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Detection rules › Sigma

AWS ElastiCache Security Group Modified or Deleted

Status
test
Severity
low
Log source
product aws, service cloudtrail
Author
Austin Songer @austinsonger
Source
github.com/SigmaHQ/sigma

Identifies when an ElastiCache security group has been modified or deleted.

Known false positives

  • A ElastiCache security group deletion may be done by a system or network administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment. Security Group deletions from unfamiliar users or hosts should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

MITRE ATT&CK coverage

TacticTechniques
Impact

Telemetry coverage

PlatformRecord / event type
AWSCloudTrail event AuthorizeCacheSecurityGroupIngress: Grants ingress network access to a cache security group for the specified EC2 security group.
AWSCloudTrail event DeleteCacheSecurityGroup: Deletes an existing cache security group, provided no clusters are currently associated with it.
AWSCloudTrail event RevokeCacheSecurityGroupIngress: Removes a previously authorized ingress rule from a cache security group for the specified EC2 security group.

Rule body

title: AWS ElastiCache Security Group Modified or Deleted
id: 7c797da2-9cf2-4523-ba64-33b06339f0cc
status: test
description: Identifies when an ElastiCache security group has been modified or deleted.
references:
    - https://github.com/elastic/detection-rules/blob/7d5efd68603f42be5e125b5a6a503b2ef3ac0f4e/rules/integrations/aws/impact_elasticache_security_group_modified_or_deleted.toml
author: Austin Songer @austinsonger
date: 2021-07-24
modified: 2022-10-09
tags:
    - attack.impact
    - attack.t1531
logsource:
    product: aws
    service: cloudtrail
detection:
    selection:
        eventSource: elasticache.amazonaws.com
        eventName:
            - 'DeleteCacheSecurityGroup'
            - 'AuthorizeCacheSecurityGroupIngress'
            - 'RevokeCacheSecurityGroupIngress'
            - 'AuthorizeCacheSecurityGroupEgress'
            - 'RevokeCacheSecurityGroupEgress'
    condition: selection
falsepositives:
    - A ElastiCache security group deletion may be done by a system or network administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment. Security Group deletions from unfamiliar users or hosts should be investigated. If known behavior is causing false positives, it can be exempted from the rule.


level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    eventSource: elasticache.amazonaws.com
    eventName:
        - 'DeleteCacheSecurityGroup'
        - 'AuthorizeCacheSecurityGroupIngress'
        - 'RevokeCacheSecurityGroupIngress'
        - 'AuthorizeCacheSecurityGroupEgress'
        - 'RevokeCacheSecurityGroupEgress'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
eventNameeq
  • AuthorizeCacheSecurityGroupEgress
  • AuthorizeCacheSecurityGroupIngress
  • DeleteCacheSecurityGroup
  • RevokeCacheSecurityGroupEgress
  • RevokeCacheSecurityGroupIngress
field:"aws::eventName" kind:eq
eventSourceeq
  • elasticache.amazonaws.com
field:"aws::eventSource" kind:eq value:"elasticache.amazonaws.com"