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DNS Tool
Engineer's DNS Intelligence Report
Generated 9 Feb 2026, 05:00 UTC
Duration 25.5s
Version v26.10.79
Integrity 87ba213d08fc917bd4a2108c6a79d459a972ba43de524f773fd1acc4b5d06821865de7ebc71ff751947e06eb47db209a37f82ac27c6b46f29b495091cada7dc5
Subject Domain
github.com

Engineer's DNS Intelligence Report

github.com
9 Feb 2026, 05:00 UTC · 25.5s ·v26.10.79 · SHA-3-512: 87ba✱✱✱✱ Verify
Executive Methodology
Recon Mode Snapshot Re-analyze New Domain
Footprint Amazon Route 53 Google Workspace
DNS Security & Trust Posture
Risk Level: STRONG (Monitoring)
2 protocols configured, 5 not configured Why we go beyond letter grades
1 monitoring
Suggested Scanner Configuration High Confidence
Based on 20 historical scans of this domain
Parameter Current Suggested Severity Rationale
timeout_seconds 5s 8s low Average scan duration is 31.9s, suggesting DNS responses are slow for this domain. Increasing timeout from 5s to 8s prevents premature resolution failures.
RFC 8767
Suggestions require explicit approval before applying. No automatic changes will be made.
Email Spoofing
Protected
Brand Impersonation
Not Setup
DNS Tampering
Enterprise
Certificate Control
Configured
Monitoring
DKIM (weak 1024-bit keys, upgrade to 2048)
Configured
DMARC (email spoofing protection), CAA (certificate issuance restricted)
Not Configured
DNSSEC (DNS response signing), DANE not available on Google Workspace — deploy MTA-STS as the recommended transport security alternative, MTA-STS (email TLS policy), TLS-RPT (TLS delivery reporting), BIMI (brand logo in inboxes)
Registrar (RDAP) LIVE
Markmonitor Inc. (Registrant: REDACTED REGISTRANT)
Where domain was purchased
Email Service Provider
Google Workspace
Email: Enabled
Web Hosting
Amazon Route 53
Where website is hosted
DNS Hosting
Amazon Route 53 Enterprise
Where DNS records are edited
Email Security Methodology Can this domain be impersonated by email? No
Verdict: DMARC policy is reject - spoofed messages will be blocked by receiving servers.

SPF Record RFC 7208 §4 Verified

Does this domain declare who may send email on its behalf? Yes
Success ~all 8/10 lookups

SPF valid with industry-standard soft fail (~all), 8/10 lookups

v=spf1 ip4:192.30.252.0/22 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com include:spf.protection.outlook.com include:mail.zendesk.com include:_spf.salesforce.com include:servers.mcsv.net include:mktomail.com ip4:62.253.227.114 ip4:166.78.69.169 ip4:166.78.69.170 ip4:166.78.71.131 ip4:167.89.101.2 ip4:167.89.101.192/28 ip4:192.254.112.60 ip4:192.254.112.98/31 ip4:192.254.113.10 ip4:192.254.113.101 ip4:192.254.114.176 ~all
RFC 7208 Conformant — This SPF record conforms to the syntax and semantics defined in RFC 7208 §4.
RFC Failure Mode: Unlike DMARC (where unknown tags are silently ignored per RFC 7489 §6.3), SPF with unrecognized mechanisms produces a PermError per RFC 7208 §4.6 — the record fails loudly rather than silently.
Related CVEs: CVE-2024-7208 (multi-tenant domain spoofing), CVE-2024-7209 (shared SPF exploitation), CVE-2023-51764 (SMTP smuggling bypasses SPF)
~all is the industry standard. Google, Apple, and most providers default to soft fail. CISA (BOD 18-01) and RFC 7489 confirm that DMARC policy — not SPF alone — is the primary enforcement control. Using ~all allows DKIM to be evaluated before a DMARC decision is made. This domain uses ~all + DMARC reject: the strongest compatible security stance, aligned with CISA and RFC guidance.

DMARC Policy RFC 7489 §6.3 Verified

Are spoofed emails rejected or quarantined? Yes — reject policy
Success p=reject

DMARC policy reject (100%) - excellent protection

v=DMARC1; p=reject; pct=100; rua=mailto:dmarc@github.com
Alignment: SPF relaxed DKIM relaxed
No np= tag (DMARCbis) — non-existent subdomains inherit p= policy but adding np=reject provides explicit protection against subdomain spoofing
RFC 7489 Conformant — DMARC record conforms to RFC 7489 §6.3 with full enforcement.
DMARCbis (Pending): draft-ietf-dmarc-dmarcbis will elevate DMARC to Standards Track, obsolete RFC 7489, replace pct= with t= (testing flag), add np= (non-existent subdomain policy), and mandate DNS tree walk for policy discovery instead of the Public Suffix List.
Related CVEs: CVE-2024-49040 (Exchange sender spoofing), CVE-2024-7208 (multi-tenant DMARC bypass)

DKIM Records RFC 6376 §3.6 Verified

Are outbound emails cryptographically signed? Not discoverable
Weak Keys 2048-bit

Found 8 DKIM selector(s) with weak key(s) (1024-bit)

