Windows Process Creation: svchost Running NavShExt.dll Deletion/Setting Commands

Alerts on svchost.exe process commands referencing cached NavShExt.dll deletion and execution markers consistent with Elise backdoor activity.

FreeReviewedSigma · Critical · v5
Product
windows
Category
process_creation
Author
Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2018-01-31
Updated
2026-07-31
title: "Windows Process Creation: svchost Running NavShExt.dll Deletion/Setting Commands"
id: d1bacdb2-3f1b-4c44-87dc-67d259d2a8dd
status: test
description: This rule flags Windows process creation events where svchost.exe is launched with command-line activity referencing NavShExt.dll in a Roaming Caches path. It looks for either a command that deletes NavShExt.dll via a cache-related path, or command-line usage that contains the string ',Setting' associated with NavShExt.dll. These behaviors matter because they can indicate execution and cleanup steps used by malicious backdoors, and the rule relies on process creation telemetry including Image and CommandLine fields.
references:
  - https://community.rsa.com/community/products/netwitness/blog/2018/02/13/lotus-blossom-continues-asean-targeting
  - https://web.archive.org/web/20200302083912/https://www.accenture.com/t20180127T003755Z_w_/us-en/_acnmedia/PDF-46/Accenture-Security-Dragonfish-Threat-Analysis.pdf
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2018/Malware/Elise-Backdoor/proc_creation_win_malware_elise.yml
author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2018-01-31
modified: 2023-03-09
tags:
  - attack.g0030
  - attack.g0050
  - attack.s0081
  - attack.execution
  - attack.t1059.003
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection_other_svchost:
    Image|endswith: \Microsoft\Network\svchost.exe
  selection_other_del:
    CommandLine|contains|all:
      - \Windows\Caches\NavShExt.dll
      - /c del
  selection_dll_path:
    CommandLine|endswith:
      - \AppData\Roaming\MICROS~1\Windows\Caches\NavShExt.dll
      - \AppData\Roaming\Microsoft\Windows\Caches\NavShExt.dll
  selection_dll_function:
    CommandLine|contains: ",Setting"
  condition: 1 of selection_other_* or all of selection_dll_*
falsepositives:
  - Unlikely
level: critical
license: DRL-1.1
related:
  - id: e507feb7-5f73-4ef6-a970-91bb6f6d744f
    type: derived