How do I install the D3fend Isolate skill?

Run npx skillmds@latest add daemon-blockint-tech/d3fend-isolate 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 Isolate safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with D3fend Isolate?

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 Isolate free to use?

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

Who published D3fend Isolate?

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

D3fend Isolate by daemon-blockint-tech

Name: D3fend Isolate
Author: daemon-blockint-tech

D3fend Isolate

Guides cybersecurity isolation controls using MITRE D3FEND—access mediation, content filtering, execution isolation, and network segmentation. Covers access policies, permissions, content validation, process isolation, allowlisting, and traffic filtering. Use when segmenting networks, restricting access, filtering content, or isolating execution—not for detection (d3fend-detect), hardening (d3fend-harden), or deception (d3fend-deceive).

File contents

D3FEND — Isolate

When to Use

Implementing access mediation (network, file, web session, physical)
Configuring content filtering and validation (format, metadata, magic bytes)
Isolating execution (process sandboxing, allowlisting, denylisting)
Segmenting networks (VLANs, micro-segmentation, broadcast isolation)
Managing DNS/IP allowlists and denylists
Setting system call filtering and I/O port restrictions

When NOT to Use

Building detection rules or monitoring → d3fend-detect
System hardening or encryption → d3fend-harden
Honeypots or deception → d3fend-deceive
Network architecture design → infrastructure-engineer
Zero-trust implementation → cybersecurity

Core Workflows

1. Access Mediation

Type	Controls
Network	VLANs, ACLs, routing mediation, remote file access
Web Session	Proxy-based, endpoint-based mediation
File	Local permissions, access policy administration
Physical	Locks, badges, physical access mediation
System	System call filtering, I/O port restrictions

See references/access_mediation.md

2. Content Filtering & Validation

Content filtering (email, web, DLP)
Content modification, excision, rebuild, substitution
Format verification (magic bytes, metadata, internal structure)
Decompression checking and quarantine

See references/content_filtering.md

3. Execution Isolation

Application-based process isolation (containers, app sandbox)
Kernel-based isolation (seccomp, namespaces, cgroups)
Hardware-based isolation (TEE, TPM, enclaves)
Executable allowlisting and denylisting

See references/execution_isolation.md

4. Network Isolation

Broadcast domain isolation (VLANs, private VLANs)
Directional network links (one-way gateways)
DNS/IP allowlisting and denylisting
Encrypted tunnels (VPN, TLS, IPsec)
Traffic filtering (inbound, outbound, email)

See references/network_isolation.md

When to load references

Access mediation → references/access_mediation.md
Content filtering → references/content_filtering.md
Execution isolation → references/execution_isolation.md
Network isolation → references/network_isolation.md

---name: d3fend-isolatedescription: Guides cybersecurity isolation controls using MITRE D3FEND—access mediation, content filtering, execution isolation, and network segmentation. Covers access policies, permissions, content validation, process isolation, allowlisting, and traffic filtering. Use when segmenting networks, restricting access, filtering content, or isolating execution—not for detection (d3fend-detect), hardening (d3fend-harden), or deception (d3fend-deceive).---# D3FEND — Isolate## When to Use- Implementing access mediation (network, file, web session, physical)- Configuring content filtering and validation (format, metadata, magic bytes)- Isolating execution (process sandboxing, allowlisting, denylisting)- Segmenting networks (VLANs, micro-segmentation, broadcast isolation)- Managing DNS/IP allowlists and denylists- Setting system call filtering and I/O port restrictions## When NOT to Use- Building detection rules or monitoring → `d3fend-detect`- System hardening or encryption → `d3fend-harden`- Honeypots or deception → `d3fend-deceive`- Network architecture design → `infrastructure-engineer`- Zero-trust implementation → `cybersecurity`## Core Workflows### 1. Access Mediation| Type | Controls ||---|---|| Network | VLANs, ACLs, routing mediation, remote file access || Web Session | Proxy-based, endpoint-based mediation || File | Local permissions, access policy administration || Physical | Locks, badges, physical access mediation || System | System call filtering, I/O port restrictions |**See `references/access_mediation.md`**### 2. Content Filtering & Validation- Content filtering (email, web, DLP)- Content modification, excision, rebuild, substitution- Format verification (magic bytes, metadata, internal structure)- Decompression checking and quarantine**See `references/content_filtering.md`**### 3. Execution Isolation- Application-based process isolation (containers, app sandbox)- Kernel-based isolation (seccomp, namespaces, cgroups)- Hardware-based isolation (TEE, TPM, enclaves)- Executable allowlisting and denylisting**See `references/execution_isolation.md`**### 4. Network Isolation- Broadcast domain isolation (VLANs, private VLANs)- Directional network links (one-way gateways)- DNS/IP allowlisting and denylisting- Encrypted tunnels (VPN, TLS, IPsec)- Traffic filtering (inbound, outbound, email)**See `references/network_isolation.md`**## When to load references- **Access mediation** → `references/access_mediation.md`- **Content filtering** → `references/content_filtering.md`- **Execution isolation** → `references/execution_isolation.md`- **Network isolation** → `references/network_isolation.md`

Frequently asked questions