Windows esentutl.exe Browser Data Collection via -r and WebCache path

Flags esentutl.exe runs with -r and WebCache references, indicating potential browser data collection.

FreeReviewedSigma · Medium · v2

Product: windows
Category: process_creation
Author: frack113 (SigmaHQ), DRL 1.1
Published: 2022-02-13
Updated: 2026-07-31

ATT&CK techniques

Collection

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
- T1005Data from Local System
C2
Exfiltration
Impact

What it detects

This rule flags process executions of esentutl.exe where the command line includes the -r switch and references the Windows WebCache directory. Attackers can use esentutl.exe to extract or collect browser-related information from Internet Explorer and Microsoft Edge. Detection relies on Windows process creation telemetry, including the process image name, original file name, and full command line arguments.

Reporting behind it

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Windows esentutl.exe Browser Data Collection via -r and WebCache path

Pivot detection · T1005 · 9 related

Changelog

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.

windows-detect-esentutl-exe-usage-to-collect-browser-cache-data-6a69f62d

title: Windows esentutl.exe Browser Data Collection via -r and WebCache path
id: de5604a4-30b5-426d-9d08-ccb153463232
status: test
description: This rule flags process executions of esentutl.exe where the command line includes the -r switch and references the Windows WebCache directory. Attackers can use esentutl.exe to extract or collect browser-related information from Internet Explorer and Microsoft Edge. Detection relies on Windows process creation telemetry, including the process image name, original file name, and full command line arguments.
references:
  - https://thedfirreport.com/2022/02/07/qbot-likes-to-move-it-move-it/
  - https://redcanary.com/threat-detection-report/threats/qbot/
  - https://thedfirreport.com/2022/10/31/follina-exploit-leads-to-domain-compromise/
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_esentutl_webcache.yml
author: frack113, Huntrule Team
date: 2022-02-13
modified: 2024-03-05
tags:
  - attack.collection
  - attack.t1005
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    - Image|endswith: \esentutl.exe
    - OriginalFileName: esentutl.exe
  selection_flag:
    CommandLine|contains|windash: -r
  selection_webcache:
    CommandLine|contains: \Windows\WebCache
  condition: all of selection*
falsepositives:
  - Legitimate use
level: medium
license: DRL-1.1
related:
  - id: 6a69f62d-ce75-4b57-8dce-6351eb55b362
    type: derived

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