Check-Host.cc

IP Address IPv4

141.223.197.21

Aggregated from public BGP, CT logs, our scan layer, honeypots and global probes.

Run a live full scan of 141.223.197.21

On-demand: ports, banners, TLS, tech-stack, subdomains and origin/IP-leak detection. Results are shared publicly for everyone to link to.

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ASN
AS3784
Click for details
Country
KR
South Korea
Reverse DNS
sbi.postech.ac.kr
PTR
Open Ports
3
Last scan

Autonomous System

ASN
AS Name
AS Type
RIR
APNIC
Allocated
2002-08-01
Allocation status
Allocated

Geolocation

Country
KR · South Korea
Continent
Asia
Source
MaxMind GeoLite2

Reverse DNS

Last seen
2026-07-27 16:32:50

Network

RPKI

Open Ports

Port Proto Service Server Last seen
80 tcp http Apache 2026-05-26 20:48:29.000
443 tcp https Apache 2026-07-27 16:32:41.000
5060 tcp sip 2026-06-20 05:24:58.000

TLS Certificates

Port 443 db21ad2ca856…
Subject: *.postech.ac.kr
Issuer: Thawte TLS RSA CA G1
SANs: *.postech.ac.kr, postech.ac.kr
Valid 2026-06-12 00:00:00 → 2026-12-27 23:59:59

Tech Stack

Wappalyzer fingerprinting pending

HTTP-body analysis identifies web frameworks, CMS platforms, analytics, JS libraries and server-side languages from this host.

Origin / IP-Leak

USP

When a hostname is served behind a CDN (e.g. Cloudflare), the origin server can sometimes be identified by matching its TLS cert against the protected hostname. Findings shown here are heuristic candidates, not guarantees.

No origin-leak candidates for this IP

When this IP serves a TLS cert for a domain that fronts behind a CDN, that domain surfaces here as an origin-leak candidate with a confidence score.

Hosted Domains

1 domain resolve (A-record) to this IP.

Multi-Vantage Check

Reachability accrued passively from real user-triggered checks across our 65+ probe nodes. Run a live check to add fresh data.

No accumulated reachability data yet

Reachability accrues from real user-triggered checks. Trigger a Ping or HTTP check from our 65+ probe nodes to contribute the first data point.

Web Pages

Port Page title Status Flags
443 Welcome to Saunguk Kim Lab. (Structural Bioinformatics Lab.) - POSTECH 200
80 302 Found 302

Threat Intelligence

No threat-intel matches

This IP doesn't appear in any of the feeds we mirror (Tor exits, FireHOL Level 1-3, Spamhaus DROP/EDROP, URLhaus, OpenPhish). Absence here doesn't prove the IP is clean — it just means none of our public-feed sources flag it.

Co-Hosted Domains

Domains this host references in its HTML AND whose DNS A/AAAA record resolves back to this IP — i.e. actually hosted here.

sbi.postech.ac.kr DNS-confirmed

External References

Domains the body links to whose DNS does NOT resolve to this IP — usually CDN assets, embeds, or third-party services. Boilerplate (Google Fonts, jsDelivr, w3.org…) is already filtered.

www.ibric.org href · ×18
news.search.naver.com href · ×14
www.ploscompbiol.org href · ×8
www.nature.com href · ×8
academic.oup.com href · ×7
m.dongascience.com href · ×2
www.thelancet.com href · ×2
www.aitimes.kr href · ×1
www.sciencedirect.com href · ×1
n.news.naver.com href · ×1
www.veritas-a.com href · ×1
www.news1.kr href · ×1
mobile.newsis.com href · ×1
www.etnews.com href · ×1
bric.postech.ac.kr href · ×1
m.kmib.co.kr href · ×1
biz.chosun.com href · ×1
www.hkn24.com href · ×1
www.yonhapnews.co.kr href · ×1
elifesciences.org href · ×1
www.hankyung.com href · ×1
dx.plos.org href · ×1
www.notion.so href · ×1
www.postech.ac.kr href · ×1
m.etnews.com href · ×1
www.science.org href · ×1
www.yna.co.kr href · ×1

History

First observed
2026-05-26 20:48
Last observed
2026-07-27 16:32
Scan observations
6

The full change-log (ASN moves, cert rotations, port-state diffs) accumulates as our archives grow.