Detect DNS Queries to OAST Callback and Interaction Service Domains

Detects DNS lookups to common OAST/callback domains that may indicate SSRF-style or blind vulnerability validation.

FreeReviewedSigma · High · v2

Category: dns
Author: Florian Roth (Nextron Systems), Matt Kelly (list of domains) (SigmaHQ), DRL 1.1
Published: 2022-06-07
Updated: 2026-07-31

ATT&CK techniques

Recon → Initial Access

Recon
- T1595.002Vulnerability Scanning
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies DNS queries whose queried name ends with known out-of-band application security testing (OAST) and callback service domains. Attackers and scanners use these domains to confirm blind exploitation paths where a payload triggers an external DNS lookup to a controlled unique subdomain. The detection relies on DNS telemetry, matching query suffixes and excluding queries related to a specific polling pattern to reduce noise. Investigate the requesting host and the full DNS query to determine whether activity aligns with probing/exploitation or internal security scanning.

Reporting behind it

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Detect DNS Queries to OAST Callback and Interaction Service Domains

Pivot detection · T1190 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

dns-queries-to-oast-callback-service-domains-external-dns-interactions-aff715fa

title: Detect DNS Queries to OAST Callback and Interaction Service Domains
id: c93f4ec1-2ea1-4659-8781-d02d6328a761
status: test
description: This rule identifies DNS queries whose queried name ends with known out-of-band application security testing (OAST) and callback service domains. Attackers and scanners use these domains to confirm blind exploitation paths where a payload triggers an external DNS lookup to a controlled unique subdomain. The detection relies on DNS telemetry, matching query suffixes and excluding queries related to a specific polling pattern to reduce noise. Investigate the requesting host and the full DNS query to determine whether activity aligns with probing/exploitation or internal security scanning.
references:
  - https://twitter.com/breakersall/status/1533493587828260866
  - https://www.bitdefender.com/en-us/blog/businessinsights/bitdefender-advisory-critical-unauthenticated-rce-windows-server-update-services-cve-2025-59287
  - https://github.com/SigmaHQ/sigma/pull/5724#issuecomment-3466382234
  - https://hunt.io/blog/open-directory-nginx-rift-ghost-cms-multi-cve
  - https://github.com/SigmaHQ/sigma/blob/master/rules/network/dns/net_dns_external_service_interaction_domains.yml
author: Florian Roth (Nextron Systems), Matt Kelly (list of domains), Huntrule Team
date: 2022-06-07
modified: 2026-07-23
tags:
  - attack.initial-access
  - attack.t1190
  - attack.reconnaissance
  - attack.t1595.002
logsource:
  category: dns
detection:
  selection:
    query|endswith:
      - .burpcollaborator.net
      - .canarytokens.com
      - .ceye.io
      - .ddns.1443.eu.org
      - .ddns.bypass.eu.org
      - .ddns.xn--gg8h.eu.org
      - .digimg.store
      - .dns.su18.org
      - .dnshook.site
      - .dnslog.cn
      - .dnslog.ink
      - .gobygo.net
      - .instances.httpworkbench.com
      - .interact.sh
      - .log.dnslog.pp.ua
      - .log.dnslog.qzz.io
      - .log.dnslogs.dpdns.org
      - .log.javaweb.org
      - .log.nat.cloudns.ph
      - .oast.fun
      - .oast.live
      - .oast.me
      - .oast.online
      - .oast.pro
      - .oast.site
      - .oastify.com
      - .p8.lol
      - .requestbin.net
  filter_main_polling:
    query|contains: polling.oastify.com
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Legitimate security scanning.
level: high
license: DRL-1.1
related:
  - id: aff715fa-4dd5-497a-8db3-910bea555566
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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