host-firewall-defense

host-firewall-defense is a skill for Claude Code, Codex from Threat-Vector-Security/guardian-agent. It costs 0 tokens per session (438 once invoked), scanned A, original, Apache-2.0.

A guide for investigating GuardianAgent alerts about host files, outbound destinations, firewall settings, and gateway firewall findings.

In plain words
What is it for?
Use it to search security alerts, check host or gateway firewall status, refresh stale checks, and manage repetitive findings with a reason and time limit.
Why use it?
It helps distinguish confirmed changes from normal differences and avoids treating every new path or network address as proof of an attack.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to search security alerts, check host or gateway firewall status, refresh stale checks, and manage repetitive findings with a reason and time limit.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/threat-vector-security/guardian-agent/host-firewall-defense
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 Threat-Vector-Security/guardian-agent --skill host-firewall-defense
Clone the repo
git clone --depth 1 https://github.com/Threat-Vector-Security/guardian-agent

Made for: Claude Code, Codex.

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 host-firewall-defense

README.md
[![agentmods](https://agentmods.dev/badge/skills/threat-vector-security/guardian-agent/host-firewall-defense/github.svg)](https://agentmods.dev/skills/threat-vector-security/guardian-agent/host-firewall-defense)
Your own site
<a href="https://agentmods.dev/skills/threat-vector-security/guardian-agent/host-firewall-defense"><img src="https://agentmods.dev/badge/skills/threat-vector-security/guardian-agent/host-firewall-defense/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 host-firewall-defense

Your own site · 80×15
<a href="https://agentmods.dev/skills/threat-vector-security/guardian-agent/host-firewall-defense"><img src="https://agentmods.dev/badge/skills/threat-vector-security/guardian-agent/host-firewall-defense.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 438 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.
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 $0.00000 $0.00438
Opus 5 $0.00000 $0.00219
Sonnet 5 $0.00000 $0.00088
Haiku 4.5 $0.00000 $0.00044

Measured 10d ago against content hash 22d66c696926, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

host-firewall-defense 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 10d 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.

skills/host-firewall-defense/SKILL.md · 39 lines

How it starts

The opening of the file, as written. The whole thing — 39 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Host And Firewall Defense

Use this when the question is specifically about GuardianAgent host-monitor alerts, sensitive path drift, new external destinations, host firewall posture, or gateway firewall findings.

Workflow

  1. Start with the narrowest security view that answers the question.
    • security_alert_search with source: "host" or source: "gateway" when the user is asking about active alerts.
    • host_monitor_status or gateway_firewall_status when they want posture plus counts.
  2. Refresh only when stale state is the problem.
    • host_monitor_check
    • gateway_firewall_check
  3. Separate:
    • confirmed drift or suspicious activity
    • baseline-relative noise
    • alert-hygiene candidates
  4. If the finding is repetitive but expected, use the alert lifecycle tools with a reason and a time bound.

Interpretation Rules

  • sensitive_path_change means the fingerprint changed, not that compromise is confirmed.
  • new_external_destination means GuardianAgent observed a previously unseen outbound address, not that the address is malicious.
  • Treat host and gateway firewall disablement or rule drift as higher-confidence control degradation than a single medium host anomaly.

Boundaries

  • Use native-av-management for Windows Defender, Malwarebytes coexistence, scans, signatures, and Controlled Folder Access.
  • Use network-recon for deeper network diagnostics beyond the alert queue itself.
  • Use security-triage when the work has become a broader incident review rather than focused host or firewall interpretation.
  • Use security-alert-hygiene when the primary task is acknowledge/resolve/suppress workflow rather than technical interpretation.

Gotchas

  • Do not treat GuardianAgent's own state churn as proof of tampering without corroborating evidence.
  • Do not call normal SaaS traffic malicious just because the destination is new to the local baseline.
  • Do not suppress broad classes of alerts without narrowing by source, evidence pattern, and time window.

Read the full file on GitHub · 39 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 10d ago First seen · 39 lines · 0 tokens per session scan A 22d66c696926

Subscribe to this mod's changes

host-firewall-defense is a skill published in the GitHub repository Threat-Vector-Security/guardian-agent (13 stars, last pushed yesterday), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 438 tokens. 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 2026-08-30.

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