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Mahipal
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Each rewritten description now states both what the skill does (concrete capability, named tools/artifacts) and an explicit when-to-use trigger, improving agent discovery/activation. Grounded in each skill's own body; changes confined to the `description` field only (bodies and all other frontmatter untouched). Produced by a gated audit->rewrite->recheck loop (548 -> 0 flagged) with a sampled anti-invention check (0 ungrounded). Schema: 817/817 pass. Framework-ID gate: 0 defects.
78 lines
3.1 KiB
Markdown
78 lines
3.1 KiB
Markdown
---
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name: hunting-for-dns-based-persistence
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description: Hunts for DNS-based persistence mechanisms such as DNS hijacking, dangling
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CNAME records enabling subdomain takeover, wildcard DNS abuse, and unauthorized zone
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or NS delegation changes, using passive DNS history (SecurityTrails API), Route53/Azure
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DNS/Cloudflare audit logs, and zone transfer analysis. Use when investigating suspected
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DNS hijacking or subdomain takeover, or when threat hunting for DNS record tampering
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that persists across credential rotations and endpoint reimaging.
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domain: cybersecurity
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subdomain: threat-hunting
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tags:
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- dns
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- persistence
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- threat-hunting
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- passive-dns
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- dns-hijacking
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- subdomain-takeover
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- securitytrails
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version: '1.0'
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author: mahipal
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license: Apache-2.0
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nist_csf:
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- DE.CM-01
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- DE.AE-02
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- DE.AE-07
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- ID.RA-05
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mitre_attack:
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- T1046
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- T1057
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- T1082
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- T1083
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- T1547
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---
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# Hunting for DNS-based Persistence
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## Overview
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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.
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## When to Use
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- When investigating security incidents that require hunting for dns based persistence
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- When building detection rules or threat hunting queries for this domain
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- When SOC analysts need structured procedures for this analysis type
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- When validating security monitoring coverage for related attack techniques
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## Prerequisites
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- SecurityTrails API key (free tier provides 50 queries/month)
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- Access to DNS provider audit logs (Route53, Azure DNS, Cloudflare, or on-premises DNS)
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- Python 3.9+ with requests library
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- DNS zone file access or AXFR capability for internal zones
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- Historical DNS baseline for comparison
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## Steps
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### Step 1: Baseline DNS Records
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Export current DNS zone records and establish baseline for all authorized A, AAAA, CNAME, MX, NS, and TXT records.
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### Step 2: Query Passive DNS History
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Use SecurityTrails API to retrieve historical DNS records and identify unauthorized changes, new subdomains, and CNAME records pointing to decommissioned services (dangling CNAMEs).
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### Step 3: Detect Anomalies
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Compare current records against baseline to identify unauthorized modifications, wildcard records that resolve all subdomains, NS delegation changes, and MX record hijacking.
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### Step 4: Investigate Findings
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Correlate DNS anomalies with threat intelligence feeds, check resolution targets against known malicious infrastructure, and validate record ownership.
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## Expected Output
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JSON report listing DNS anomalies with record type, historical changes, risk severity, and remediation recommendations for each finding.
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