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DNS Resolver integration with Snapsec ASM

The DNS Resolver integration enables Snapsec ASM to perform DNS lookups, resolve hostnames, and discover subdomains tied to your external assets.
By resolving DNS records in real time, ASM expands visibility across attack surface assets that may not appear through passive enumeration alone. This integration is essential for:
  • Subdomain discovery
  • Asset enrichment (A, AAAA, CNAME, NS, TXT lookups)
  • Mapping exposed services
  • Detecting shadow or forgotten DNS records

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1. Prerequisites

You do not need API keys or external credentials.
DNS Resolver works immediately once installed. Ensure:
  • The domain you want to resolve is added to Snapsec ASM.
  • Outbound DNS queries are permitted from your environment (if self-hosted).

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2. Enable DNS Resolver in Snapsec ASM

  1. Log in to Snapsec Suite.
  2. Navigate to ASM → Integrations.
  3. Locate DNS Resolver in the integrations list.
  4. Click Install.
Once installed, the adapter becomes active and will automatically start resolving newly discovered assets.

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3. What DNS Resolver Does

After activation, Snapsec ASM will automatically:

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🔹 Resolve DNS Records

Performs live lookups for:
  • A / AAAA
  • CNAME
  • MX
  • NS
  • TXT
  • SOA

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🔹 Discover Subdomains

Resolves domain permutations and passively collected records to detect:
  • Shadow subdomains
  • Developer or staging subdomains
  • Old or forgotten DNS entries

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🔹 Enrich Asset Metadata

Each resolved asset is enhanced with:
  • IP address information
  • Record types
  • TTL values
  • Canonical host relations

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🔹 Detect Exposed Services

Resolved hosts are correlated with:
  • Open ports
  • Active web services
  • Technologies discovered in subsequent scans

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4. How DNS Resolver Works Internally

Once installed:
  1. ASM collects domains from:
    • Organization settings
    • Censys
    • HackerTarget
    • crt.sh (CRT adapter)
    • Manual imports
  2. DNS Resolver runs periodic resolution cycles:
    • Attempts record resolution
    • Identifies new subdomains
    • Flags dead/expired DNS entries
  3. Updated DNS data flows into:
    • Subdomain Catalog
    • IP Catalog
    • Exposure analysis
    • Technology detection workflows
All results remain synchronized automatically.

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5. Troubleshooting

Here are common resolution issues and fixes: ❌ Subdomains not resolving
  • The domain may not exist anymore.
  • TTL expiration may cause intermittent resolution.
  • DNSSEC misconfiguration may block lookups.
❌ No IP address returned
  • The record might be CNAME-only or dormant.
  • The DNS zone may be misconfigured.
❌ Resolver shows timeout
  • Firewall is blocking outbound DNS queries (self-hosted only).
If you continue experiencing issues, contact Snapsec support with the affected domain and resolution logs.

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Next Steps

View Subdomain Catalog

Explore discovered subdomains enriched by DNS Resolver.