1024-bit key (weak, upgrade to 2048)
cm._domainkey Campaign Monitor 2048-bit
k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXLybkpDQnCyQYlQc46kL2sPMsYDqwkjPyFRSDiaq6qUeujAlU775+f8rzxIrjHc8sPstAZOuJzqcgDPiidRxdE2Th/lcnfbN4btWvJwHKK6KD/IazNWNqQtunYyPzfmSRTtOE4Nii4Oxwx1glTJAVhCTObD2uh2U44lCG+pgYswIDAQAB
google._domainkey Google Workspace 2048-bit
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAj6T5sl/RwdSqGoYWaWaFbS2UAeyPrEmd0gogocmRfS441qwR8/0KB81Hw89P0l4YiFRrXYk7NVIGfyCRHAYYZUzCkGeOysI2EjgzLFhd/NEsbRzOEc/kWkK/RO6JFq/5lOn6M9AZw/ap9tds4JG9ApgNNdSpPxp9DmvpsOSgNMVflRxQFrk3kdS4RNAPKu/" "OPoA7dlR/A/pECryjRoYgENtDXzdnK70HgCekems6UDzxDj61cjyoKoXtEMF/QsaHEQ1Gjfv014rDJBsubk/kT5VqHkWHa/ia68Z5r228Ety/wFfQNjXTx/J7KGZ9GkZlKED659eiJcLnWcKDSiQlhwIDAQAB
k1._domainkey MailChimp 2048-bit
k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDbNrX2cY/GUKIFx2G/1I00ftdAj713WP9AQ1xir85i89sA2guU0ta4UX1Xzm06XIU6iBP41VwmPwBGRNofhBVR+e6WHUoNyIR4Bn84LVcfZE20rmDeXQblIupNWBqLXM1Q+VieI/eZu/7k9/vOkLSaQQdml4Cv8lb3PcnluMVIhQIDAQAB;
k2._domainkey MailChimp
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv2aC2KjGKLOwTweBY5A9RpjsxaBXR9r7OAU6U8/zn92ivImI75naUujWbItRI/QmL1jy5PWGqLwoUA0b90ObWaLDc+i9MtTNmGeWO009hr20fIxhGg6XBT2kjZ1DTThopSe1nAndsupmcBwlQ5Q6LJ+ZAxLcujnPIxM0ZBLmgpkv8u6RfY4eFP8OLvdAW3oSu" "B0DyLDigQX4Sj8wBO4YIdQH6AAmBeOsidsKAFNFUCpc3vCxtBDR12U+cBg724l3sBkMQ8evnz6idnqxq9QAVYh8k4kJ+RP+6cqTdy7LjIm8xY/bQNpQIpGUAuDo2DjLcCDun9DAI4Q/3z+Q0o9QuQIDAQAB;
s1._domainkey SendGrid
k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyn3fMCVpb7ryIRKOGXhXVGYmsWUitNlSckqGHOwNFZgFadplOrD+Qzf1XQkP7MH/VB/97DsAAJGtEXW1Uq71Hjnfr/DuBN/YfjF/gU70qEFb7q1sdIiNtjFL2TkOpoW+X/bhhPNheW/fYwyFb6ZHFM6LTgXyuimWRHTOUP3VjZzhNVda79nt+2WZYbS4l8HdMgWpT" "NHjpVw5PtXESA9KBg/evSRk5fIaXIX5eRXW3baoV9yVzD8O29/IL/DiSk+yNvaO0EHL5c4yGuZJhGzvpiznb2IDVdemJK4Dqzdy5FTN/SGYZhAEr7MguG3Z314hMS2scgMsOMgB64uj/6+6UwIDAQAB
s2._domainkey SendGrid
k=rsa; t=s; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnNt2/H6bKs99C6DAaokPp62KN9mKaD20D1PBakkObejkJvzM6Un/fKHPeI2/qXdvFFBPQE3mxMNoe+hwBVDgMgCuZEn8J6gZYI4amITure9/ny6+GaNVRoH2m6xAtWwKINkKxMayGiehkWlRVb7D23F0U8y+VDHKQFz1bnXA5jDpcDiMXy8i2lV5vEys+qt+1WGhD" "KCAwamT8c3xkZz8aXMJaXYCiN2HMgHDU81+mVCk4+u6mY+a98APVfFhsQ0KCq/mVZXaXTV06QrG9M5PtBHUFW7VtwXKp+AFrAut0KW1NnwaA5IGA5sc+n9dma7bSqdfGS+ixdSmJ69NwmYSHwIDAQAB
zendesk1._domainkey Zendesk 1024-bit
v=DKIM1;t=s;n=core;k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA9IqdLrO3Zr2/56MHt8oQVCQorP0Bl2Fz9sM2tFBnJCdB/HogQmuudEg2xAovCN2PYpw44UijIvPuBoT9vxiv6ZCBJTLJXa82r6ke5rE4tbe9" "NKFIrVIb9S306cJDrnKFMDb8p0dU/Su0+eUR5gVAOtCuz2L8HAzs5edvsEvD/Fb4ny1RLNSEPZkIQLfGhVxQeWANm3+1Jwb/OBVXV9k0nKpWrpgqcmO7NzroJirp014RQY7rGi60JLUubc6XhvoFQBQrtOAdVlZC5wvfS1bgpq5kQpdP7cajIqWCeqxPTeo0ZUpey2ZcaygEsZz0Z3Gs5wDzyuqd7/ADpr2jNF7ozwIDAQAB
zendesk2._domainkey Zendesk
v=DKIM1; t=s; n=core; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAmiSFNkgXrO3I8aOaPONDZWHv027rkiGIwb838OyXPgvFDEkCV/qGcdXSjZnaVAadrTm/oKnL8WOltP9zB1FLEuKt0fTi5zRyKPE4oIYCnEzXwrGqzjUcCABQBawQV" "qvXjDOaYh9Lhp8W5PYOLo905vRW7ipyIMDhuzBOJls91/WWXnNK0OwP3RghiisZjA3K2KqtRwf7w6GjNeNuAMNhvcmgAN15d/mhK+dev/hcRbal66RoYyTD8c0F0isahWH0envEX8aj+SBhheNk0/U37dGE+4nFaY5yP9CUlYjFKDSIKZgHzG4Hci3t/RubU58pi6BCrQQdAFvIOeDFeCZ0ywIDAQAB
RFC 6376 (Provider-Managed) — DKIM signing managed by the detected mail provider per RFC 6376.
Known Vulnerabilities: DKIM l= tag body length vulnerability (attacker appends unsigned content to signed mail), weak key exploitation (keys below 1024-bit are cryptographically breakable per RFC 6376 §3.3.3), DKIM replay attacks (re-sending legitimately signed messages at scale)

MTA-STS RFC 8461 §3 Verified

Can attackers downgrade SMTP to intercept mail? Not prevented
Warning

No MTA-STS record found

MTA-STS policy enforcement is evaluated in Mail Transport Security below.

