Azure Service Principal Sign-In Followed by Arc Cluster Credential Access

Last updated 8 days ago on 2026-03-10

Created 8 days ago on 2026-03-10

About

Detects when a service principal authenticates to Microsoft Entra ID and then lists credentials for an Azure Arc-connected Kubernetes cluster within a short time window. The `listClusterUserCredential` action retrieves tokens that enable kubectl access through the Arc Cluster Connect proxy. This sequence (service principal sign-in followed by Arc credential retrieval), represents the exact attack chain used by adversaries with stolen service principal secrets to establish a proxy tunnel into Kubernetes clusters. Service principals that authenticate externally (as opposed to managed identities) and immediately access Arc cluster credentials warrant investigation, particularly when the sign-in originates from an unexpected location or ASN.

Tags

Domain: CloudDomain: IdentityData Source: AzureData Source: Azure ArcData Source: Microsoft Entra IDData Source: Microsoft Entra ID Sign-In LogsUse Case: Threat DetectionTactic: Credential AccessTactic: Initial AccessLanguage: eql

Severity

medium

Risk Score

MITRE ATT&CK™

Credential Access (TA0006)(external, opens in a new tab or window)

↳ Unsecured Credentials (T1552)(external, opens in a new tab or window)

Initial Access (TA0001)(external, opens in a new tab or window)

↳ Valid Accounts (T1078)(external, opens in a new tab or window)

False Positive Examples

CI/CD pipelines that authenticate as a service principal and then access Arc clusters as part of deployment workflows will trigger this rule. Identify and exclude known automation service principal app IDs. Administrators using service principal credentials to manage Arc-connected clusters during maintenance windows may trigger this rule. Correlate with change management records.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-azure.signinlogs-*logs-azure.activitylogs-*
Related Integrations: azure(external, opens in a new tab or window)
Query

✄𐘗text code block:
✄𐘗sequence with maxspan=30m
[authentication where event.dataset == "azure.signinlogs"
    and azure.signinlogs.category == "ServicePrincipalSignInLogs"
    and azure.signinlogs.properties.status.error_code == 0
] by azure.signinlogs.properties.app_id
[any where event.dataset == "azure.activitylogs"
    and azure.activitylogs.operation_name : "MICROSOFT.KUBERNETES/CONNECTEDCLUSTERS/LISTCLUSTERUSERCREDENTIAL/ACTION"
    and event.outcome : ("Success", "success")
] by azure.activitylogs.identity.claims.appid

Install detection rules in Elastic Security

Detect Azure Service Principal Sign-In Followed by Arc Cluster Credential Access in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).