performing-reconnaissance

performing-reconnaissance is a skill for Claude Code from trilwu/secskills. It costs 41 tokens per session (3,422 once invoked), scanned B, original, MIT.

A reconnaissance guide for collecting information about systems before a security assessment. It covers OSINT, which means intelligence from public sources, along with subdomain discovery, port scanning, network mapping, and technology identification.

In plain words
What is it for?
Use it to discover subdomains, public assets, open ports, exposed services, cloud resources, email addresses, and technologies in use.
Why use it?
It helps build a map of an organization's public attack surface so testing can focus on the systems and services that are actually exposed.

Skill for Claude Code

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

Part of the secskills-offense plugin — 40 skills shipped together

Good fit Use it to discover subdomains, public assets, open ports, exposed services, cloud resources, email addresses, and technologies in use.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/trilwu/secskills/performing-reconnaissance
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 trilwu/secskills --skill performing-reconnaissance
Clone the repo
git clone --depth 1 https://github.com/trilwu/secskills

Made for: Claude Code.

Or install secskills-offense, the plugin that ships this one along with the rest of its 40 skills.

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 performing-reconnaissance

README.md
[![agentmods](https://agentmods.dev/badge/skills/trilwu/secskills/performing-reconnaissance/github.svg)](https://agentmods.dev/skills/trilwu/secskills/performing-reconnaissance)
Your own site
<a href="https://agentmods.dev/skills/trilwu/secskills/performing-reconnaissance"><img src="https://agentmods.dev/badge/skills/trilwu/secskills/performing-reconnaissance/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 performing-reconnaissance

Your own site · 80×15
<a href="https://agentmods.dev/skills/trilwu/secskills/performing-reconnaissance"><img src="https://agentmods.dev/badge/skills/trilwu/secskills/performing-reconnaissance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,422 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 10 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 54
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
  • high YARA Match · line 183
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
  • high Privilege Escalation · line 255
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Prompt Injection · line 465
    Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.
    Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
  • medium YARA Match · line 161
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
  • medium Privilege Escalation · line 190
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • medium Privilege Escalation · line 197
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • medium Privilege Escalation · line 341
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • medium Privilege Escalation · line 342
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
  • medium Privilege Escalation · line 214
    Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.
    Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
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 $0.00041 $0.03422
Opus 5 $0.00020 $0.01711
Sonnet 5 $0.00008 $0.00684
Haiku 4.5 $0.00004 $0.00342

Measured 6d ago against content hash 3b46058e819c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

performing-reconnaissance scanned grade B with 2 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 6d 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo nmap -sU --top-ports 1000 target.com

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://crt.sh/?q=%25.domain.com&output=json" | jq -r '.[].name_value' | sort -u
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

secskills-offense/skills/performing-reconnaissance/SKILL.md · 487 lines

How it starts

The opening of the file, as written. The whole thing — 487 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Initial Access and Reconnaissance Skill

You are an offensive security expert specializing in reconnaissance, OSINT, and initial access techniques. Use this skill when the user requests help with:

  • External reconnaissance and information gathering
  • Subdomain enumeration
  • Port scanning strategies
  • OSINT techniques
  • Public exposure detection
  • Network mapping
  • Service fingerprinting
  • Vulnerability scanning

When to Use

Activate this skill when the user asks to:

  • Perform reconnaissance on a target
  • Enumerate subdomains
  • Discover attack surface
  • Find public exposures
  • Gather OSINT information
  • Map network infrastructure
  • Identify technologies in use
  • Help with initial access techniques

Scope and authorization. Passive collection against public sources is generally lawful; the moment you send packets to a host you are acting under whatever authorization you hold, and unauthorized scanning is a criminal offense in most jurisdictions (CFAA in the US, Computer Misuse Act in the UK). Two failure modes specific to recon:

  • Inherited infrastructure. Subdomain and ASN enumeration walks into third-party estate constantly — the CDN, the SaaS tenant, the shared host, the acquired subsidiary nobody listed. Resolve ownership before you probe; "it was in the DNS tree" is not authorization.
  • OSINT on people. Employee enumeration, credential-dump correlation, and social-profile harvesting are personal-data processing under GDPR and similar regimes. Confirm the engagement covers it, and keep what you collect inside the engagement.

Get the target list, the explicitly excluded ranges, and the active-testing window in writing before the first active probe.

When NOT to Use

  • You already have network access — use enumerating-network-services
  • Code-level review of a known target — use auditing-code-for-vulnerabilities
  • Pretext development for a phishing campaign — use performing-social-engineering
  • Investigating an adversary rather than a target — use hunting-threats

Read the full file on GitHub · 487 lines

Files

What ships with it

1 file 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. 6d ago First seen · 487 lines · 41 tokens per session scan B 3b46058e819c

Subscribe to this mod's changes

performing-reconnaissance is a skill published in the GitHub repository trilwu/secskills (138 stars, last pushed 5d ago), licensed MIT. It adds 41 tokens to every session and 3,422 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 2 findings (asks for root, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

Other skills, from other repositories

claude-md-improver

Audit and improve CLAUDE.md files in repositories. Use when user asks to check, audit, update, improve, or fix CLAUDE.md files. Scans for all CLAUDE.md files, evaluates quality against templates, outputs quality report, then makes targeted updates. Also use when the user mentions "CLAUDE.md maintenance" or "project…

anthropics/claude-plugins-official · 82 tokens

agent-platform-rag-engine-management

Manage and query Agent Platform RAG Engine Corpora and retrieve grounded contexts using the Google GenAI SDK. Use when listing RAG corpora or files, inspecting a corpus, retrieving contexts, or generating content grounded in a RAG corpus. Do not use for standard database queries (use SQL/Spanner skills), Google…

google/skills · 85 tokens

gke-workload-security

Audits, configures, and hardens workload-level security controls for Google Kubernetes Engine (GKE) applications and namespaces. Covers running cluster security audits (auditcluster.sh), configuring Workload Identity Federation (impersonation, KSA/GSA binding, and pod setup), enforcing Network Policies (default-deny…

google/skills · 181 tokens

gke-reliability

Improves GKE workload reliability, using PDBs, health probes, and topology spread constraints. Use when configuring GKE workload reliability, setting up PDBs, or configuring GKE health probes (liveness, readiness, startup). Don't use for disaster recovery setup or full cluster backups (use gke-backup-dr instead).

google/skills · 73 tokens

agent-platform-model-registry

Agent Platform Model Registry Management. Use when you need to upload, list, describe, update, or delete machine learning models (and their versions) in the Agent Platform Model Registry. Don't use for model training, model deployment to endpoints, or managing non-Agent Platform models.

google/skills · 60 tokens

google-cloud-solution-agentic-analytics-spark-knowledge-catalog

Discovers requirements and generates guidance to design and deploy a governed, secure agentic-analytics solution for data that's distributed across Google Cloud, other cloud providers, or on-premises. Data that's outside Google Cloud (such as data from Databricks, Snowflake, Salesforce, SAP, or Oracle systems) is…

google/skills · 138 tokens