Potential Entra ID PRT Extraction via BrowserCore

Last updated a day ago on 2026-09-04
Created a day ago on 2026-09-04

About

Identifies anomalous execution of BrowserCore.exe, the Windows component used by Chromium-based browsers for native messaging with the Web Account Manager (WAM). Adversaries abuse BrowserCore to extract Entra ID Primary Refresh Tokens (PRTs) without interactive browser context, enabling session hijacking. Legitimate BrowserCore launches carry a chrome-extension:// argument from the browser native-messaging host.
Tags
Domain: EndpointOS: WindowsPlatform: WindowsUse Case: Threat DetectionTactic: Credential AccessRule Type: ESQLData Source: Elastic DefendData Source: SysmonData Source: Windows Security Event LogsData Source: CrowdstrikeData Source: SentinelOneData Source: Microsoft Defender XDRLanguage: esql
Severity
high
Risk Score
73
MITRE ATT&CK™

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

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

Definition

Integration Pack
Prebuilt Security Detection Rules
Related Integrations

endpoint(external, opens in a new tab or window)

windows(external, opens in a new tab or window)

system(external, opens in a new tab or window)

crowdstrike(external, opens in a new tab or window)

sentinel_one_cloud_funnel(external, opens in a new tab or window)

m365_defender(external, opens in a new tab or window)

Query
text code block:
from logs-endpoint.events.process-*, logs-windows.sysmon_operational-*, logs-system.security-*, logs-windows.*, winlogbeat-*, logs-crowdstrike.fdr*, logs-sentinel_one_cloud_funnel.*, logs-m365_defender.event-* metadata _id, _version, _index | where KQL(""" event.category : "process" and event.type : "start" and host.os.type : "windows" """) and to_lower(process.name) == "browsercore.exe" and process.parent.name is not null and process.command_line is not null and not to_lower(process.command_line) like "*chrome-extension://*" | keep @timestamp, _id, _version, _index, data_stream.namespace, host.id, host.name, user.name, user.id, process.entity_id, process.name, process.executable, process.command_line, process.pe.original_file_name, process.parent.name, process.parent.executable, process.parent.command_line

Install detection rules in Elastic Security

Detect Potential Entra ID PRT Extraction via BrowserCore 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).