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Entra ID Device-Bound PRT Replay via First-Party App from Unusual IP

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Entra ID Device-Bound PRT Replay via First-Party App from Unusual IP

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Detects a first-party FOCI tooling client (Azure CLI, PowerShell, VS Code, Graph CLI, Azure AD PowerShell, or Visual Studio) redeeming a device-bound Primary Refresh Token (PRT) for Microsoft Graph, SharePoint/OneDrive, or Exchange Online from an IP that is not among that user and device’s Windows Sign-In or WAM addresses. Replay events are limited to compliant or Intune-managed devices: the stolen cookie keeps the workstation deviceid, so compliant-device Conditional Access can succeed off-box.

Rule type: esql

Rule indices: None

Severity: high

Risk score: 73

Runs every: 1h

Searches indices from: now-24h (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Domain: Cloud
  • Domain: Identity
  • Use Case: Threat Detection
  • Use Case: Identity and Access Audit
  • Data Source: Azure
  • Data Source: Microsoft Entra ID
  • Data Source: Microsoft Entra ID Sign-in Logs
  • Platform: Entra ID
  • Tactic: Credential Access
  • Tactic: Defense Evasion
  • Tactic: Initial Access
  • Resources: Investigation Guide
  • Rule Type: ESQL

Version: 1

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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Triage and analysis

Investigating Entra ID Device-Bound PRT Replay via First-Party App from Unusual IP

Adversaries who steal a WAM PRT SSO cookie (BrowserCore / InteractiveToken harvest) redeem it off-box for Microsoft Graph, SharePoint/OneDrive, or Exchange Online using a first-party FOCI client. PRTremote uses Azure CLI (04b07795-8ddb-461a-bbee-02f9e1bf7b46); TokenTactics and AADInternals can use Azure AD PowerShell (1b730954-1685-4b74-9bfd-dac224a7b894) or Microsoft Office (d3590ed6-52b3-4102-aeff-aad2292ab01c) when refreshing a PRT into a Graph, Outlook, or SharePoint token. This rule keys on CLI / PowerShell / VS Code / Visual Studio, not Teams, Office, OneDrive SyncEngine, Authentication Broker, Outlook Mobile, Bing, or Azure Portal — those clients routinely egress on a different IP than Windows Sign-In. Hunt Office-client PRT separately if harvest is already confirmed. The issued access token carries the workstation deviceid, so Conditional Access policies that require a compliant device can succeed even though the redeeming IP is not the device. Replay events must be is_compliant or is_managed so the join tracks a stolen enrolled workstation PRT, not an unmanaged ROADtx device.

This is not ConsentFix / OAuth-code phishing. Those flows show OAuth2:Authorize with Redirect and often lack a bound compliant device on the Graph token. Do not close this alert by following the first-party OAuth phishing playbook alone.

Possible investigation steps

  • Review azure.signinlogs.properties.user_principal_name, azure.signinlogs.properties.device_detail.device_id, and source.ip. Confirm incoming_token_type on the replay events is primaryRefreshToken and device_detail.is_compliant / is_managed are true. Esql.resource_display_name_values should be Microsoft Graph, Office 365 SharePoint Online, OneDrive for Business, and/or Office 365 Exchange Online.
  • Treat Esql.source_ip_device_values as the workstation (Windows Sign-In / Windows-AzureAD-Authentication-Provider/1.0) — the device the PRT was bound to, and the likely theft origin. Treat source.ip / Esql.source_ip_replay_values as Graph / SharePoint / Exchange PRT IPs that are not in that device-session set (the replay actor). On-box FOCI from the workstation IP is excluded from the replay set. The harvest emulation showed workstation public IP versus attacker SNAT — including Azure ASN 8075, so a Microsoft-owned ASN does not clear the alert. The stolen PRT cookie nonce is typically valid for about five minutes; that is the attacker’s redeem window, not this rule’s lookback. The workstation may have signed in hours earlier, so the query correlates 24 hours of Windows Sign-In / WAM IPs with the replay.
  • Inspect Esql.app_display_name_values and Esql.user_agent_original_values. A cookie POST through WAM can show a Trident/MSIE user agent on the Azure CLI client ID; that is the same IE stack legitimate Windows az login uses when it brokers through WAM, so it is triage context, not a detection key. TokenTactics Graph refresh commonly presents as Microsoft Office (omitted here). A follow-on python-requests/* Graph token from the same session is tooling, not the first-party binary on the workstation.
  • Hunt endpoint telemetry for the same user or device_detail.display_name as host.name: svchost.exe (Schedule) → cmd.exe → BrowserCore.exe with < / > redirection, or files formatted_nonce.txt / prt_cookie.txt.
  • Intune audit (create-clientcertificate) is enrollment context only; it will not fire on the harvest. Use it as optional join on user OID, not as coverage.
  • Review Graph, SharePoint, and mailbox activity after the replay for directory, file, or mail enumeration.

False positive analysis

  • Developers who run Azure CLI, Graph CLI, or VS Code from a different egress than Windows Sign-In while WAM still attaches the workstation deviceid. Exception known Cloud Shell / jump-host IPs after confirming the client actually ran there.
  • Microsoft Teams, Office, OneDrive SyncEngine, Authentication Broker, Outlook Mobile, Bing, Azure Portal, and Office 365 Management Graph PRT are excluded. Do not treat their absence as a miss; they are omitted because split-tunnel M365 egress is routine.
  • First sign-in of a new device can have sparse Windows Sign-In history in the 24-hour window; widen the hunt before responding.
  • Hybrid-joined workstations that report both is_compliant and is_managed as false (no Intune) will not match the replay branch. Hunt those deviceids separately if harvest is already confirmed.

