hunting-for-ntlm-relay-attacks

hunting-for-ntlm-relay-attacks is a skill for Claude Code from oyi77/1ai-skills. It costs 79 tokens per session (1,098 once invoked), scanned A, original, MIT.

A cybersecurity guide for finding NTLM relay attacks, where an attacker intercepts Windows login authentication and forwards it to another system to gain access.

In plain words
What is it for?
It is for investigating Windows authentication logs, finding unusual cross-host login patterns, and checking whether SMB signing is enabled.
Why use it?
These attacks can turn a user's legitimate authentication into unauthorized access, often without stealing the password itself. The guide helps identify suspicious logons and weak network protections.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the 1ai-skills plugin — 209 skills, 4 commands shipped together

Good fit It is for investigating Windows authentication logs, finding unusual cross-host login patterns, and checking whether SMB signing is enabled.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add oyi77/1ai-skills --skill hunting-for-ntlm-relay-attacks
Clone the repo
git clone --depth 1 https://github.com/oyi77/1ai-skills

Made for: Claude Code.

Or install 1ai-skills, the plugin that ships this one along with the rest of its 209 skills, 4 commands.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for hunting-for-ntlm-relay-attacks

README.md
[![agentmods](https://agentmods.dev/badge/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks/github.svg)](https://agentmods.dev/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks)
Your own site
<a href="https://agentmods.dev/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks"><img src="https://agentmods.dev/badge/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for hunting-for-ntlm-relay-attacks

Your own site · 80×15
<a href="https://agentmods.dev/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks"><img src="https://agentmods.dev/badge/skills/oyi77/1ai-skills/hunting-for-ntlm-relay-attacks.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,098 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00079 $0.01098
Opus 5 $0.00039 $0.00549
Sonnet 5 $0.00016 $0.00220
Haiku 4.5 $0.00008 $0.00110

Measured 8d ago against content hash 854c1e1e3e4f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

hunting-for-ntlm-relay-attacks scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

cybersecurity/_deprecated/hunting-for-ntlm-relay-attacks/SKILL.md · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hunting for NTLM Relay Attacks

Overview

NTLM relay attacks intercept and forward NTLM authentication messages to gain unauthorized access to network resources. Attackers use tools like Responder for LLMNR/NBT-NS poisoning and ntlmrelayx for credential relay. This skill detects relay activity by querying Windows Security Event 4624 (successful logon) for type 3 network logons with NTLMSSP authentication, identifying mismatches between WorkstationName and source IpAddress, detecting rapid multi-host authentication from single accounts, and auditing SMB signing configuration across domain hosts.

When to Use

Trigger phrases:

  • "hunting for ntlm relay attacks"

  • "Detect NTLM relay attacks by analyzing Windows Event 4624 logon type 3 with NTLM"

  • When investigating security incidents that require hunting for ntlm relay attacks

  • When building detection rules or threat hunting queries for this domain

  • When SOC analysts need structured procedures for this analysis type

  • When validating security monitoring coverage for related attack techniques

When NOT to Use

  • When you lack proper authorization for testing
  • For production systems without change management
  • When the task requires legal or compliance expertise beyond technical scope

Prerequisites

  • Python 3.9+ with Windows Event Log access or exported logs
  • Windows Security audit logging enabled (Event ID 4624, 4625, 5145)
  • Network access for SMB signing status checks

Key Detection Areas

  1. IP-hostname mismatch — WorkstationName in Event 4624 does not resolve to the source IpAddress
  2. NTLMSSP authentication — logon events using NTLM instead of Kerberos from domain-joined hosts
  3. Machine account relay — computer accounts (ending in $) authenticating from unexpected IPs
  4. Rapid authentication — single account authenticating to multiple hosts within seconds
  5. Named pipe access — Event 5145 showing access to Spoolss, lsarpc, netlogon, samr pipes
  6. SMB signing disabled — hosts not enforcing SMB signing, enabling relay attacks

Read the full file on GitHub · 126 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 126 lines · 79 tokens per session scan A 854c1e1e3e4f

Subscribe to this mod's changes

hunting-for-ntlm-relay-attacks is a skill published in the GitHub repository oyi77/1ai-skills (12 stars, last pushed today), licensed MIT. It adds 79 tokens to every session and 1,098 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-04.

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