18.239.183.121
18.239.183.121 is an IPv4 address operated by Amazon.com, Inc. (AS16509), geolocated to Boston, United States. Its reverse DNS name is server-18-239-183-121.bos50.r.cloudfront.net. As of October 31, 2026, IPDebrief rates it Low Risk (25/100); no anonymizing service was detected.
Analysis of IP address 18.239.183.121 identified the host as an Amazon CloudFront web server node operating under AS16509. Ownership records attributed the infrastructure to Amazon.com, Inc. within the 18.238.0.0/15 CIDR block. The address maintained a low-risk reputation score of 25 with zero blacklisting and no active threat indicators.
Geolocation data reported the node in Boston, US, yet physical RTT measurements indicated a distance of 7,625 km, violating minimum propagation constraints. The immediate subnet showed mixed usage with 33 active threat siblings, though this specific address recorded no specific malicious activity. DNS hygiene remained excellent with valid SPF and DMARC configurations. Consequently, the recommendation was to monitor the address for changes, with the severity classified as low pending resolution of the signal contradictions.
This summary was generated by AI and may contain inaccuracies. Verify critical details independently.
🏢 Ownership & Registration
| Organization | Amazon.com, Inc. |
| ASN | AS16509 |
| Network Name | AMAZON-CF |
| CIDR Block | 18.238.0.0/15 |
| RIR | ARIN |
| Country | United States |
| Abuse Contact | Available via RDAP |
🌐 DNS Intelligence
| PTR | server-18-239-183-121.bos50.r.cloudfront.net |
| Forward Confirmed | Yes — FCrDNS verified |
| Forward Hostnames | server-18-239-183-121.bos50.r.cloudfront.net |
🔐 DNS Hygiene
| Hygiene Score | 80% (Excellent) |
| SPF | Present |
| DMARC | Present |
| FCrDNS | Verified |
| DNSSEC | Not signed |
| CAA | Present |
☁️ Network Classification
| Infrastructure | Unknown |
| Service Purpose | Web Server |
| Network Tier | Tier 2 — Moderate operator sophistication with routing hygiene |
🔌 Services & Open Ports
| Port | Service | Protocol | Banner |
|---|---|---|---|
| 80 | http | tcp | — |
| 443 | https | tcp | — |
| Closed Ports | 22, 25, 3389, 8080, 8443 (2 open / 7 scanned) | ||
| Server | Web server detected |
| HTTP Title | — |
🔐 TLS Certificate
| SANs | None |
| Valid From | — |
| Valid Until | — |
🛡️ Public Network Snapshot
| Origin ASN | AS16509 |
| Network Prefix | 18.239.176.0/21 |
| Route mapping | Found |
| RPKI Status | Valid |
🎯 Confidence Breakdown
Per-dimension confidence scores based on source diversity and data freshness
| Dimension | Score | Sources | Observations |
|---|---|---|---|
| threat | 37% | 2 | 6 |
| routing | 38% | 4 | 5 |
| services | 38% | 2 | 5 |
| ownership | 30% | 3 | 4 |
| reputation | 32% | 1 | 5 |
| geolocation | 27% | 2 | 4 |
| Overall | 34% | 14 | 29 |
| Data Coherence | Mostly Consistent (80%) — 1 contradiction(s) |
| Attribution | High (85%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-10-02 22:22:44 UTC |
| Last Seen | 2026-10-31 20:34:57 UTC |
| Profile Built | 2026-10-31 20:42:21 UTC |
| Data Freshness | Live |
| Signal Types | 31 |
| Total Observations | 46 |
Full dossier details are available via our API.
❓ Frequently Asked Questions About 18.239.183.121
Who owns the IP address 18.239.183.121?
18.239.183.121 is registered to Amazon.com, Inc.. The address falls within the 18.238.0.0/15 network block. Registration is held at ARIN.
Where is 18.239.183.121 located?
Geolocation data places 18.239.183.121 in Boston, US-MA, United States. IP geolocation is approximate and indicates the network's registered or routed location rather than a precise physical address.
Is 18.239.183.121 malicious or safe?
18.239.183.121 currently carries a low risk assessment, meaning no significant threat indicators have been observed. This assessment is generated from continuously collected signals and can change over time.
What is the hostname for 18.239.183.121?
The reverse DNS (PTR) record for 18.239.183.121 is server-18-239-183-121.bos50.r.cloudfront.net. This hostname is forward-confirmed, meaning it resolves back to the same address.
What ports are open on 18.239.183.121?
Responsive ports observed on 18.239.183.121 include 80, 443. Port visibility reflects the most recent scan and may change as the host's configuration or firewall rules change.