Response and remediation

  • Contact the user to confirm whether they ran the first-party client in Esql.app_display_name_values from the replay IP.
  • If unauthorized, revoke refresh tokens and primary refresh tokens for the user. The deviceid on the token is often the legitimate workstation — do not delete that device as if it were a ROADtx registration until you confirm otherwise.
  • Isolate the workstation, hunt for InteractiveToken scheduled tasks and BrowserCore harvest, and treat the admin identity that registered the task as a second compromised principal.

Setup

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The Azure Fleet integration (or Filebeat Azure module) with Microsoft Entra ID sign-in logs is required. Ingest SignInLogs and NonInteractiveUserSignInLogs into logs-azure.signinlogs-* so Windows Sign-In / WAM device activity and FOCI Graph, SharePoint, and Exchange token issuance are both available for the join.

See Microsoft Entra ID sign-in logs and the Azure integration.

Rule query

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from logs-azure.signinlogs-*
// find successful sign-in events where a managed device exists
| where event.dataset == "azure.signinlogs"
    and azure.signinlogs.properties.status.error_code == 0
    and azure.signinlogs.properties.device_detail.device_id is not null

// filter for device sign-in events from Windows Sign-In or WAM (login session)
| eval Esql.is_device_session = azure.signinlogs.properties.app_display_name == "Windows Sign In"
    or user_agent.original == "Windows-AzureAD-Authentication-Provider/1.0"

// filter for tooling FOCI clients that can redeem a PRT (replay)
| eval Esql.is_prt_replay = azure.signinlogs.properties.app_id in (
        "04b07795-8ddb-461a-bbee-02f9e1bf7b46",  // Microsoft Azure CLI
        "1950a258-227b-4e31-a9cf-717495945fc2",  // Microsoft Azure PowerShell
        "aebc6443-996d-45c2-90f0-388ff96faa56",  // Visual Studio Code
        "14d82eec-204b-4c2f-b7e8-296a70dab67e",  // Microsoft Graph Command Line Tools
        "1b730954-1685-4b74-9bfd-dac224a7b894",  // Azure Active Directory PowerShell
        "872cd9fa-d31f-45e0-9eab-6e460a02d1f1"   // Visual Studio
    )

    // target resource are common adversary targets for access
    and azure.signinlogs.properties.resource_id in (
        "00000003-0000-0000-c000-000000000000",  // Microsoft Graph
        "00000003-0000-0ff1-ce00-000000000000",  // Office 365 SharePoint Online
        "6a9b9266-8161-4a7b-913a-a9eda19da220",  // OneDrive for Business
        "00000002-0000-0ff1-ce00-000000000000"   // Office 365 Exchange Online
    )
    and azure.signinlogs.properties.incoming_token_type == "primaryRefreshToken"
    and (
        azure.signinlogs.properties.device_detail.is_compliant == true
        or azure.signinlogs.properties.device_detail.is_managed == true
    )

// device session or PRT replay event have to exist
| where Esql.is_device_session or Esql.is_prt_replay

// aggregate entities for both device session and PRT replay events
// aggregate by user and device
| stats
    Esql.source_ip_device_values = values(source.ip) where Esql.is_device_session,
    Esql.source_ip_replay_values = values(source.ip) where Esql.is_prt_replay,
    Esql.event_count_replay = count(*) where Esql.is_prt_replay,
    Esql.event_count_device_session = count(*) where Esql.is_device_session,
    Esql.user_principal_name_values = values(azure.signinlogs.properties.user_principal_name),
    Esql.app_display_name_values = values(azure.signinlogs.properties.app_display_name) where Esql.is_prt_replay,
    Esql.resource_id_values = values(azure.signinlogs.properties.resource_id) where Esql.is_prt_replay,
    Esql.resource_display_name_values = values(azure.signinlogs.properties.resource_display_name) where Esql.is_prt_replay,
    Esql.device_display_name_values = values(azure.signinlogs.properties.device_detail.display_name),
    Esql.user_agent_original_values = values(user_agent.original) where Esql.is_prt_replay,
    Esql.device_is_compliant_values = values(azure.signinlogs.properties.device_detail.is_compliant) where Esql.is_prt_replay,
    Esql.device_is_managed_values = values(azure.signinlogs.properties.device_detail.is_managed) where Esql.is_prt_replay,
    Esql.authentication_requirement_values = values(azure.signinlogs.properties.authentication_requirement) where Esql.is_prt_replay,
    Esql.conditional_access_status_values = values(azure.signinlogs.properties.conditional_access_status) where Esql.is_prt_replay,
    Esql.earliest_timestamp = min(@timestamp),
    Esql.latest_timestamp = max(@timestamp)
  by azure.signinlogs.properties.user_id, azure.signinlogs.properties.device_detail.device_id

// filter for PRT replay events that have at least one replay IP
| where Esql.event_count_replay > 0
    and Esql.event_count_device_session > 0
    and Esql.source_ip_replay_values is not null
    and Esql.source_ip_device_values is not null

// expand the replay IP list and keep only IPs that are not in the device-session set
| mv_expand Esql.source_ip_replay_values
| where not mv_contains(Esql.source_ip_device_values, Esql.source_ip_replay_values)
| eval Esql.source_ip_replay = Esql.source_ip_replay_values,
       user.id = azure.signinlogs.properties.user_id,
       source.ip = Esql.source_ip_replay_values
| keep
    user.id,
    source.ip,
    azure.signinlogs.properties.user_id,
    azure.signinlogs.properties.device_detail.device_id,
    Esql.*

Framework: MITRE ATT&CKTM

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