Detectionmediumtest

Registry Modification of MS-settings Protocol Handler

Detects registry modifications to the 'ms-settings' protocol handler, which is frequently targeted for UAC bypass or persistence. Attackers can modify this registry to execute malicious code with elevated privileges by hijacking the command execution path.

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Launch

François Hubaut, Swachchhanda Shrawan Poudel (Nextron Systems)Created Mon Dec 20Updated Sat Jan 24dd3ee8cc-f751-41c9-ba53-5a32ed47e563windows

Log Source

WindowsProcess Creation

ProductWindows← raw: windows

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection_reg_img:
        - Image|endswith: '\reg.exe'
        - OriginalFileName: 'reg.exe'
    selection_pwsh_img:
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'powershell.exe'
              - 'pwsh.dll'
    selection_reg_cli:
        CommandLine|contains: 'add'
    selection_pwsh_cli:
        CommandLine|contains:
            - 'New-ItemProperty'
            - 'Set-ItemProperty'
            - 'ni '
            - 'sp '
    selection_cli_key:
        CommandLine|contains: '\ms-settings\shell\open\command'
    condition: (all of selection_reg_* or all of selection_pwsh_*) and selection_cli_key

False Positives

Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

References

MITRE ATT&CK

Tactics

TA0005 · Defense Evasion TA0004 · Privilege Escalation TA0003 · Persistence

Techniques

T1112 · Modify Registry

Sub-techniques

T1548.002 · Bypass User Account Control T1546.001 · Change Default File Association

Related Rules

SimilarDetectionhigh

Shell Open Registry Keys Manipulation

Detects the shell open key manipulation (exefile and ms-settings) used for persistence and the pattern of UAC Bypass using fodhelper.exe, computerdefaults.exe, slui.exe via registry keys (e.g. UACMe 33 or 62)

Detects similar activity. Both rules may fire on overlapping events.

Rule Metadata

Rule ID

dd3ee8cc-f751-41c9-ba53-5a32ed47e563

Status

test

Level

medium

Type

Detection

Created

Mon Dec 20

Modified

Sat Jan 24

Author

François Hubaut, Swachchhanda Shrawan Poudel (Nextron Systems)

Path

rules/windows/process_creation/proc_creation_win_susp_registry_modification_of_ms_setting_protocol_handler.yml

Raw Tags

attack.defense-evasionattack.privilege-escalationattack.persistenceattack.t1548.002attack.t1546.001attack.t1112

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