TLS-RPT RFC 8460 §3 Verified

Will failures in TLS delivery be reported? No reporting
Warning

No TLS-RPT record found

DANE / TLSA Verified Recon Methodology Can mail servers establish identity without a public CA? No
RFC 7672 §3 RFC 6698 §2 Not Available

DANE not available — Google Workspace does not support inbound DANE/TLSA on its MX infrastructure

DANE not deployable on Google Workspace

Google uses shared, multi-tenant MX infrastructure (aspmx.l.google.com) with certificate rotation. Google does not publish TLSA records for its MX hosts and does not allow customers to do so. Google also does not validate DANE/TLSA when sending outbound mail.

Recommended alternative: MTA-STS

Email Transport Security

Two mechanisms protect email in transit. DANE is the primary standard; MTA-STS is the alternative for domains that cannot deploy DNSSEC:

  • DNSSEC + DANE (RFC 7672) — Cryptographic chain of trust from DNS root to mail server certificate. Eliminates reliance on certificate authorities. No trust-on-first-use weakness. Requires DNSSEC.
  • MTA-STS (RFC 8461) — HTTPS-based policy requiring TLS for mail delivery. Works without DNSSEC but relies on CA trust and is vulnerable on first use (§10). Created for domains where “deploying DNSSEC is undesirable or impractical” (§2).
This domain has neither DANE nor MTA-STS. Since Google Workspace does not support inbound DANE, deploy MTA-STS (RFC 8461) to enforce TLS and protect against downgrade attacks.

Industry trend: Microsoft Exchange Online enforces inbound DANE with DNSSEC (GA October 2024), and providers like Proton Mail and Fastmail also support DANE. Google Workspace does not support DANE and relies on MTA-STS. Both mechanisms coexist because DANE is backward-compatible — senders skip the check if the domain isn't DNSSEC-signed (RFC 7672 §1.3).

Brand Security Can this brand be convincingly faked?
Verdict: Certificate issuance is controlled but brand logo (BIMI) is not configured.

BIMI BIMI Spec Verified Warning

Is the brand identity verified and displayed in inboxes? No

No BIMI record found

CAA RFC 8659 §4 Verified Success

Does this domain restrict who can issue TLS certificates? Yes

CAA configured - only DigiCert, Let's Encrypt, Sectigo, GlobalSign can issue certificates (including wildcards)

Authorized CAs: DigiCert Let's Encrypt Sectigo GlobalSign
0 issue "sectigo.com"
0 issuewild "letsencrypt.org"
0 issue "letsencrypt.org"
0 issue "globalsign.com"
0 issue "digicert.com"
0 issuewild "digicert.com"
0 issuewild "sectigo.com"
Since September 2025, all public CAs must verify domain control from multiple geographic locations (Multi-Perspective Issuance Corroboration, CA/B Forum Ballot SC-067). CAA records are now checked from multiple network perspectives before certificate issuance.
Domain Security Methodology Can DNS responses be tampered with in transit?
Verdict: Delegation is verified but DNS responses are unsigned and could be spoofed.

DNSSEC RFC 4033 §2 Verified Unsigned

DNSSEC not configured - DNS responses are unsigned

Alternative Security: Amazon Route 53 provides enterprise-grade DNS with DDoS protection and monitoring.
Amazon Route 53 (enterprise DNS with DDoS protection), NS1 (IBM) (secondary/backup DNS), CAA records (certificate issuance control)

NS Delegation Verified

8 nameserver(s) configured

Nameservers: dns1.p08.nsone.net dns2.p08.nsone.net dns3.p08.nsone.net dns4.p08.nsone.net ns-1283.awsdns-32.org ns-1707.awsdns-21.co.uk ns-421.awsdns-52.com ns-520.awsdns-01.net
Multi-Resolver Verification Recon: Consensus reached - 4 resolvers (Cloudflare, Google, Quad9, OpenDNS, DNS4EU) agree on DNS records
Traffic & Routing Where does this domain's traffic actually terminate?

AIPv4 Address

140.82.113.4
Where the domain points for web traffic

AAAAIPv6 Address

No AAAA records
IPv6 not configured

MXMail Servers

1 aspmx.l.google.com.
10 alt4.aspmx.l.google.com.
5 alt2.aspmx.l.google.com.
5 alt1.aspmx.l.google.com.
10 alt3.aspmx.l.google.com.
Priority + mail server for email delivery
Google Workspace

