Identity
31
D
krebsonsecurity.com
Posture Score: 65/100
Scanned May 8, 2026 at 7:51 AM UTC
Attack Surface
91
Reputation
73
Identity Findings
Permissive SPF qualifier: ?all
The ?all qualifier provides no guidance on unauthorized senders.
💡 Change to "-all" (hard fail) or "~all" (soft fail).
No DMARC record found
The domain has no DMARC record, providing no policy for handling unauthenticated email.
💡 Publish a DMARC TXT record at _dmarc.krebsonsecurity.com (e.g. "v=DMARC1; p=reject; rua=mailto:dmarc@krebsonsecurity.com").
No MX records found
The domain has no MX records and cannot receive email.
💡 Publish MX records pointing to your mail server(s).
No DKIM records found
No DKIM records were found for any common selector. Email may not be authenticated.
💡 Configure DKIM signing and publish the public key at <selector>._domainkey.krebsonsecurity.com
No MTA-STS record found
Without MTA-STS, mail transport encryption cannot be enforced and is vulnerable to downgrade attacks.
💡 Publish a _mta-sts TXT record and host a policy file at https://mta-sts.krebsonsecurity.com/.well-known/mta-sts.txt
SOA expire value too short
The SOA expire value is 259200s (<604,800s / 7 days). Secondary nameservers may stop serving the zone prematurely.
💡 Increase the SOA expire value to at least 604800 seconds (7 days).
No CAA records found
No CAA records are configured. Any certificate authority can issue certificates for this domain.
💡 Add CAA records to restrict certificate issuance. Example: 0 issue "letsencrypt.org"
No TLS-RPT record found
Without TLS-RPT, you will not receive reports about TLS negotiation failures.
💡 Publish a _smtp._tls TXT record (e.g. "v=TLSRPTv1; rua=mailto:tls-reports@krebsonsecurity.com").
ARC check skipped — no MX records
Cannot assess ARC support without MX records.
Very low TTL on SPF record: 295s
The SPF record has a TTL of 295s or less (below 300s).
💡 Increase the TTL to at least 300 seconds unless frequent changes are expected.
NS TTL mismatch between parent and authoritative zone
The NS record TTL in the parent zone (~7195s) differs significantly from the authoritative zone (~21600s).
💡 Align NS record TTLs between the parent zone delegation and the authoritative zone.
DKIM cryptographic configuration is compliant
No RFC 8301 compliance issues detected in DKIM key configuration.
IPv6 readiness is good
IPv6 records are present and properly configured.
NS delegation is properly configured
All nameservers are responsive, consistent, and properly secured.
DNS responses are consistent across all nameservers
All authoritative nameservers return consistent answers with proper AA flags.
DKIM2 not detected
No DKIM key record with v=2 was found across common selectors. DKIM2 is an emerging standard and not yet widely deployed.
DANE check skipped — no MX records
Cannot check DANE/TLSA without MX records.
No BIMI record found
BIMI is not configured. Your brand logo will not display in supporting email clients.
Open relay check skipped — no MX records
Cannot test for open relay without MX records.
SMTP compliance check skipped — no MX records
Cannot test SMTP compliance without MX records.
Port exposure check skipped — no MX records
Cannot scan ports without MX records.
STARTTLS downgrade check skipped — no MX records
Cannot test STARTTLS without MX records.
RFC 8058 one-click unsubscribe assessment
No DKIM signing detected. RFC 8058 one-click unsubscribe requires DKIM-signed List-Unsubscribe headers.
FCrDNS check skipped — no MX records
Cannot perform FCrDNS without MX records.
SOA record parameters
Serial: 1, Refresh: 21600s, Retry: 3600s, Expire: 259200s, Min TTL: 300s
Attack Surface Findings
Domain enumerability: medium
The domain has moderate enumerability. CT logs and DNS records reveal significant information about the domain structure.
💡 Restrict zone transfers, use NSEC3 instead of NSEC, consider wildcard certificates to reduce CT log exposure, and implement rate limiting on DNS queries.
DNSSEC is not enabled
No DNSKEY or DS records were found. DNS responses are not cryptographically authenticated.
💡 Enable DNSSEC by generating DNSKEY records and publishing DS records at the registrar.
DNS ANY query returns 7 record(s)
The DNS server responds to ANY queries with 7 record(s). The low record count limits amplification risk, but ANY responses still aid reconnaissance.
💡 Configure the DNS server to refuse or minimize ANY query responses per RFC 8482.
No subdomain takeover risks detected
All checked subdomains have valid, responsive targets.
No internal information leakage detected
No non-routable IP addresses or internal references were found in public DNS records.
No email autodiscovery endpoints detected
No Microsoft Autodiscover, Mozilla Autoconfig, or email SRV records were found.
2 subdomain(s) discovered for krebsonsecurity.com
Subdomains were enumerated via Certificate Transparency logs, DNS wordlist brute-forcing, and DNS record analysis.
0 certificate(s) found in CT logs
Certificate Transparency logs contain 0 certificate(s) for krebsonsecurity.com and its subdomains. Each certificate reveals subdomain names.
