HackTool - NetExec Execution

Status: experimental
Severity: high
Log source: category process_creation, product windows
Author: Chirag Damani
Source: github.com/SigmaHQ/sigma

Detects execution of the hacktool NetExec. NetExec (formerly CrackMapExec) is a widely used post-exploitation tool designed for Active Directory penetration testing and network enumeration In enterprise environments, the use of NetExec is considered suspicious or potentially malicious because it enables attackers to enumerate hosts, exploit network services, and move laterally across systems. Threat actors and red teams commonly use NetExec to identify vulnerable systems, harvest credentials, and execute commands remotely.

Known false positives

Legitimate use of NetExec by security professionals or system administrators for network assessment and management.

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1018` Remote System Discovery
Lateral Movement	`T1021` Remote Services

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: HackTool - NetExec Execution
id: 7638e5fe-600c-4289-a968-f49dd537ec7d
status: experimental
description: |
    Detects execution of the hacktool NetExec.
    NetExec (formerly CrackMapExec) is a widely used post-exploitation tool designed for Active Directory penetration testing and network enumeration
    In enterprise environments, the use of NetExec is considered suspicious or potentially malicious because it enables attackers to enumerate hosts, exploit network services, and move laterally across systems.
    Threat actors and red teams commonly use NetExec to identify vulnerable systems, harvest credentials, and execute commands remotely.
references:
    - https://thedfirreport.com/2025/12/17/cats-got-your-files-lynx-ransomware/
    - https://github.com/Pennyw0rth/NetExec
    - https://www.netexec.wiki/
author: Chirag Damani
date: 2026-03-29
tags:
    - attack.discovery
    - attack.t1018
    - attack.lateral-movement
    - attack.t1021
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\nxc.exe'
        CommandLine|contains:
            - ' ftp '
            - ' ldap '
            - ' mssql '
            - ' nfs '
            - ' rdp '
            - ' smb '
            - ' ssh '
            - ' vnc '
            - ' winrm '
            - ' wmi '
    condition: selection
falsepositives:
    - Legitimate use of NetExec by security professionals or system administrators for network assessment and management.
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_hktl_netexec/info.yml

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    Image|endswith: '\nxc.exe'
    CommandLine|contains:
        - ' ftp '
        - ' ldap '
        - ' mssql '
        - ' nfs '
        - ' rdp '
        - ' smb '
        - ' ssh '
        - ' vnc '
        - ' winrm '
        - ' wmi '

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`ftp` `ldap` `mssql` corpus 2 (sigma 2) `nfs` `rdp` `smb` corpus 2 (sigma 2) `ssh` `vnc` `winrm` `wmi`	`field:"CommandLine" kind:match`
`Image`	ends_with	`\nxc.exe`	`field:"Image" kind:ends_with value:"\nxc.exe"`