SRVServices

_sipfederationtls._tcp: 10 1 5061 sipfed.online.lync.com.
SIP, XMPP, or other service endpoints
Web: Reachable (1 IPv4, 0 IPv6) Mail: 5 servers Services: 1 endpoint
Subdomain Discovery RFC 6962 Recon LIVE What subdomains and infrastructure are exposed in certificate logs? Showing 0 of 126 discovered
How did we find these?
Certificate Transparency Logs Unavailable The results below are from DNS probing only and may be significantly incomplete. CT logs typically reveal hundreds or thousands of additional subdomains via certificate issuance history (RFC 6962).
Re-Analyze to Retry CT Lookup
985 certificates analyzed 56 current 70 expired 38 CNAMEs 2 discovered via CNAME 4 providers identified Source: Certificate Transparency Logs + DNS Probing
Combines CT log certificates (RFC 6962) with DNS probing of common service names. Does not include internal-only names or uncommon subdomain prefixes.
Wildcard certificate detected: *.github.com Active 0 cert
No explicit SANs found on wildcard certificates. Subdomains covered by this wildcard won't appear individually in CT logs (RFC 6962).
DNS probing and CNAME chain traversal were used to discover additional subdomains below.
Third-party services detected via CNAME:
AWS (Cloud) Azure (Cloud) Fastly (CDN) GitHub Pages (Website)
Subdomain Source Status Provider / CNAME Certificates First Seen Issuer(s)
blog.github.com DNS Current GitHub Pages Website 0 — —
hubspot.github.com DNS Current GitHub Pages Website 0 — —
f.cloud.github.com CT Log Current Fastly CDN 454 2011-11-23 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA, GlobalSign Atlas R3 DV TLS CA 2020
vpn-ca.iad.github.com CT Log Current GitHub Pages Website 19 2017-01-13 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1, Sectigo Public Server Authentication CA DV R36
examregistration-api.github.com CT Log Current Azure Cloud 18 2024-01-24 GeoTrust Global TLS RSA4096 SHA256 2022 CA1, Sectigo Public Server Authentication CA DV R36
examadmin-uat.github.com CT Log Current Azure Cloud 14 2025-01-31 GeoTrust Global TLS RSA4096 SHA256 2022 CA1, Sectigo Public Server Authentication CA DV R36
import2.github.com CT Log Current AWS Cloud 12 2019-09-30 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
importer2.github.com CT Log Current AWS Cloud 12 2019-09-30 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
porter2.github.com CT Log Current AWS Cloud 12 2019-09-30 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
examregistration-uat-api.github.com CT Log Current Azure Cloud 11 2024-09-05 GeoTrust Global TLS RSA4096 SHA256 2022 CA1, Sectigo Public Server Authentication CA DV R36
examadmin.github.com CT Log Current Azure Cloud 10 2025-01-31 GeoTrust Global TLS RSA4096 SHA256 2022 CA1, Sectigo Public Server Authentication CA DV R36
asset-generator.github.com CT Log Current GitHub Pages Website 2 2026-01-08 R13
bug-bash.github.com CT Log Current GitHub Pages Website 2 2026-01-07 R12
ducky.github.com CT Log Current GitHub Pages Website 2 2025-12-16 R12
livesend.github.com CT Log Current Azure Cloud 2 2026-02-07 R13
model-launchkit.github.com CT Log Current GitHub Pages Website 2 2026-01-20 R13
mona-arcade.github.com CT Log Current GitHub Pages Website 2 2025-12-12 R12
forms.github.com DNS Current GitHub Pages Website 0 — —
github.github.com DNS Current GitHub Pages Website 0 — —
training.github.com DNS Current GitHub Pages Website 0 — —
www.github.com CT Log Current github.com 71 2011-05-27 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert High Assurance CA-3, DigiCert High Assurance EV CA-1
smtp.github.com Wildcard CT Log Current — 44 2017-03-21 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
support.enterprise.github.com CT Log Current redirect.github.com 18 2012-03-21 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
api.security.github.com CT Log Current glb-db52c2cf8be544.github.com 9 2019-11-12 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
m.communication.github.com CT Log Current mscom-mkt-prod22-lb.campaign.adobe.com 4 2023-07-20 DigiCert Global G2 TLS RSA SHA256 2020 CA1
www.communication.github.com CT Log Current — 3 2024-05-19 DigiCert Global G2 TLS RSA SHA256 2020 CA1
api.mcp.github.com CT Log Current glb-db52c2cf8be544.github.com 1 2025-08-22 DigiCert Global G2 TLS RSA SHA256 2020 CA1
admin.github.com DNS Current glb-2a3c35-public-internal.githubapp.com 0 — —
api.github.com DNS Current — 0 — —
autodiscover.github.com DNS Current redirect.github.com 0 — —
ns1.github.com DNS Current — 0 — —
ns2.github.com DNS Current — 0 — —
shop.github.com DNS Current github.com 0 — —
ssh.github.com DNS Current — 0 — —
support.github.com DNS Current — 0 — —
teams.github.com DNS Current glb-db52c2cf8be544.github.com 0 — —
test.github.com DNS Current — 0 — —
glb-db52c2cf8be544.github.com CNAME Current — 0 — —
raw-origin.github.com CNAME Current — 0 — —
examregistration.github.com CT Log Current redirect.github.com 28 2021-08-31 GeoTrust Global TLS RSA4096 SHA256 2022 CA1, GeoTrust TLS DV RSA Mixed SHA256 2020 CA-1
pkg.github.com Wildcard CT Log Current — 28 2019-04-26 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
registry.github.com Wildcard CT Log Current — 28 2017-01-16 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
review-lab.github.com CT Log Current — 28 2017-05-05 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
octocaptcha.review-lab.github.com Wildcard CT Log Current — 8 2024-07-03 Sectigo Public Server Authentication CA DV R36, Sectigo RSA Domain Validation Secure Server CA
communication.github.com CT Log Current communication.github.com.cname.campaign.adobe.com 7 2023-07-20 DigiCert Global G2 TLS RSA SHA256 2020 CA1
emails.github.com CT Log Current mkto-sj180011.com 6 2023-09-05 DigiCert Global G2 TLS RSA SHA256 2020 CA1, Sectigo Public Server Authentication CA DV R36, Sectigo RSA Domain Validation Secure Server CA
garage.github.com CT Log Current — 5 2023-11-15 DigiCert Global G2 TLS RSA SHA256 2020 CA1, Sectigo Public Server Authentication CA DV R36, Sectigo RSA Domain Validation Secure Server CA
gist.github.com CT Log Current github.com 5 2023-11-15 DigiCert Global G2 TLS RSA SHA256 2020 CA1, Sectigo Public Server Authentication CA DV R36, Sectigo RSA Domain Validation Secure Server CA
ws.support.github.com CT Log Current — 5 2022-10-21 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert TLS RSA SHA256 2020 CA1, Sectigo RSA Domain Validation Secure Server CA
mailing.github.com CT Log Current — 4 2025-03-10 Sectigo Public Server Authentication CA DV R36, Sectigo RSA Domain Validation Secure Server CA
res.communication.github.com CT Log Current mscom-mkt-prod22-lb.campaign.adobe.com 4 2023-07-20 DigiCert Global G2 TLS RSA SHA256 2020 CA1
t.communication.github.com CT Log Current mscom-mkt-prod22-lb.campaign.adobe.com 4 2023-07-20 DigiCert Global G2 TLS RSA SHA256 2020 CA1
launch.github.com DNS Current github.com 0 — —
next.github.com DNS Current redirect.github.com 0 — —
redirect.github.com DNS Current — 0 — —
wiki.github.com DNS Current redirect.github.com 0 — —
help.github.com CT Log Expired — 7 2012-03-28 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
status.github.com CT Log Expired — 6 2012-01-29 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
www.skyline.github.com CT Log Expired — 6 2021-02-12 DigiCert TLS RSA SHA256 2020 CA1
api.stars.github.com CT Log Expired — 5 2020-09-03 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
cloud.github.com CT Log Expired — 5 2014-06-20 DigiCert SHA2 High Assurance Server CA
