Azure Audit Logs: BitLocker Key Read Activity

Alerts on Azure audit events reading BitLocker keys, which can enable recovery and encryption bypass.

FreeReviewedSigma · Medium · v5

Product: azure
Service: auditlogs
Author: Michael Epping, '@mepples21' (SigmaHQ), DRL 1.1
Published: 2022-06-28
Updated: 2026-07-31

ATT&CK techniques

Initial Access → Defense Evasion

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags events where BitLocker keys are read in Azure audit logs (Category KeyManagement, OperationName Read BitLocker key). Attackers may use key retrieval to enable or facilitate access to encrypted data and systems as part of privilege escalation or persistence. The detection relies on Azure audit log telemetry that records the specific key-management read operation.

Reporting behind it

Related detections9 linkedT1078.004 — drag to rearrange

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Azure Audit Logs: BitLocker Key Read Activity

Pivot detection · T1078.004 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

azure-audit-logs-bitlocker-key-retrieval-via-read-bitlocker-key-a0413867

title: "Azure Audit Logs: BitLocker Key Read Activity"
id: 61c4b97d-8565-4d3d-b01f-4f9bdf042a7e
status: test
description: This rule flags events where BitLocker keys are read in Azure audit logs (Category KeyManagement, OperationName Read BitLocker key). Attackers may use key retrieval to enable or facilitate access to encrypted data and systems as part of privilege escalation or persistence. The detection relies on Azure audit log telemetry that records the specific key-management read operation.
references:
  - https://learn.microsoft.com/en-us/entra/architecture/security-operations-devices#bitlocker-key-retrieval
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/audit_logs/azure_ad_bitlocker_key_retrieval.yml
author: Michael Epping, '@mepples21', Huntrule Team
date: 2022-06-28
tags:
  - attack.privilege-escalation
  - attack.persistence
  - attack.initial-access
  - attack.stealth
  - attack.t1078.004
logsource:
  product: azure
  service: auditlogs
detection:
  selection:
    Category: KeyManagement
    OperationName: Read BitLocker key
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: a0413867-daf3-43dd-9245-734b3a787942
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL