Suspicious Scan Loop Network

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

Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system

Known false positives

Legitimate script

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter
Discovery	`T1018` Remote System Discovery

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Suspicious Scan Loop Network
id: f8ad2e2c-40b6-4117-84d7-20b89896ab23
status: test
description: Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1018/T1018.md
    - https://ss64.com/nt/for.html
    - https://ss64.com/ps/foreach-object.html
author: frack113
date: 2022-03-12
tags:
    - attack.execution
    - attack.t1059
    - attack.discovery
    - attack.t1018
logsource:
    category: process_creation
    product: windows
detection:
    selection_loop:
        CommandLine|contains:
            - 'for '
            - 'foreach '
    selection_tools:
        CommandLine|contains:
            - 'nslookup'
            - 'ping'
    condition: all of selection_*
falsepositives:
    - Legitimate script
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_loop`

selection_loop:
    CommandLine|contains:
        - 'for '
        - 'foreach '

Stage 2: `selection_tools`

selection_tools:
    CommandLine|contains:
        - 'nslookup'
        - 'ping'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`for` corpus 2 (sigma 2) `foreach` `nslookup` corpus 3 (sigma 3) `ping` corpus 6 (sigma 4, splunk 1, kusto 1)	`field:"CommandLine" kind:match`