4os.dk

📜 Historical scan 2026-06-24 10:21:31  ·  ← Latest scan
⬇ Zone File 📜 Timeline & History ⚡ Scan Now

4os.dk is a .dk domain served by 2 nameservers (ns1.curanet.dk, ns2.curanet.dk). It was registered on 19 March 2009 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 95.166.113.35 is hosted by TDC Holding A/S (AS3292) in Denmark. Mail is handled by 4os-dk.mail.protection.outlook.com. The zone is DNSSEC-signed but currently fails validation, has no DMARC policy and has no IPv6 address. Below are all of its DNS records from this scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.

🖥️ Nameservers#

2 records   90ms

🌍 A Records#

1 records   44ms
IPTTLPTRASNISP / OrgCIDRCountryCity
95.166.113.35 3600s — AS3292 TDC Holding A/S 95.166.64.0/18 🇩🇰 Denmark —

📧 MX Records#

1 records   29ms
PriorityTTLMail ServerIP addressesPTRASN
10 3600s 4os-dk.mail.protection.outlook.com — — —

📧 Autodiscover / Autoconfig#

ServiceCNAME / IP
🔷 Autodiscoverautodiscover.outlook.com → 52.98.149.152
🔶 Autoconfig93.191.155.37

🔷 AAAA Records (IPv6)#

✗ No AAAA records — IPv6 not configured

🔐 HTTPS Records#

✗ No HTTPS RR — no SVCB/HTTPS service binding

🔌 SRV Records#

2 records   114ms
ServicePriorityWeightPortTarget
_autodiscover._tcp 100 1 443 remote.4os.dk
_sipfederationtls._tcp 100 1 5061 sipfed.online.lync.com

📝 TXT Records#

3 records   167ms
TXT Record
_globalsign-domain-verification=xxTTxdBZBDdcmwf1Vq1WUXd2zOngTJkHnTmXMmoVKx
MS=ms99155619
v=spf1 include:spf.protection.outlook.com -all

✉️ SPF#

PolicyRecord (4os.dk)
-all (hard fail) v=spf1 include:spf.protection.outlook.com -all

📨 DMARC#

✗ No DMARC record — mail spoofing not restricted

📬 MTA-STS#

✗ No MTA-STS policy — SMTP TLS not enforced

📈 TLSRPT#

✗ No TLSRPT record — no SMTP TLS failure reporting

📜 CAA Records#

✗ No CAA records — any CA may issue certificates

🧩 Web & zone#

latest probe, not this scan · checked 2026-10-16 16:54:25
www93.191.155.37 (AS48854) (address records, no CNAME)
www vs bare domainDifferent networks
4os.dk: 95.166.113.35 (AS3292)
www.4os.dk: 93.191.155.37 (AS48854)
(all like this)
WildcardYes: any name under the zone resolves
Denial of existenceNSEC3 · 1 iteration · 1-byte salt RFC 9276 recommends 0 iterations and no salt
CDS / CDNSKEYNone 0 CDS, 0 CDNSKEY

🔎 SPF check#

zone-wide SPF report

DNS lookups: 1/10 · policy: -all

No problems found

🔗 TLSA / DANE#

✗ No TLSA records — DANE not configured for HTTPS (_443) or MX (_25)

🔐 DNSSEC#

65ms
CheckResult
Validation Status⚠️ Bogus
AD Flag (resolver validates)✗ Not set
DS Record✓ Found
DNSKEY Record✓ Found
Flagsbroken trust chain resolving '4os.dk/DS/IN': 127.0.0.1#53

🏷️ SOA#

93ms
FieldValue
Serial2021111701
Primary NS (MNAME)ns1.curanet.dk
Responsible (RNAME)hostmaster@curanet.dk
Refresh14400s
Retry3600s
Expire1209600s
Minimum (neg-cache TTL)300s

📋 Registration#

WHOIS fetched 2026-10-20 23:25:44
FieldValue
RegistrarPunktum dk A/S (direct)
Registered2009-03-19
Expires2027-03-31 (161d)

🔗 Same registrant#

0 domains

Other .dk domains whose WHOIS registrant has the same name and postal address. Matched on a keyed hash: the registrant's details are not stored or shown. Covers only domains whose WHOIS we have fetched (refreshed about monthly).

No other domain with this registrant in our WHOIS data yet
📋 WHOIS#

⏱️ Lookup Timing#

NS
90ms
A
44ms
MX
29ms
AAAA
92ms
TXT
167ms
CAA
83ms
HTTPS
40ms
TLSA
466ms
SOA
93ms
MTA-STS
84ms
DNSSEC
65ms
SRV
114ms
Total
957ms

🕐 Scan History#

Scanned AtDurationRecordsDNSSEC
2026-09-30 15:59:13 656ms 2 NS 1 A 1 MX 🔒 Secure
2026-09-24 22:17:17 551ms 2 NS 1 A 1 MX 🔒 Secure
2026-06-27 23:51:25 1420ms 2 NS 1 A 1 MX 🔒 Secure
2026-06-24 10:21:31 shown 957ms 2 NS 1 A 1 MX ⚠️ Bogus
2026-06-22 05:57:38 1684ms 2 NS 1 A 1 MX 🔒 Secure
2026-06-20 00:52:00 881ms 2 NS 1 A 1 MX 🔒 Secure
2026-06-16 13:14:22 1673ms 2 NS 1 A 1 MX 🔒 Secure
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