Security And Hardening
penpot/penpot
Hardens code against vulnerabilities. An agent skill from penpot/penpot.
Agent skill
Implements external attack surface management (EASM) using Shodan, Censys, and ProjectDiscovery tools (subfinder, httpx, nuclei) for asset discovery, subdomain enumeration, service fingerprinting…
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-management --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/implementing-attack-surface-management .claude/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .claude/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-managementType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-management --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/implementing-attack-surface-management .agents/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .agents/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-management --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/implementing-attack-surface-management .cursor/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .cursor/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git --path skills/implementing-attack-surface-management--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-management --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/implementing-attack-surface-management .gemini/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .gemini/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-managementInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/implementing-attack-surface-management .github/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .github/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install mukul975/Anthropic-Cybersecurity-Skills implementing-attack-surface-management --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/implementing-attack-surface-management .opencode/skills/implementing-attack-surface-management && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "implementing-attack-surface-management" agent skill from https://github.com/mukul975/Anthropic-Cybersecurity-Skills/tree/main/skills/implementing-attack-surface-management into .opencode/skills/implementing-attack-surface-management/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "implementing-attack-surface-management", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
implementing-attack-surface-managementImplements external attack surface management (EASM) using Shodan, Censys, and ProjectDiscovery tools (subfinder, httpx, nuclei) for asset discovery, subdomain enumeration, service fingerprinting…
Implementing Attack Surface Management is an agent skill from mukul975/Anthropic-Cybersecurity-Skills. 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.
Its SKILL.md is about 1.8k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including scripts and reference files (for example `references/api-reference.md`, `references/asm-reference.md` and `scripts/agent.py`).
It sits in Security, covering Threat modeling, OSINT and Web application vulnerabilities. The repository describes itself as: 817 structured cybersecurity skills for AI agents · Mapped to 6 frameworks: MITRE ATT&CK, NIST CSF 2.0, MITRE ATLAS, D3FEND, NIST AI RMF & MITRE F3 (Fight Fraud) · agentskills.io…. The licence is Apache-2.0.
6 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 54a7988. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Ships 1 file in scripts/ (Python), which the agent can run.
Shell commands in SKILL.md call:
pythongoFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Implementing Attack Surface Management loads about 1.8k tokens when it runs, and up to ~5.5k if it reads all its reference files. Until then it costs about 126 tokens; SKILL.md has 286 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
The full file from mukul975/Anthropic-Cybersecurity-Skills at commit 54a7988, republished under its Apache-2.0 licence (© mukul975). 286 words, ~1,788 tokens.
.claude/skills/implementing-attack-surface-management/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.Use subfinder for passive subdomain discovery leveraging dozens of data sources including certificate transparency logs, DNS datasets, and search engines.
# Install ProjectDiscovery tools
go install -v github.com/projectdiscovery/subfinder/v2/cmd/subfinder@latest
go install -v github.com/projectdiscovery/httpx/cmd/httpx@latest
go install -v github.com/projectdiscovery/nuclei/v3/cmd/nuclei@latest
# Basic subdomain enumeration
subfinder -d example.com -o subdomains.txt
# Verbose with all sources and recursive enumeration
subfinder -d example.com -all -recursive -o subdomains_full.txt
# Multi-domain enumeration from file
subfinder -dL domains.txt -o all_subdomains.txt
# Using OWASP Amass for deeper enumeration
amass enum -d example.com -passive -o amass_subdomains.txt
# Merge and deduplicate results
cat subdomains.txt amass_subdomains.txt | sort -u > combined_subdomains.txtProbe discovered subdomains to identify live hosts, technologies, and services.