jira.github.com CT Log Expired — 5 2018-10-05 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
www.smtp.github.com CT Log Expired — 4 2024-02-02 Sectigo RSA Domain Validation Secure Server CA
docs.github.com CT Log Expired — 3 2019-11-25 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1, GeoTrust TLS DV RSA Mixed SHA256 2020 CA-1
www.api.security.github.com CT Log Expired — 3 2021-10-20 DigiCert TLS RSA SHA256 2020 CA1
www.render-lab.github.com CT Log Expired — 3 2020-04-16 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
www.support.enterprise.github.com CT Log Expired — 3 2021-11-04 DigiCert TLS RSA SHA256 2020 CA1
id.github.com CT Log Expired — 2 2013-06-07 DigiCert High Assurance CA-3
www.api.stars.github.com CT Log Expired — 2 2021-09-06 DigiCert TLS RSA SHA256 2020 CA1
www.graphql-stage.github.com CT Log Expired — 2 2020-03-11 DigiCert SHA2 High Assurance Server CA
www.graphql.github.com CT Log Expired — 2 2020-03-11 DigiCert SHA2 High Assurance Server CA
www.jira.github.com CT Log Expired — 1 2021-09-23 DigiCert TLS RSA SHA256 2020 CA1
www.maintainers.github.com CT Log Expired — 1 2020-02-20 DigiCert SHA2 High Assurance Server CA
www.partnerportal.github.com CT Log Expired — 1 2022-10-04 DigiCert TLS RSA SHA256 2020 CA1
www.visualstudio.github.com CT Log Expired — 1 2022-04-14 DigiCert TLS RSA SHA256 2020 CA1
www.ws.support.github.com CT Log Expired — 1 2022-10-21 DigiCert TLS RSA SHA256 2020 CA1
raw.github.com CT Log Expired — 56 2011-11-23 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
examregistration-uat.github.com CT Log Expired — 8 2024-09-05 GeoTrust Global TLS RSA4096 SHA256 2022 CA1
mac-installer.github.com CT Log Expired — 8 2015-10-14 DigiCert SHA2 High Assurance Server CA
education.github.com CT Log Expired — 7 2013-12-21 DigiCert SHA2 High Assurance Server CA
jobs.github.com CT Log Expired — 7 2012-01-06 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
skyline.github.com CT Log Expired — 7 2021-02-12 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert TLS RSA SHA256 2020 CA1
visualstudio.github.com CT Log Expired — 7 2015-04-14 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
branch.github.com Wildcard CT Log Expired — 6 2014-04-09 DigiCert SHA2 High Assurance Server CA
classroom.github.com CT Log Expired — 6 2015-09-07 DigiCert SHA2 High Assurance Server CA
community.github.com CT Log Expired — 6 2013-07-26 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
enterprise.github.com CT Log Expired — 6 2011-10-30 DigiCert High Assurance CA-3, DigiCert SHA2 Extended Validation Server CA, DigiCert SHA2 High Assurance Server CA
import.github.com CT Log Expired — 6 2016-07-08 DigiCert SHA2 High Assurance Server CA
porter.github.com CT Log Expired — 6 2016-07-08 DigiCert SHA2 High Assurance Server CA
proxima-review-lab.github.com CT Log Expired — 6 2023-01-05 DigiCert Global G2 TLS RSA SHA256 2020 CA1, DigiCert TLS RSA SHA256 2020 CA1
rs.github.com CT Log Expired — 6 2011-06-30 DigiCert High Assurance CA-3, DigiCert SHA2 High Assurance Server CA
cla.github.com CT Log Expired — 5 2015-02-05 DigiCert SHA2 High Assurance Server CA
edu.github.com CT Log Expired — 5 2014-04-17 DigiCert SHA2 High Assurance Server CA
lab.github.com CT Log Expired — 4 2018-04-11 DigiCert SHA2 High Assurance Server CA
render-lab.github.com CT Log Expired — 4 2020-04-16 DigiCert SHA2 High Assurance Server CA, DigiCert TLS RSA SHA256 2020 CA1
stg.github.com Wildcard CT Log Expired — 4 2010-10-28 DigiCert High Assurance CA-3, Go Daddy Secure Certification Authority
maintainers.github.com CT Log Expired — 3 2017-02-10 DigiCert SHA2 High Assurance Server CA
styleguide.github.com CT Log Expired — 3 2017-08-23 DigiCert SHA2 High Assurance Server CA
talks.github.com CT Log Expired — 3 2014-06-12 DigiCert SHA2 High Assurance Server CA
vscode-auth.github.com CT Log Expired — 3 2018-09-17 DigiCert SHA2 High Assurance Server CA
codespaces-dev.github.com Wildcard CT Log Expired — 2 2020-04-15 DigiCert SHA2 High Assurance Server CA
codespaces-ppe.github.com Wildcard CT Log Expired — 2 2020-04-15 DigiCert SHA2 High Assurance Server CA
Showing 102 of 126 discovered subdomains, curated by security relevance. Multiple cooperative discovery methods — including CT logs (RFC 6962), DNS probing, and CNAME chain traversal — feed into a unified view. Well-known service names (mail, vpn, api, sso, admin, etc.), DNS-resolving hosts, and subdomains with the most certificate activity are prioritized. 70 expired-certificate-only subdomains included where relevant. Export Full Recon (CSV)
Δ No Propagation Issues: All DNS records are synchronized between resolver and authoritative nameserver.
DNS Intelligence What does DNS look like right now — and what changed over time?
DNS Evidence Diff Side-by-side comparison
Resolver Records (Public DNS cache)
Authoritative Records (Source of truth)
A 1 / 0 records
140.82.113.4
—
AAAA 0 / 0 records
No records
No records
CAA RFC 8659 §4 7 / 0 records
0 issue "globalsign.com"
—
0 issuewild "letsencrypt.org"
—
0 issuewild "digicert.com"
—
0 issue "digicert.com"
—
0 issue "letsencrypt.org"
—
0 issuewild "sectigo.com"
—
0 issue "sectigo.com"
—
DMARC _dmarc.github.com RFC 7489 §6.3 1 / 0 records
v=DMARC1; p=reject; pct=100; rua=mailto:dmarc@github.com
—
MTA-STS _mta-sts.github.com RFC 8461 §3 0 / 0 records
No records
No records
MX RFC 5321 5 / 0 records
1 aspmx.l.google.com.
—
10 alt4.aspmx.l.google.com.
—
5 alt2.aspmx.l.google.com.
—
5 alt1.aspmx.l.google.com.
—
10 alt3.aspmx.l.google.com.
—
NS RFC 1035 8 / 0 records
dns3.p08.nsone.net.
—
ns-1707.awsdns-21.co.uk.
—
dns1.p08.nsone.net.
—
ns-1283.awsdns-32.org.
—
ns-421.awsdns-52.com.
—
ns-520.awsdns-01.net.
—
dns2.p08.nsone.net.
—
dns4.p08.nsone.net.
—
SOA RFC 1035 1 / 0 records
ns-1707.awsdns-21.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
—
TLS-RPT _smtp._tls.github.com RFC 8460 §3 0 / 0 records
No records
No records
TXT RFC 7208 §4 19 / 0 records
v=spf1 ip4:192.30.252.0/22 include:_netblocks.google.com include:_netblocks2.google.com include:_netblocks3.google.com include:spf.protection.outlook.com include:mail.zendesk.com include:_spf.salesforce.com include:servers.mcsv.net include:mktomail.com ip4:62.253.227.114 ip4:166.78.69.169 ip4:166.78.69.170 ip4:166.78.71.131 ip4:167.89.101.2 ip4:167.89.101.192/28 ip4:192.254.112.60 ip4:192.254.112.98/31 ip4:192.254.113.10 ip4:192.254.113.101 ip4:192.254.114.176 ~all
—
atlassian-domain-verification=jjgw98AKv2aeoYFxiL/VFaoyPkn3undEssTRuMg6C/3Fp/iqhkV4HVV7WjYlVeF8
—
shopify-verification-code=t1YPwcmvnxZyBycaCpk1MPyWoFs72o
—
stripe-verification=f88ef17321660a01bab1660454192e014defa29ba7b8de9633c69d6b4912217f
—
TAILSCALE-xOzoDvFUzZr5YYVCQFuD
—
MS=ms58704441
—
google-site-verification=82Le34Flgtd15ojYhHlGF_6g72muSjamlMVThBOJpks
—
krisp-domain-verification=ZlyiK7XLhnaoUQb2hpak1PLY7dFkl1WE
—
MS=ms44452932
—
adobe-idp-site-verification=b92c9e999aef825edc36e0a3d847d2dbad5b2fc0e05c79ddd7a16139b48ecf4b
—
loom-site-verification=f3787154f1154b7880e720a511ea664d
—
apple-domain-verification=RyQhdzTl6Z6x8ZP4
—
calendly-site-verification=at0DQARi7IZvJtXQAWhMqpmIzpvoBNF7aam5VKKxP
—
miro-verification=d2e174fdb00c71e0bcf58f8e58c3da2dd80dcfa9
—
facebook-domain-verification=39xu4jzl7roi7x0n93ldkxjiaarx50
—
docusign=087098e3-3d46-47b7-9b4e-8a23028154cd
—
google-site-verification=UTM-3akMgubp6tQtgEuAkYNYLyYAvpTnnSrDMWoDR3o
—
jamf-site-verification=XtaPNIYghF_e_xRDI8CjgQ
—
MS=6BF03E6AF5CB689E315FB6199603BABF2C88D805
—
DNS History Timeline BETA
Your key is sent directly to SecurityTrails and is never stored on our servers. Get an API key
DNS History Timeline BETA

