Detection rules › Sigma

Network Connection Initiated By Regsvr32.EXE

Status
test
Severity
medium
Log source
product windows, category network_connection
Author
Dmitriy Lifanov, oscd.community
Source
github.com/SigmaHQ/sigma

Detects a network connection initiated by "Regsvr32.exe"

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 3Network connection

Rule body yaml

title: Network Connection Initiated By Regsvr32.EXE
id: c7e91a02-d771-4a6d-a700-42587e0b1095
status: test
description: Detects a network connection initiated by "Regsvr32.exe"
references:
    - https://pentestlab.blog/2017/05/11/applocker-bypass-regsvr32/
    - https://oddvar.moe/2017/12/13/applocker-case-study-how-insecure-is-it-really-part-1/
author: Dmitriy Lifanov, oscd.community
date: 2019-10-25
modified: 2023-09-18
tags:
    - attack.execution
    - attack.stealth
    - attack.t1559.001
    - attack.t1218.010
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        Image|endswith: '\regsvr32.exe'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Initiated: 'true'
    Image|endswith: '\regsvr32.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
  • \regsvr32.exe corpus 65 (sigma 65)
Initiatedeq
  • true corpus 50 (sigma 50)