# HTTP probing with technology detection
cat combined_subdomains.txt | httpx -sc -cl -ct -title -tech-detect \
-follow-redirects -json -o httpx_results.json
# Detailed service fingerprinting
cat combined_subdomains.txt | httpx -sc -cl -ct -title -tech-detect \
-favicon -hash sha256 -jarm -cdn -cname \
-follow-redirects -json -o httpx_detailed.jsonQuery Shodan for exposed services, open ports, and known vulnerabilities associated with discovered assets.
import shodan
api = shodan.Shodan("YOUR_SHODAN_API_KEY")
# Search by organization
results = api.search("org:\"Example Corp\"")
for service in results["matches"]:
print(f"{service['ip_str']}:{service['port']} - {service.get('product', 'unknown')}")
if service.get("vulns"):
for cve in service["vulns"]:
print(f" CVE: {cve}")
# Search by hostname
results = api.search("hostname:example.com")
# Search by SSL certificate
results = api.search("ssl.cert.subject.cn:example.com")
# Get host details with all services
host = api.host("93.184.216.34")
print(f"IP: {host['ip_str']}")
print(f"Ports: {host['ports']}")
print(f"Vulns: {host.get('vulns', [])}")Use Censys to discover internet-facing assets through certificate and host search.
from censys.search import CensysHosts, CensysCerts
# Host search
hosts = CensysHosts()
query = hosts.search("services.tls.certificates.leaf.subject.common_name: example.com")
for page in query:
for host in page:
print(f"IP: {host['ip']}")
for service in host.get("services", []):
print(f" Port: {service['port']} Protocol: {service['transport_protocol']}")
print(f" Service: {service.get('service_name', 'unknown')}")
# Certificate transparency search
certs = CensysCerts()
query = certs.search("parsed.names: example.com")
for page in query:
for cert in page:
print(f"Fingerprint: {cert['fingerprint_sha256']}")
print(f"Names: {cert.get('parsed', {}).get('names', [])}")Run targeted vulnerability scans against discovered assets using Nuclei templates.
# Update nuclei templates
nuclei -ut
# Scan with all templates
cat combined_subdomains.txt | httpx -silent | nuclei -o nuclei_results.txt
# Scan with specific severity
cat combined_subdomains.txt | httpx -silent | \
nuclei -severity critical,high -o critical_findings.txt
# Scan with specific template categories
cat combined_subdomains.txt | httpx -silent | \
nuclei -tags cve,misconfig,exposure -o categorized_findings.txt
# Scan for exposed panels and sensitive files
cat combined_subdomains.txt | httpx -silent | \
nuclei -tags panel,exposure,config -o exposed_panels.txtScore each asset based on OWASP attack surface analysis principles, using a weighted formula derived from the Relative Attack Surface Quotient (RSQ) and damage-potential-to-effort ratio.
The scoring algorithm considers:
# Exposure Score = sum of weighted factors, normalized to 0-100
# See agent.py for the full implementation# Run complete ASM pipeline against a target domain
python agent.py \
--domain example.com \
--action full_scan \
--shodan-key YOUR_KEY \
--censys-id YOUR_ID \
--censys-secret YOUR_SECRET \
--output asm_report.json
# Subdomain enumeration only
python agent.py \
--domain example.com \
--action enumerate \
--output subdomains.json
# Exposure scoring on previously discovered assets
python agent.py \
--domain example.com \
--action score \
--input previous_scan.json \
--output scored_assets.json
# Multi-domain scan from file
python agent.py \
--domain-list targets.txt \
--action full_scan \
--output multi_domain_report.json© mukul975, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
SKILL.md and 4 other files (scripts, references) in skills/implementing-attack-surface-management of mukul975/Anthropic-Cybersecurity-Skills.
Open the folder on GitHubat commit 54a7988
Implementing Attack Surface Management next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Implementing Attack Surface Management this skillmukul975/Anthropic-Cybersecurity-Skills | 34k | — | ~1.8k | Automated safety check: Pass | Apache-2.0 | |
| Security And Hardeningpenpot/penpot | 61k | 6 repos | ~4.7k | Automated safety check: Notes | MPL-2.0 | |
| Security Audit Scannerruvnet/ruflo | 74k | 2 repos | ~823 | Automated safety check: Pass | MIT | |
| Osint Methodologyelementalsouls/Claude-OSINT | 2.8k | — | ~8.7k | Automated safety check: Notes | MIT | |
| Security and Hardeningaddyosmani/agent-skills | 102k | 1 repos | ~4.4k | Automated safety check: Notes | MIT | |
| CybersecurityAgriciDaniel/claude-cybersecurity | 227 | — | ~11k | Automated safety check: Warn | MIT |
penpot/penpot
Hardens code against vulnerabilities. An agent skill from penpot/penpot.
ruvnet/ruflo
Runs claude-flow CLI security scans for input validation, path traversal, SQL injection, XSS, hardcoded secrets and known CVEs, and writes an audit report.
elementalsouls/Claude-OSINT
Comprehensive OSINT methodology for external red-team operations and authorized attack-surface assessments.
addyosmani/agent-skills
Applies a threat-model-first approach to web code that handles untrusted input, authentication, data storage, dependencies or personal data.