When was a record added, removed, or changed — and could that change be the problem?

Analyze Another Domain

Confirm Your Email Configuration

This tool analyzes DNS records, but to verify actual email delivery, send a test email to Red Sift Investigate. Their tool shows exactly how your emails arrive, including SPF/DKIM/DMARC pass/fail results in the headers.

DATA FRESHNESS & METHODOLOGY

All security-critical records (SPF, DMARC, DKIM, DANE/TLSA, DNSSEC, MTA-STS, TLS-RPT, BIMI, CAA) are queried live from authoritative nameservers and cross-referenced against 5 independent public DNS resolvers (Cloudflare, Google, Quad9, OpenDNS, DNS4EU) at the time of each analysis. No security verdict uses cached data.

Registrar data (RDAP) is cached for up to 24 hours because domain ownership and registration details change infrequently. Certificate Transparency logs (subdomain discovery via RFC 6962) are cached for 1 hour because CT entries are append-only historical records. Sections using cached data are marked with a CACHED badge; live queries show LIVE.

Subdomain curation: 126 subdomains were discovered — the most security-relevant are displayed, prioritized by: well-known service names (mail, vpn, api, sso, admin, etc.), DNS-resolving hosts, and subdomains with the most certificate activity. CNAME chain resolution and provider identification run on the curated set for accuracy. The complete list is available via CSV export.

Intelligence Sources

This analysis used 4 DNS resolvers (consensus), reverse DNS (PTR), Team Cymru (ASN attribution), IANA RDAP (registrar), crt.sh (CT logs), and SMTP probing (transport). All using open-standard protocols.

Full List
Verify Report Integrity SHA-3-512 Has this report been altered since generation? Verify below

This cryptographic hash seals the analysis data, domain, timestamp, and tool version into a tamper-evident fingerprint. Any modification to the report data will produce a different hash. This is distinct from the posture hash (used for drift detection) — the integrity hash uniquely identifies this specific report instance.

87ba213d08fc917bd4a2108c6a79d459a972ba43de524f773fd1acc4b5d06821865de7ebc71ff751947e06eb47db209a37f82ac27c6b46f29b495091cada7dc5
Evaluations reference 12 RFCs. Methods are reproducible using the verification commands provided. Results reflect DNS state at 9 Feb 2026, 05:00 UTC.
Download Raw Intelligence Download Checksum (.sha3)

Download the intelligence dump and verify its integrity, like you would a Kali ISO or any critical artifact. The SHA-3-512 checksum covers every byte of the download — deterministic serialization ensures identical hashes across downloads.

