Detection rules › Sigma

Suspicious Process Masquerading As SvcHost.EXE

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Swachchhanda Shrawan Poudel
Source
github.com/SigmaHQ/sigma

Detects a suspicious process that is masquerading as the legitimate "svchost.exe" by naming its binary "svchost.exe" and executing from an uncommon location. Adversaries often disguise their malicious binaries by naming them after legitimate system processes like "svchost.exe" to evade detection.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Suspicious Process Masquerading As SvcHost.EXE
id: be58d2e2-06c8-4f58-b666-b99f6dc3b6cd
related:
    - id: 01d2e2a1-5f09-44f7-9fc1-24faa7479b6d
      type: similar
    - id: e4a6b256-3e47-40fc-89d2-7a477edd6915
      type: similar
status: test
description: |
    Detects a suspicious process that is masquerading as the legitimate "svchost.exe" by naming its binary "svchost.exe" and executing from an uncommon location.
    Adversaries often disguise their malicious binaries by naming them after legitimate system processes like "svchost.exe" to evade detection.
references:
    - https://tria.ge/240731-jh4crsycnb/behavioral2
    - https://redcanary.com/blog/threat-detection/process-masquerading/
author: Swachchhanda Shrawan Poudel
date: 2024-08-07
tags:
    - attack.stealth
    - attack.t1036.005
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\svchost.exe'
    filter_main_img_location:
        Image:
            - 'C:\Windows\System32\svchost.exe'
            - 'C:\Windows\SysWOW64\svchost.exe'
    filter_main_ofn:
        OriginalFileName: 'svchost.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_svchost_masqueraded_execution/info.yml

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    Image|endswith: '\svchost.exe'

Stage 2: not filter_main_*

filter_main_img_location:
    Image:
        - 'C:\Windows\System32\svchost.exe'
        - 'C:\Windows\SysWOW64\svchost.exe'
filter_main_ofn:
    OriginalFileName: 'svchost.exe'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
ImageeqC:\Windows\SysWOW64\svchost.exe
ImageeqC:\Windows\System32\svchost.exe
OriginalFileNameeqsvchost.exe

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
Imageends_with
  • \svchost.exe corpus 23 (sigma 23)