How do I install the D3fend Harden skill?

Run npx skillmds@latest add daemon-blockint-tech/d3fend-harden in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is D3fend Harden safe to use?

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Which AI agents work with D3fend Harden?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is D3fend Harden free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published D3fend Harden?

daemon-blockint-tech (@daemon-blockint-tech) published this skill. Their other Agent Skills are listed on their SkillMD profile.

D3fend Harden by daemon-blockint-tech

Name: D3fend Harden
Author: daemon-blockint-tech

D3fend Harden

Guides cybersecurity hardening controls using MITRE D3FEND—authentication, application hardening, credential management, message integrity, platform security, and source code defenses. Covers MFA, certificate pinning, control flow integrity, encryption, input validation, and secure configuration. Use when hardening systems, configuring auth, implementing encryption, or reviewing code security—not for detection rules (d3fend-detect), network segmentation (d3fend-isolate), or incident response (d3fend-evict).

daemon-blockint-tech a027fc9 5 files · 10.3 KB Updated Sep 17, 2026

File contents

D3FEND — Harden

When to Use

Implementing authentication controls (MFA, certificates, biometrics, tokens)
Hardening applications and platforms (configuration, patches, encryption)
Managing credential lifecycle (rotation, pinning, scrubbing, policies)
Validating input and enforcing domain/operational logic
Securing source code (memory safety, pointer validation, dead code elimination)
Reviewing boot integrity, driver signing, and firmware protections

When NOT to Use

Detection engineering or monitoring → d3fend-detect
Network segmentation or access mediation → d3fend-isolate
Decoy and deception operations → d3fend-deceive
Incident response or eviction → d3fend-evict
Secure coding deep dives → devsecops / senior-software-engineer

Core Workflows

1. Authentication Hardening

Control	Implementation
Multi-factor Authentication	TOTP, WebAuthn, hardware keys
Certificate-based Auth	mTLS, client certs, PKI
Biometric Auth	Fingerprint, face, behavioral
Token-based Auth	JWT with short expiry, rotation
Password Policy	Length, complexity, breach check

See references/authentication.md

2. Application & Platform Hardening

Application config hardening (disable unused features, remote access)
Control flow integrity (CFI, stack canaries, ASLR, pointer auth)
Bootloader authentication, TPM boot integrity
Disk/file encryption, hardware write protection
Software update management, driver load integrity

See references/application_platform.md

3. Credential & Message Hardening

Credential rotation (certs, passwords, tokens)
Certificate pinning (mobile, embedded)
Message authentication (HMAC, MAC) and encryption
Token binding to prevent session hijacking

See references/credential_message.md

4. Source Code Hardening

Input validation (range, type, pointer, null checks)
Memory safety (initialization, nullification, bounds)
Use trusted libraries, eliminate dead code
Exception handler validation, domain logic checks

See references/source_code.md

When to load references

Authentication → references/authentication.md
Application & platform → references/application_platform.md
Credential & message → references/credential_message.md
Source code → references/source_code.md

---name: d3fend-hardendescription: Guides cybersecurity hardening controls using MITRE D3FEND—authentication, application hardening, credential management, message integrity, platform security, and source code defenses. Covers MFA, certificate pinning, control flow integrity, encryption, input validation, and secure configuration. Use when hardening systems, configuring auth, implementing encryption, or reviewing code security—not for detection rules (d3fend-detect), network segmentation (d3fend-isolate), or incident response (d3fend-evict).---# D3FEND — Harden## When to Use- Implementing authentication controls (MFA, certificates, biometrics, tokens)- Hardening applications and platforms (configuration, patches, encryption)- Managing credential lifecycle (rotation, pinning, scrubbing, policies)- Validating input and enforcing domain/operational logic- Securing source code (memory safety, pointer validation, dead code elimination)- Reviewing boot integrity, driver signing, and firmware protections## When NOT to Use- Detection engineering or monitoring → `d3fend-detect`- Network segmentation or access mediation → `d3fend-isolate`- Decoy and deception operations → `d3fend-deceive`- Incident response or eviction → `d3fend-evict`- Secure coding deep dives → `devsecops` / `senior-software-engineer`## Core Workflows### 1. Authentication Hardening| Control | Implementation ||---|---|| Multi-factor Authentication | TOTP, WebAuthn, hardware keys || Certificate-based Auth | mTLS, client certs, PKI || Biometric Auth | Fingerprint, face, behavioral || Token-based Auth | JWT with short expiry, rotation || Password Policy | Length, complexity, breach check |**See `references/authentication.md`**### 2. Application & Platform Hardening- Application config hardening (disable unused features, remote access)- Control flow integrity (CFI, stack canaries, ASLR, pointer auth)- Bootloader authentication, TPM boot integrity- Disk/file encryption, hardware write protection- Software update management, driver load integrity**See `references/application_platform.md`**### 3. Credential & Message Hardening- Credential rotation (certs, passwords, tokens)- Certificate pinning (mobile, embedded)- Message authentication (HMAC, MAC) and encryption- Token binding to prevent session hijacking**See `references/credential_message.md`**### 4. Source Code Hardening- Input validation (range, type, pointer, null checks)- Memory safety (initialization, nullification, bounds)- Use trusted libraries, eliminate dead code- Exception handler validation, domain logic checks**See `references/source_code.md`**## When to load references- **Authentication** → `references/authentication.md`- **Application & platform** → `references/application_platform.md`- **Credential & message** → `references/credential_message.md`- **Source code** → `references/source_code.md`

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