After downloading, verify with any of these commands:

Tip: cd ~/Downloads first (or wherever you saved the files).

OpenSSL + Sidecar (macOS, Linux, WSL) 
cat dns-intelligence-github.com.json.sha3 && echo '---' && openssl dgst -sha3-512 dns-intelligence-github.com.json
Python 3 (cross-platform) 
python3 -c "import hashlib; print(hashlib.sha3_512(open('dns-intelligence-github.com.json','rb').read()).hexdigest())"
sha3sum (coreutils 9+) 
sha3sum -a 512 dns-intelligence-github.com.json
Compare the output against the .sha3 file or the checksum API at /api/analysis/455/checksum. Hash algorithm: SHA-3-512 (Keccak, NIST FIPS 202).

Every finding in this report is backed by DNS queries you can run yourself. These vetted one-liners reproduce the exact checks used to build this report for github.com. Our analysis adds multi-resolver consensus, RFC-based evaluation, and cross-referencing — but the underlying data is always independently verifiable. We are intelligence analysts, not gatekeepers.

DNS Records

Query A records (IPv4) RFC 1035 
dig +noall +answer github.com A
Query AAAA records (IPv6) RFC 1035 
dig +noall +answer github.com AAAA
Query MX records (mail servers) RFC 1035 
dig +noall +answer github.com MX
Query NS records (nameservers) RFC 1035 
dig +noall +answer github.com NS
Query TXT records RFC 1035 
dig +noall +answer github.com TXT

Email Authentication

Check SPF record RFC 7208 
dig +short github.com TXT | grep -i spf
Check DMARC policy RFC 7489 
dig +short _dmarc.github.com TXT
Check DKIM key for selector 'cm' RFC 6376 
dig +short cm._domainkey.github.com TXT
Check DKIM key for selector 'google' RFC 6376 
dig +short google._domainkey.github.com TXT
Check DKIM key for selector 'k1' RFC 6376 
dig +short k1._domainkey.github.com TXT
Check DKIM key for selector 'k2' RFC 6376 
dig +short k2._domainkey.github.com TXT
Check DKIM key for selector 's1' RFC 6376 
dig +short s1._domainkey.github.com TXT
Check DKIM key for selector 's2' RFC 6376 
dig +short s2._domainkey.github.com TXT
Check DKIM key for selector 'zendesk1' RFC 6376 
dig +short zendesk1._domainkey.github.com TXT
Check DKIM key for selector 'zendesk2' RFC 6376 
dig +short zendesk2._domainkey.github.com TXT

Domain Security

Check DNSSEC DNSKEY records RFC 4035 
dig +dnssec +noall +answer github.com DNSKEY
Check DNSSEC DS records RFC 4035 
dig +noall +answer github.com DS
Validate DNSSEC chain (requires DNSSEC-validating resolver) RFC 4035 
dig +dnssec +cd github.com A @1.1.1.1

Transport Security

Check TLSA record for aspmx.l.google.com RFC 7672 
dig +noall +answer _25._tcp.aspmx.l.google.com TLSA
Check TLSA record for alt4.aspmx.l.google.com RFC 7672 
dig +noall +answer _25._tcp.alt4.aspmx.l.google.com TLSA
Check TLSA record for alt2.aspmx.l.google.com RFC 7672 
dig +noall +answer _25._tcp.alt2.aspmx.l.google.com TLSA
Check TLSA record for alt1.aspmx.l.google.com RFC 7672 
dig +noall +answer _25._tcp.alt1.aspmx.l.google.com TLSA
Check TLSA record for alt3.aspmx.l.google.com RFC 7672 
dig +noall +answer _25._tcp.alt3.aspmx.l.google.com TLSA
Verify TLS certificate on primary MX (aspmx.l.google.com) RFC 6698 
openssl s_client -starttls smtp -connect aspmx.l.google.com:25 -servername aspmx.l.google.com 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record RFC 8461 
dig +short _mta-sts.github.com TXT
Fetch MTA-STS policy file RFC 8461 
curl -sL https://mta-sts.github.com/.well-known/mta-sts.txt
Check TLS-RPT record RFC 8460 
dig +short _smtp._tls.github.com TXT

Brand & Trust

Check BIMI record BIMI Draft 
dig +short default._bimi.github.com TXT
Check CAA records (certificate authority authorization) RFC 8659 
dig +noall +answer github.com CAA

DNS Records

Check HTTPS/SVCB records RFC 9460 
dig +noall +answer github.com HTTPS

Domain Security

Check CDS/CDNSKEY automation records RFC 7344 
dig +noall +answer github.com CDS

Infrastructure Intelligence

RDAP domain registration lookup RFC 9083 
curl -sL 'https://rdap.org/domain/github.com' | python3 -m json.tool | head -50

Transport Security

Test STARTTLS on primary MX (aspmx.l.google.com) RFC 3207 
openssl s_client -starttls smtp -connect aspmx.l.google.com:25 -servername aspmx.l.google.com </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs RFC 6962 
curl -s 'https://crt.sh/?q=%25.github.com&output=json' | python3 -c "import json,sys; [print(e['name_value']) for e in json.load(sys.stdin)]" | sort -u | head -20
Check security.txt RFC 9116 
curl -sL https://github.com/.well-known/security.txt | head -20

AI Surface

Check for llms.txt 
curl -sI https://github.com/llms.txt | head -5
Check robots.txt for AI crawler rules 
curl -s https://github.com/robots.txt | grep -i -E 'GPTBot|ChatGPT|Claude|Anthropic|Google-Extended|CCBot|PerplexityBot'

Infrastructure Intelligence

ASN lookup for 140.82.113.4 (Team Cymru) 
dig +short 4.113.82.140.origin.asn.cymru.com TXT
Commands use dig, openssl, and curl — standard tools available on macOS, Linux, and WSL. Results may vary slightly due to DNS propagation timing and resolver caching.
Intelligence Confidence Audit Engine Verified · 9/9 Evaluated
How confident are these results? Each protocol is independently verified against RFC standards. No self-awarded badges.
SPF
Verified 4853 runs
DKIM
Verified 4672 runs
DMARC
Verified 4837 runs
DANE/TLSA
Verified 4656 runs
DNSSEC
Verified 4834 runs
BIMI
Verified 4671 runs
MTA-STS
Verified 4674 runs
TLS-RPT
Verified 4676 runs
CAA
Verified 4668 runs
Maturity: Development → Verified → Consistent → Gold → Gold Master

Appendix: Verification Commands

The core DNS queries behind this report can be independently verified using these standard terminal commands (dig, openssl, curl). DNS Tool adds multi-resolver consensus, RFC-based evaluation, and cross-referencing on top of the raw data shown here.

