cloudtrail
          source: aws_cloudtrail
      test_type: unit