Linux File Creation of /etc/nsswitch.conf in Non-Standard Paths

Flags creation of /etc/nsswitch.conf in non-standard locations that could support privilege escalation.

FreeReviewedSigma · High · v5

Product: linux
Category: file_event
Author: Swachchhanda Shrawn Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2025-10-02
Updated: 2026-07-31

ATT&CK techniques

Priv Esc

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1068Exploitation for Privilege Escalation
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags file creation or modification events where the target filename ends with /etc/nsswitch.conf, excluding common legitimate locations. Attackers may leverage non-standard placements of this configuration to influence library loading behavior within a chroot used by sudo. The detection relies on Linux file event telemetry that includes the target filename/path and supports checking for the presence or absence of known benign directories.

Reporting behind it

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Linux File Creation of /etc/nsswitch.conf in Non-Standard Paths

Pivot detection · T1068 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
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.

linux-alert-on-nsswitch-conf-creation-outside-standard-paths-10ac0730

title: Linux File Creation of /etc/nsswitch.conf in Non-Standard Paths
id: 1f06a049-8ff6-45ec-bff8-7b16f153f6b5
status: experimental
description: This rule flags file creation or modification events where the target filename ends with /etc/nsswitch.conf, excluding common legitimate locations. Attackers may leverage non-standard placements of this configuration to influence library loading behavior within a chroot used by sudo. The detection relies on Linux file event telemetry that includes the target filename/path and supports checking for the presence or absence of known benign directories.
references:
  - https://github.com/kh4sh3i/CVE-2025-32463/blob/81bb430f84fa2089224733c3ed4bfa434c197ad4/exploit.sh
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2025/Exploits/CVE-2025-32463/file_event_lnx_exploit_cve_2025_32463.yml
author: Swachchhanda Shrawn Poudel (Nextron Systems), Huntrule Team
date: 2025-10-02
modified: 2026-03-31
tags:
  - attack.privilege-escalation
  - attack.t1068
  - cve.2025-32463
  - detection.emerging-threats
logsource:
  category: file_event
  product: linux
detection:
  selection:
    TargetFilename|endswith: /etc/nsswitch.conf
  filter_main_legitimate_path:
    TargetFilename:
      - /etc/nsswitch.conf
      - /usr/share/factory/etc/nsswitch.conf
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Backup locations
level: high
license: DRL-1.1
related:
  - id: 10ac0730-c24e-4f4c-81f8-b13a1ac95a1d
    type: derived

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