DNS Gurus
Cached · just now
76/100 SECURITY SCORE

Certificate Information

Subject
CN=tools4teachers.com
Issuer
C=US, O=Let's Encrypt, CN=R12
Valid From
January 31, 2026
Valid Until
May 01, 2026 81 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
56:41:99:EC:8A:AF:7C:C2:74:2C:91:60:77:AF:27:C1:E4:5D:B5:30:C9:44:E4:3C:E8:05:14:58:3D:24:C0:49
Alternative Names
90 domains

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Missing
Not configured
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • • Add Strict-Transport-Security header with max-age of at least 1 year
  • • Add Content-Security-Policy header to prevent XSS attacks
  • • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
  • • Add X-Content-Type-Options: nosniff
  • • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
  • • Consider adding Permissions-Policy to control browser features

CAA Records (Certificate Authority Authorization)

CAA Records
Not Configured (Any CA can issue certificates)
CAA Issues
  • • No CAA records configured - any CA can issue certificates
Recommendations
  • • Implement CAA records to restrict which CAs can issue certificates for your domain
  • • This adds an extra layer of security against unauthorized certificate issuance
  • • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
  • • Consider adding 'iodef' record to receive security incident reports

Subject Alternative Names

90 domains
querubin.com *.querubin.com *.webdisk.querubin.com

Other domains in certificate

*.cms.coopz.io coopz.io *.coopz.io *.dddd.coopz.io *.ww25.coopz.io *.www.coopz.io
*.blog.hostinet.com.br *.cliente.hostinet.com.br *.cpanel.hostinet.com.br *.cpcalendars.hostinet.com.br *.hospedado.hostinet.com.br hostinet.com.br *.hostinet.com.br *.live.hostinet.com.br *.server.hostinet.com.br *.server22.hostinet.com.br *.teste.hostinet.com.br *.vps-8614883.hostinet.com.br *.webmail.hostinet.com.br
*.dash.mattsmithpt.com *.ftp.mattsmithpt.com *.mail.mattsmithpt.com mattsmithpt.com *.mattsmithpt.com *.mx.mattsmithpt.com *.owa.mattsmithpt.com *.preprod.mattsmithpt.com *.superset.mattsmithpt.com *.ww38.mattsmithpt.com
*.a.qr.id *.aji.qr.id *.al-irsyad.qr.id *.alsofwah.qr.id *.aminef.qr.id *.apjil.qr.id *.apsi.qr.id *.aswandi.qr.id *.ban-sm.qr.id *.bansm.qr.id *.bloggerindonesia.qr.id *.cfg4.qr.id *.csrc.qr.id *.damandiri.qr.id *.dana.qr.id *.dirgantara-lapan.qr.id *.e.qr.id *.elsom.qr.id *.gaikindo.qr.id *.gtzsfdm.qr.id *.ibnukatsir.qr.id *.ikasma2pdg.qr.id *.ispa.qr.id *.k6menaq.qr.id *.kadin-indonesia.qr.id *.kaltimprov.qr.id *.kehati.qr.id *.kemkes.qr.id *.keuangan.qr.id *.kopertis6.qr.id *.mec.qr.id *.media-islam.qr.id *.milanisti.qr.id *.muhammadiyah.qr.id *.muslim.qr.id *.nurmal.qr.id *.nyem.qr.id *.olimpiadeagpaii.qr.id *.original.qr.id *.penabulu.qr.id *.perbarindo.qr.id *.pssi.qr.id *.puskur.qr.id *.qmim.qr.id qr.id *.qr.id *.rawdata.qr.id *.sekolahdesa.qr.id *.smart.qr.id *.ub.qr.id *.wildcard.qr.id *.xn--dec-mma.qr.id *.y.qr.id *.ymh.qr.id *.ysattegal.qr.id
*.crisp.tools4teachers.com tools4teachers.com *.tools4teachers.com