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Detection rules › Sigma

Rundll32 Registered COM Objects

Status
test
Severity
high
Log source
product windows, category process_creation
Author
frack113
Source
github.com/SigmaHQ/sigma

load malicious registered COM objects

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1546.015 Event Triggered Execution: Component Object Model Hijacking
Privilege EscalationT1546.015 Event Triggered Execution: Component Object Model Hijacking

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Rundll32 Registered COM Objects
id: f1edd233-30b5-4823-9e6a-c4171b24d316
status: test
description: load malicious registered COM objects
references:
    - https://nasbench.medium.com/a-deep-dive-into-rundll32-exe-642344b41e90
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.015/T1546.015.md
author: frack113
date: 2022-02-13
modified: 2023-02-09
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.015
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\rundll32.exe'
        - OriginalFileName: 'RUNDLL32.EXE'
    selection_cli:
        CommandLine|contains:
            - '-sta '
            - '-localserver '
        CommandLine|contains|all:
            - '{'
            - '}'
    condition: all of selection_*
falsepositives:
    - Legitimate use
level: high

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith: '\rundll32.exe'
    - OriginalFileName: 'RUNDLL32.EXE'

Stage 2: selection_cli

selection_cli:
    CommandLine|contains:
        - '-sta '
        - '-localserver '
    CommandLine|contains|all:
        - '{'
        - '}'

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
  • -localserver
  • -sta
  • { corpus 2 (sigma 1, splunk 1)
  • } corpus 2 (sigma 1, splunk 1)
Imageends_with
  • \rundll32.exe corpus 95 (sigma 95)
OriginalFileNameeq
  • RUNDLL32.EXE corpus 62 (sigma 35, splunk 21, elastic 6)