Reputation Findings
Listed on black.uribl.com
krebsonsecurity.com is listed on blacklist black.uribl.com (response: 127.0.0.1).
💡 Visit the black.uribl.com website to request delisting. Investigate the root cause (compromised account, open relay, spam) before requesting removal.
Missing domain locks: clientDeleteProhibited
Domain krebsonsecurity.com is missing protective locks: clientDeleteProhibited.
💡 Enable clientTransferProhibited and clientDeleteProhibited locks through your registrar to prevent unauthorized transfers or deletions.
Missing Strict-Transport-Security on krebsonsecurity.com
The Strict-Transport-Security header is not set on https://krebsonsecurity.com.
💡 Add the Strict-Transport-Security header with a max-age of at least 31536000 (1 year) and include the includeSubDomains directive.
security.txt present
Found security.txt at https://krebsonsecurity.com/.well-known/security.txt.
TLS certificate valid for 79 days
Certificate for krebsonsecurity.com expires on 2026-07-26.
Certificate issued by WR3
The certificate for krebsonsecurity.com is issued by a third-party CA.
Signature algorithm: rsa-sha256
The certificate for krebsonsecurity.com uses an acceptable signature algorithm.
RSA key: 2048 bits
The certificate for krebsonsecurity.com uses an adequate RSA key of 2048 bits.
SCTs present in certificate
The certificate for krebsonsecurity.com contains Signed Certificate Timestamps.
No weak ciphers detected
No known weak cipher suites detected on krebsonsecurity.com.
Domain valid for 199 days
Domain krebsonsecurity.com expires on 2026-11-23.
No disposable email provider MX records
MX records for krebsonsecurity.com do not match known disposable email provider patterns.
Domain is 6009 days old
Domain krebsonsecurity.com was registered 2009-11-23.
No wildcard MX records
No wildcard MX records detected for krebsonsecurity.com.
Google Safe Browsing DNS check — no flag detected
DNS-based Safe Browsing lookup returned no results. Full verification requires the Google Safe Browsing API key.
No abuse contacts resolved
Could not resolve abuse contact information for MX IPs via abusix.org.
PhishTank — API key required
PhishTank phishing database check requires an API key.
Sender Score — API key required
Sender Score reputation check requires an API key.
Cisco Talos — API key required
Cisco Talos IP reputation check requires an API key.
Could not connect to webmail.krebsonsecurity.com
HTTPS request to https://webmail.krebsonsecurity.com failed or timed out.
WHOIS registration data
Registrar: Tucows Domains Inc. | Created: 2009-11-23 | Expires: 2026-11-23 | Updated: 2017-10-27
WHOIS privacy protection enabled
Domain krebsonsecurity.com has WHOIS privacy/redaction enabled.
Bulletproof Hosting Detection — API key required
Checking IPs against known bulletproof hosting providers requires a threat intelligence API key.
Threat Intelligence Feeds — API key required
Checking domain against threat intelligence feeds requires API keys (e.g., VirusTotal, AbuseIPDB).
Dependency Chains
DMARC Authentication Chain (SPF)
DMARC uses SPF to verify that emails come from authorized servers
SPF Record
SPF record found and configured
→
DMARC Policy
DMARC policy missing
⚠️ DMARC policy is missing. Even with SPF configured, you lack the policy layer that tells receiving servers what to do with authentication failures.
DMARC Authentication Chain (DKIM)
DMARC uses DKIM to verify that emails have not been tampered with
DKIM Signature
DKIM signature missing
→
DMARC Policy
DMARC policy missing
⚠️ DKIM signature is missing. DMARC relies on DKIM to verify email integrity and prevent tampering. Without DKIM, DMARC alignment will fail for cryptographic verification.
Enforced Encryption Chain
MTA-STS enforces TLS encryption to prevent man-in-the-middle attacks
TLS Support
TLS not verified or unsupported
→
MTA-STS Policy
MTA-STS not configured
⚠️ TLS support could not be verified. MTA-STS requires TLS to enforce encrypted connections. Without TLS, MTA-STS cannot function.
Brand Identity Chain
BIMI displays your logo in email clients, but requires DMARC enforcement
DMARC Enforcement
DMARC not enforced (p=none or missing)
→
BIMI Record
BIMI not configured
⚠️ DMARC is not enforced. BIMI requires a DMARC policy of "quarantine" or "reject" to prove you have strong email authentication. Without enforcement, email clients will not display your logo.
TLS Monitoring Chain
TLS-RPT provides reports about TLS connection failures
TLS Support
TLS not verified or unsupported
→
TLS-RPT Reporting
TLS-RPT not configured
⚠️ TLS support could not be verified. TLS-RPT reports on TLS connection failures, but without TLS support, there's nothing to monitor. You need working TLS encryption before TLS-RPT can provide value.
Security Checks
MX Records
✗
SPF Record
✓
DKIM Record
✗
DMARC Policy
✗
BIMI Record
✗
CAA Records
✗
DNSSEC
✗
MTA-STS
✗
TLS-RPT
✗
Embed Badge
Display your domain's security grade on your website or README:
<img src="https://scan.ractermx.com/badge/krebsonsecurity.com.svg" alt="Email Security Grade">
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