Potential Notepad++ CVE-2025-49144 Exploitation

experimentalhigh
log source: windows · process_creationauthor Swachchhanda Shrawan Poudel (Nextron Systems)date 2025-06-26
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description

What this is, in brief.

Detects potential exploitation of CVE-2025-49144, a local privilege escalation vulnerability in Notepad++ installers (v8.8.1 and prior) where the installer calls regsvr32.exe without specifying the full path. This allows an attacker to execute arbitrary code with elevated privileges by placing a malicious regsvr32.exe alongside this Legitimate Notepad++ installer. The vulnerability is triggered when the installer attempts to register the NppShell.dll file, which is a component of Notepad++.

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tags

attack.persistenceattack.privilege-escalationattack.executionattack.stealthattack.t1574.008cve.2025-49144detection.emerging-threats
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rule source (YAML)

title: Potential Notepad++ CVE-2025-49144 Exploitation
id: 933f0bb5-0681-4fe7-8a17-4e6cccbaac44
status: experimental
description: |
    Detects potential exploitation of CVE-2025-49144, a local privilege escalation vulnerability in Notepad++ installers (v8.8.1 and prior) where the installer calls regsvr32.exe without specifying the full path.
    This allows an attacker to execute arbitrary code with elevated privileges by placing a malicious regsvr32.exe alongside this Legitimate Notepad++ installer.
    The vulnerability is triggered when the installer attempts to register the NppShell.dll file, which is a component of Notepad++.
references:
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-49144
    - https://x.com/NullSecurityX/status/1937444064867029179
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-06-26
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.008
    - cve.2025-49144
    - detection.emerging-threats
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        Image|endswith: '\regsvr32.exe'
        CommandLine|startswith: 'regsvr32 /s'
        CommandLine|contains: '\contextMenu\NppShell.dll'
    filter_main_legit_regsvr32:
        Image:
            - 'C:\Windows\System32\regsvr32.exe'
            - 'C:\Windows\SysWOW64\regsvr32.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high
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detects techniques (1)

ATT&CK techniques this enables or maps to.

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references

External citations — patches, advisories, analysis.