Detection rules › Sigma

Suspicious Wordpad Outbound Connections

Status
test
Severity
medium
Log source
product windows, category network_connection
Author
X__Junior (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a network connection initiated by "wordpad.exe" over uncommon destination ports. This might indicate potential process injection activity from a beacon or similar mechanisms.

MITRE ATT&CK coverage

TacticTechniques
StealthNo specific technique
Command & ControlNo specific technique

Event coverage

ProviderEventTitle
SysmonEvent ID 3Network connection

Rule body yaml

title: Suspicious Wordpad Outbound Connections
id: 786cdae8-fefb-4eb2-9227-04e34060db01
status: test
description: |
    Detects a network connection initiated by "wordpad.exe" over uncommon destination ports.
    This might indicate potential process injection activity from a beacon or similar mechanisms.
references:
    - https://blogs.blackberry.com/en/2023/07/romcom-targets-ukraine-nato-membership-talks-at-nato-summit
author: X__Junior (Nextron Systems)
date: 2023-07-12
modified: 2023-12-15
tags:
    - attack.command-and-control
    - attack.stealth
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        Image|endswith: '\wordpad.exe'
    filter_main_ports:
        DestinationPort:
            - 80
            - 139
            - 443
            - 445
            - 465
            - 587
            - 993
            - 995
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Other ports can be used, apply additional filters accordingly
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    Initiated: 'true'
    Image|endswith: '\wordpad.exe'

Stage 2: not filter_main_ports

filter_main_ports:
    DestinationPort:
        - 80
        - 139
        - 443
        - 445
        - 465
        - 587
        - 993
        - 995

Exclusions

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

FieldKindExcluded values
DestinationPorteq139
DestinationPorteq443
DestinationPorteq445
DestinationPorteq465
DestinationPorteq587
DestinationPorteq80
DestinationPorteq993
DestinationPorteq995

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
  • \wordpad.exe corpus 5 (sigma 5)
Initiatedeq
  • true corpus 50 (sigma 50)