# T0840_network-connection-enumeration

> Adversaries may perform network connection enumeration to discover information about device communication patterns.

- Skill: `cyberstrikeus/t0840-network-connection-enumeration` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/t0840-network-connection-enumeration`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/t0840-network-connection-enumeration/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/t0840-network-connection-enumeration

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# T0840 Network Connection Enumeration

## High-Level Description

Adversaries may perform network connection enumeration to discover information about device communication patterns. If an adversary can inspect the state of a network connection with tools, such as Netstat, in conjunction with System Firmware, then they can determine the role of certain devices on the network . The adversary can also use Network Sniffing to watch network traffic for details about the source, destination, protocol, and content.

## Kill Chain Phase

- Discovery (TA0102)

**Platforms:** ICS

## What to Check

- [ ] Identify if Network Connection Enumeration technique is applicable to target ICS environment
- [ ] Check ICS/SCADA systems for indicators of Network Connection Enumeration
- [ ] Verify mitigations are bypassed or absent (1 known mitigations)
- [ ] Assess detection coverage (1 detection strategies)

## How to Test

### Identify Attack Surface

Determine if the target ICS/SCADA environment is susceptible to Network Connection Enumeration by examining operational technology systems and network architecture.

### Assess Existing Defenses

Review whether mitigations for T0840 are in place. If defenses are absent or misconfigured, this technique may be exploitable in the ICS environment.

## Remediation Guide

### M0816 Mitigation Limited or Not Effective

Network connection enumeration is likely obtained by using common system tools (e.g., netstat, ipconfig).

## Detection

### Detection of Network Connection Enumeration

## Risk Assessment

| Finding                                             | Severity | Impact    |
| --------------------------------------------------- | -------- | --------- |
| Network Connection Enumeration technique applicable | Low      | Discovery |

## CWE Categories

| CWE ID  | Title                             |
| ------- | --------------------------------- |
| CWE-200 | Exposure of Sensitive Information |

## References

- [MITRE](https://attack.mitre.org/wiki/Technique/T1049)
- [Netstat](https://en.wikipedia.org/wiki/Netstat)
- [MITRE ATT&CK ICS - T0840](https://attack.mitre.org/techniques/T0840)