title: SMB Lateral Movement
id: 162819cf-fcf8-5cb9-a342-4f1834a388e9
custom_id: wf-net-012
status: stable
level: high
description: |
    Detects SMB (Server Message Block) connections between workstations that may
    indicate lateral movement. Legitimate SMB traffic typically flows from
    workstations to file servers, not between workstations.
author: WitFoo
date: 2026-02-21
tags:
    - attack.lateral_movement
    - attack.t1021.002
references:
    - https://attack.mitre.org/techniques/T1021/002/
logsource:
    product: witfoo
    service: artifact-exporter
detection:
    selection:
        serverPort:
            - "445"
            - "139"
    selection_stream:
        streamName|contains:
            - "smb"
            - "zeek_smb"
    condition: selection or selection_stream
fields:
    - clientIP
    - serverIP
    - serverPort
    - userName
    - fileName
    - streamName
falsepositives:
    - File server access from workstations (expected traffic)
    - Network printing over SMB
    - AD Group Policy processing
