About

Imported from mukul975/anthropic-cybersecurity-skills (skills/hunting-for-dns-based-persistence/SKILL.md). Install upstream with npx skills add mukul975/anthropic-cybersecurity-skills --skill hunting-for-dns-based-persistence. Copyright stays with the author (Apache-2.0).

Hunting for DNS-based Persistence

Name: hunting-for-dns-based-persistence
Author: mukul975

Overview

Attackers establish DNS-based persistence by hijacking DNS records, creating unauthorized subdomains, abusing wildcard DNS entries, or modifying NS delegations to redirect traffic through attacker-controlled infrastructure. These techniques survive credential rotations, endpoint reimaging, and traditional remediation because DNS changes persist independently of compromised hosts. Detection requires passive DNS historical analysis, zone file auditing, and monitoring for unauthorized record modifications. This skill covers hunting methodologies using SecurityTrails passive DNS API, DNS audit logs from Route53/Azure DNS/Cloudflare, and zone transfer analysis.

When to Use

When investigating security incidents that require hunting for dns based persistence
When building detection rules or threat hunting queries for this domain
When SOC analysts need structured procedures for this analysis type
When validating security monitoring coverage for related attack techniques

Prerequisites

SecurityTrails API key (free tier provides 50 queries/month)
Access to DNS provider audit logs (Route53, Azure DNS, Cloudflare, or on-premises DNS)
Python 3.9+ with requests library
DNS zone file access or AXFR capability for internal zones
Historical DNS baseline for comparison

Steps

Step 1: Baseline DNS Records

Export current DNS zone records and establish baseline for all authorized A, AAAA, CNAME, MX, NS, and TXT records.

Step 2: Query Passive DNS History

Use SecurityTrails API to retrieve historical DNS records and identify unauthorized changes, new subdomains, and CNAME records pointing to decommissioned services (dangling CNAMEs).

Step 3: Detect Anomalies

Compare current records against baseline to identify unauthorized modifications, wildcard records that resolve all subdomains, NS delegation changes, and MX record hijacking.

Step 4: Investigate Findings

Correlate DNS anomalies with threat intelligence feeds, check resolution targets against known malicious infrastructure, and validate record ownership.

Expected Output

JSON report listing DNS anomalies with record type, historical changes, risk severity, and remediation recommendations for each finding.

Use it

Copy one of these into your project. Installing also returns the manifest and these snippets.

yaml

targets:
  - https://api.opensmartroute.ai/api/v1/registry/mukul975-anthropic-cybersecurity-skills-hunting-for-dns-c596d6/manifest   # or paste the manifest below

Manifest

An Open Capability Manifest: the router reads it to know what this does, what it costs and when to pick it.

mukul975-anthropic-cybersecurity-skills-hunting-for-dns-c596d6.ocm.jsonjson

{
  "ocm": "1",
  "id": "mukul975-anthropic-cybersecurity-skills-hunting-for-dns-c596d6",
  "kind": "skill",
  "name": "hunting-for-dns-based-persistence",
  "description": "Hunts for DNS-based persistence mechanisms such as DNS hijacking, dangling CNAME records enabling subdomain takeover, wildcard DNS abuse, and unauthorized zone or NS delegation changes, using passive DNS history (SecurityTrails API), Route53/Azure DNS/Cloudflare audit logs, and zone transfer analysis. Use when investigating suspected DNS hijacking or subdomain takeover, or when threat hunting for DNS record tampering that persists across credential rotations and endpoint reimaging.",
  "publisher": "mukul975",
  "version": "1.0.0",
  "capabilities": {
    "domains": [
      "coding",
      "math"
    ],
    "tags": [
      "skill-md",
      "dns",
      "persistence",
      "threat-hunting",
      "passive-dns",
      "dns-hijacking",
      "subdomain-takeover",
      "securitytrails",
      "skills-sh"
    ],
    "languages": [
      "en"
    ]
  },
  "quality_prior": 0.6,
  "examples": [
    "Hunts for DNS-based persistence mechanisms such as DNS hijacking, dangling CNAME records enabling subdomain takeover, wildcard DNS abuse, and unauthorized zone or NS delegation changes, using passive DNS history (SecurityTrails API), Route53/Azure DNS/Cloudflare audit logs, and zone transfer analysis. Use when investigating suspected DNS hijacking or subdomain takeover, or when threat hunting for DNS record tampering that persists across credential rotations and endpoint reimaging."
  ],
  "primary": false,
  "metadata": {
    "source": {
      "provider": "skills.sh",
      "repository": "https://github.com/mukul975/anthropic-cybersecurity-skills",
      "path": "skills/hunting-for-dns-based-persistence/SKILL.md",
      "ref": "HEAD",
      "url": "https://github.com/mukul975/anthropic-cybersecurity-skills/blob/HEAD/skills/hunting-for-dns-based-persistence/SKILL.md",
      "key": "mukul975/anthropic-cybersecurity-skills/skills/hunting-for-dns-based-persistence/SKILL.md"
    },
    "license": "Apache-2.0"
  },
  "instructions": "# Hunting for DNS-based Persistence\n\n## Overview\n\nAttackers establish DNS-based persistence by hijacking DNS records, creating unauthorized subdomains, abusing wildcard DNS entries, or modifying NS delegations to redirect traffic through attacker-controlled infrastructure. These techniques survive credential rotations, endpoint reimaging, and traditional remediation because DNS changes persist independently of compromised hosts. Detection requires passive DNS historical analysis, zone file auditing, and monitoring for unauthorized record modifications. This skill covers hunting methodologies u",
  "cost": {
    "context_tokens": 570
  }
}

Fetch it by URL: GET /api/v1/registry/mukul975-anthropic-cybersecurity-skills-hunting-for-dns-c596d6/manifest?version=1.0.0

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