DNS Records

Query A records (IPv4) (RFC 1035) 
dig +noall +answer github.com A
Query AAAA records (IPv6) (RFC 1035) 
dig +noall +answer github.com AAAA
Query MX records (mail servers) (RFC 1035) 
dig +noall +answer github.com MX
Query NS records (nameservers) (RFC 1035) 
dig +noall +answer github.com NS
Query TXT records (RFC 1035) 
dig +noall +answer github.com TXT

Email Authentication

Check SPF record (RFC 7208) 
dig +short github.com TXT | grep -i spf
Check DMARC policy (RFC 7489) 
dig +short _dmarc.github.com TXT
Check DKIM key for selector 'cm' (RFC 6376) 
dig +short cm._domainkey.github.com TXT
Check DKIM key for selector 'google' (RFC 6376) 
dig +short google._domainkey.github.com TXT
Check DKIM key for selector 'k1' (RFC 6376) 
dig +short k1._domainkey.github.com TXT
Check DKIM key for selector 'k2' (RFC 6376) 
dig +short k2._domainkey.github.com TXT
Check DKIM key for selector 's1' (RFC 6376) 
dig +short s1._domainkey.github.com TXT
Check DKIM key for selector 's2' (RFC 6376) 
dig +short s2._domainkey.github.com TXT
Check DKIM key for selector 'zendesk1' (RFC 6376) 
dig +short zendesk1._domainkey.github.com TXT
Check DKIM key for selector 'zendesk2' (RFC 6376) 
dig +short zendesk2._domainkey.github.com TXT

Domain Security

Check DNSSEC DNSKEY records (RFC 4035) 
dig +dnssec +noall +answer github.com DNSKEY
Check DNSSEC DS records (RFC 4035) 
dig +noall +answer github.com DS
Validate DNSSEC chain (requires DNSSEC-validating resolver) (RFC 4035) 
dig +dnssec +cd github.com A @1.1.1.1

Transport Security

Check TLSA record for aspmx.l.google.com (RFC 7672) 
dig +noall +answer _25._tcp.aspmx.l.google.com TLSA
Check TLSA record for alt4.aspmx.l.google.com (RFC 7672) 
dig +noall +answer _25._tcp.alt4.aspmx.l.google.com TLSA
Check TLSA record for alt2.aspmx.l.google.com (RFC 7672) 
dig +noall +answer _25._tcp.alt2.aspmx.l.google.com TLSA
Check TLSA record for alt1.aspmx.l.google.com (RFC 7672) 
dig +noall +answer _25._tcp.alt1.aspmx.l.google.com TLSA
Check TLSA record for alt3.aspmx.l.google.com (RFC 7672) 
dig +noall +answer _25._tcp.alt3.aspmx.l.google.com TLSA
Verify TLS certificate on primary MX (aspmx.l.google.com) (RFC 6698) 
openssl s_client -starttls smtp -connect aspmx.l.google.com:25 -servername aspmx.l.google.com 2>/dev/null | openssl x509 -noout -subject -dates
Check MTA-STS DNS record (RFC 8461) 
dig +short _mta-sts.github.com TXT
Fetch MTA-STS policy file (RFC 8461) 
curl -sL https://mta-sts.github.com/.well-known/mta-sts.txt
Check TLS-RPT record (RFC 8460) 
dig +short _smtp._tls.github.com TXT

Brand & Trust

Check BIMI record (BIMI Draft) 
dig +short default._bimi.github.com TXT
Check CAA records (certificate authority authorization) (RFC 8659) 
dig +noall +answer github.com CAA

DNS Records

Check HTTPS/SVCB records (RFC 9460) 
dig +noall +answer github.com HTTPS

Domain Security

Check CDS/CDNSKEY automation records (RFC 7344) 
dig +noall +answer github.com CDS

Infrastructure Intelligence

RDAP domain registration lookup (RFC 9083) 
curl -sL 'https://rdap.org/domain/github.com' | python3 -m json.tool | head -50

Transport Security

Test STARTTLS on primary MX (aspmx.l.google.com) (RFC 3207) 
openssl s_client -starttls smtp -connect aspmx.l.google.com:25 -servername aspmx.l.google.com </dev/null 2>/dev/null | head -5

Infrastructure Intelligence

Search Certificate Transparency logs (RFC 6962) 
curl -s 'https://crt.sh/?q=%25.github.com&output=json' | python3 -c "import json,sys; [print(e['name_value']) for e in json.load(sys.stdin)]" | sort -u | head -20
Check security.txt (RFC 9116) 
curl -sL https://github.com/.well-known/security.txt | head -20

AI Surface

Check for llms.txt 
curl -sI https://github.com/llms.txt | head -5
Check robots.txt for AI crawler rules 
curl -s https://github.com/robots.txt | grep -i -E 'GPTBot|ChatGPT|Claude|Anthropic|Google-Extended|CCBot|PerplexityBot'

Infrastructure Intelligence

ASN lookup for 140.82.113.4 (Team Cymru) 
dig +short 4.113.82.140.origin.asn.cymru.com TXT
Running Multi-Source Intelligence Audit

github.com

0s
DNS records — Cloudflare, Google, Quad9, OpenDNS, DNS4EU
Email auth — SPF, DMARC, DKIM selectors
DNSSEC chain of trust & DANE/TLSA
Certificate Transparency & subdomain discovery
SMTP transport & STARTTLS verification
MTA-STS, TLS-RPT, BIMI, CAA
Registrar & infrastructure analysis
Intelligence Classification & Interpretation

Every result includes terminal commands you can run to independently verify the underlying data. No proprietary magic.