AgriciDaniel/claude-cybersecurity
Ultimate AI-powered cybersecurity code review skill. An agent skill from AgriciDaniel/claude-cybersecurity.
garagon/nanostack
Use before shipping to production. An agent skill from garagon/nanostack.
mukul975/Anthropic-Cybersecurity-Skills
Weighs infrastructure, TTP, malware code and timing evidence with the Diamond Model and competing hypotheses to reach a confidence-rated attribution.
mukul975/Anthropic-Cybersecurity-Skills
Walks through reverse engineering Go-compiled malware in Ghidra: parsing buildinfo and pclntab, recovering stripped function names and extracting dependencies.
mukul975/Anthropic-Cybersecurity-Skills
Guides forensic analysis of Windows LNK shortcut files and Jump Lists with LECmd, JLECmd and manual parsing to show file access and program execution.
mukul975/Anthropic-Cybersecurity-Skills
Hunts Windows malware persistence with Sysinternals Autoruns, covering run keys, services, scheduled tasks and drivers, with baseline comparison.
mukul975/Anthropic-Cybersecurity-Skills
Guides a Windows forensic examination of the NTFS Master File Table to recover deleted-file evidence, build timelines and spot timestomping.
mukul975/Anthropic-Cybersecurity-Skills
Detects DNS tunneling, ICMP exfiltration and HTTP-based covert channels in packet captures and DNS logs when hunting for hidden command-and-control traffic.
Categories
Implements external attack surface management (EASM) using Shodan, Censys, and ProjectDiscovery tools (subfinder, httpx, nuclei) for asset discovery, subdomain enumeration, service fingerprinting…. Implementing Attack Surface Management is an agent skill from mukul975/Anthropic-Cybersecurity-Skills. 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.
Implementing Attack Surface Management fits situations like: building continuous ASM programs; performing external reconnaissance for security assessments.
Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a claude-code`. Or copy the skill folder (skills/implementing-attack-surface-management in mukul975/Anthropic-Cybersecurity-Skills) into .claude/skills/implementing-attack-surface-management in your project. Claude Code loads it when a task matches its description.
Run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a codex`. Or copy the skill folder (skills/implementing-attack-surface-management in mukul975/Anthropic-Cybersecurity-Skills) into .agents/skills/implementing-attack-surface-management in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill implementing-attack-surface-management -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/implementing-attack-surface-management, .gemini/skills/implementing-attack-surface-management, .github/skills/implementing-attack-surface-management and .opencode/skills/implementing-attack-surface-management in your project.
Going by SKILL.md and its folder, Implementing Attack Surface Management needs Python for the scripts in its folder and the command-line tools its instructions call (python and go). Our summary lists: Python 3; A credential in YOUR_SHODAN_API_KEY; A credential in YOUR_KEY.
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
Implementing Attack Surface Management is published under the Apache-2.0 licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
About 1.8k tokens (SKILL.md is roughly 7.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 3.7k tokens, read only when the agent opens those files.
Skills that share tags, products or a category with Implementing Attack Surface Management: Security And Hardening (penpot/penpot, 61k stars), Security Audit Scanner (ruvnet/ruflo, 74k stars), Osint Methodology (elementalsouls/Claude-OSINT, 2.8k stars) and Security and Hardening (addyosmani/agent-skills, 102k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
mukul975 (a GitHub user) maintains it in mukul975/Anthropic-Cybersecurity-Skills, which has 33,870 GitHub stars. The repository holds 639 skills in this directory. The repository was last updated on August 31, 2026.
Source: mukul975/Anthropic-Cybersecurity-Skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.