Detection rules › Sigma

PUA - Memory Dump Mount Via MemProcFS

Status
experimental
Severity
high
Log source
product windows, category process_creation
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects execution of MemProcFS a memory forensics tool with the '-device' parameter. MemProcFS mounts physical memory as a virtual file system, allowing direct access to process memory and system structures. Threat actors were seen abusing this utility to mount memory dumps and then extract sensitive information from processes like LSASS or extract registry hives to obtain credentials, LSA secrets, SAM data, and cached domain credentials. MemProcFS usage that is not part of authorized forensic analysis should be treated as suspicious and warrants further investigation.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: PUA - Memory Dump Mount Via MemProcFS
id: 8a1b2c3d-4e5f-6789-abcd-ef1234567890
status: experimental
description: |
    Detects execution of MemProcFS a memory forensics tool with the '-device' parameter.
    MemProcFS mounts physical memory as a virtual file system, allowing direct access to process memory and system structures.
    Threat actors were seen abusing this utility to mount memory dumps and then extract sensitive information from processes like LSASS or extract registry hives to obtain credentials, LSA secrets, SAM data, and cached domain credentials.
    MemProcFS usage that is not part of authorized forensic analysis should be treated as suspicious and warrants further investigation.
references:
    - https://github.com/ufrisk/MemProcFS
    - https://0xdf.gitlab.io/2024/10/05/htb-freelancer.html#
    - https://www.huntress.com/blog/curling-for-data-a-dive-into-a-threat-actors-malicious-ttps
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-04-27
tags:
    - attack.credential-access
    - attack.t1003
    - attack.t1003.001
    - attack.t1003.004
    - attack.t1003.002
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\MemProcFS.exe'
        - OriginalFileName: 'MemProcFS.exe'
        - Description: 'MemProcFS'
    selection_cli:
        CommandLine|contains: '-device'
    condition: all of selection_*
falsepositives:
    - Legitimate use during memory forensics; if not part of authorized analysis, warrants urgent investigation
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_pua_memprocfs/info.yml

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith: '\MemProcFS.exe'
    - OriginalFileName: 'MemProcFS.exe'
    - Description: 'MemProcFS'

Stage 2: selection_cli

selection_cli:
    CommandLine|contains: '-device'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • -device
Descriptioneq
  • MemProcFS
Imageends_with
  • \MemProcFS.exe
OriginalFileNameeq
  • MemProcFS.exe