Detection rules › Sigma
Kubernetes Admission Controller Modification
Detects when a modification (create, update or replace) action is taken that affects mutating or validating webhook configurations, as they can be used by an adversary to achieve persistence or exfiltrate access credentials.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1078 Valid Accounts |
| Persistence | T1078 Valid Accounts |
| Privilege Escalation | T1078 Valid Accounts |
| Stealth | T1078 Valid Accounts |
| Credential Access | T1552.007 Unsecured Credentials: Container API |
Event coverage
Rules detecting the same action
Other rules on this platform that filter on the same API call or operation.
Rule body yaml
title: Kubernetes Admission Controller Modification
id: eed82177-38f5-4299-8a76-098d50d225ab
related:
- id: 6ad91e31-53df-4826-bd27-0166171c8040
type: similar
status: test
description: |
Detects when a modification (create, update or replace) action is taken that affects mutating or validating webhook configurations, as they can be used by an adversary to achieve persistence or exfiltrate access credentials.
references:
- https://kubernetes.io/docs/reference/config-api/apiserver-audit.v1/
- https://security.padok.fr/en/blog/kubernetes-webhook-attackers
author: kelnage
date: 2024-07-11
tags:
- attack.privilege-escalation
- attack.initial-access
- attack.persistence
- attack.stealth
- attack.t1078
- attack.credential-access
- attack.t1552
- attack.t1552.007
logsource:
product: kubernetes
service: audit
detection:
selection:
objectRef.apiGroup: 'admissionregistration.k8s.io'
objectRef.resource:
- 'mutatingwebhookconfigurations'
- 'validatingwebhookconfigurations'
verb:
- 'create'
- 'delete'
- 'patch'
- 'replace'
- 'update'
condition: selection
falsepositives:
- Modifying the Kubernetes Admission Controller may need to be done by a system administrator.
- Automated processes may need to take these actions and may need to be filtered.
level: medium
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
objectRef.apiGroup: 'admissionregistration.k8s.io'
objectRef.resource:
- 'mutatingwebhookconfigurations'
- 'validatingwebhookconfigurations'
verb:
- 'create'
- 'delete'
- 'patch'
- 'replace'
- 'update'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
objectRef.apiGroup | eq |
|
objectRef.resource | eq |
|
verb | eq |
|