# Implementing Attack Surface Management

> Use when implements external attack surface management (EASM) using Shodan, Censys, and ProjectDiscovery tools (subfinder, httpx, nuclei) for asset discovery, subdomain enumeration, service fingerprinting, and exposure scoring. Includes a weighted risk scoring algorithm based on OWASP attack surface analysis methodology and the Relative Attack Surface Quotient (RSQ). Use when building continuous ASM programs or performing external reconnaissance for security assessments.

- Skill: `oyi77/implementing-attack-surface-management` (Agent Skill)
- Install (CLI): `npx skillmds add oyi77/implementing-attack-surface-management`
- Raw SKILL.md: https://api.skillmd.com/api/skills/oyi77/implementing-attack-surface-management/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Product & Planning
- License: Apache-2.0
- Author: oyi77 (https://skillmd.com/u/oyi77)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/oyi77/implementing-attack-surface-management

---


# Implementing Attack Surface Management

## Overview

Cybersecurity skill for implementing attack surface management. Follows industry best practices and security standards.

## When to Use

**Trigger phrases:**
- "implementing attack surface management"
- "When building an external attack surface management (EASM) program from scratch"
- "When performing authorized external reconnaissance for penetration testing engag"
- "When continuously monitoring organizational exposure across internet-facing asse"


- When building an external attack surface management (EASM) program from scratch
- When performing authorized external reconnaissance for penetration testing engagements
- When continuously monitoring organizational exposure across internet-facing assets
- When scoring and prioritizing external attack surface risks for remediation
- When integrating multiple discovery tools into an automated ASM pipeline


## 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 3.8+ with requests, shodan, censys libraries installed
- Shodan API key (free tier provides 100 queries/month)
- Censys API ID and Secret (free tier available)
- ProjectDiscovery tools installed: subfinder, httpx, nuclei
- Go 1.21+ for building ProjectDiscovery tools from source
- Appropriate authorization for all external scanning activities
- Target domains and IP ranges with written scope documentation

## Workflow

```python
# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. **Assess Requirements** — Evaluate current environment and define attack surface management implementation requirements.
2. **Design Architecture** — Plan the attack surface management architecture, including components, integrations, and data flows.
3. **Configure Components** — Set up and configure each attack surface management component according to best practices.
4. **Test Integration** — Validate that all components work together. Run functional and security tests.
5. **Deploy to Production** — Roll out the implementation with monitoring and rollback capabilities.
6. **Validate and Document** — Verify the implementation meets requirements. Document configuration and runbooks.

## Tools

- **Configuration Management** — Infrastructure as code and automation
- **Monitoring Stack** — Observability and alerting
- **Documentation Platform** — Runbooks and architecture docs


## Process

1. **Reconnaissance** — Gather target information, identify attack surface, enumerate services
1. **Analysis/Exploitation** — Execute the technique, analyze results, document findings
1. **Reporting** — Document IOCs, write findings, provide remediation recommendations

## Verification

- [ ] All attack surface management procedures executed completely and documented
- [ ] Findings validated against multiple data sources
- [ ] False positives identified and filtered
- [ ] Results documented with evidence and timestamps
- [ ] Recommendations provided with risk-based prioritization

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |