51.161.37.217
## IP INTELLIGENCE BRIEFING: 51.161.37.217/32
Classification: Cloud Hosting Infrastructure - Moderate Risk
Risk Score: 40/100
Ownership & Infrastructure
- ASN: 16276 (OVH)
- Organization: Dmytro, Ahrefs Pte Ltd
- CIDR Block: 51.161.37.0/24
- Infrastructure Type: CloudCompute
- PTR Hostname: proxy-ca005-san217.ahrefs.net
- Domain: ahrefs.net
Geolocation Assessment
- Reported Location: Singapore (geographic discrepancy noted)
- Country Code: CA (Canada)
- Accuracy Radius: 3000km
- Validation Status: GeoPlausible=false (inconsistent data sources)
Neighborhood Context (Subnet: 51.161.37.0/24)
- Abuse Density: 76.56% (HIGH)
- Classification: high_abuse
- Active Siblings: 208/256
- Threat-Sibling IPs: 196
- Subnet Risk Profile: Elevated risk environment with significant abuse activity
Threat Indicators
- Blacklist Status: 0/0 direct threat indicators
- DNSBL Listings: 1 of 8 total lists
- Tor/VPN/Proxy: Not flagged
- Known Campaigns: None correlated
- Campaign Likelihood: None
Observation History
- Total Observations: 21 signals
- Recent Activity: Signals observed 2026-06-28
- Infrastructure Classification: Cloud hosting confirmed
- DNS Resolution: Consistent ahrefs.net ownership
- Risk Trend: Stable with recent minimal risk signals
Recommended Security Actions
Based on risk score 40 and neighborhood abuse density:
Firewall Blocking Rules:
- `iptables -A INPUT -s 51.161.37.217 -j DROP`
- `nft add rule inet filter input ip saddr 51.161.37.217 drop`
- `nginx: deny 51.161.37.217;`
WAF Recommendations:
- Cloudflare WAF: Block IP with expression `ip.src eq 51.161.37.217`
- AWS WAF: Add to block list: `51.161.37.217/32`
Analyst Notes
This IP resides in a high-abuse OVH cloud subnet with 76% abuse density. While the target IP lacks direct malicious indicators, the neighborhood context suggests elevated risk. The PTR hostname indicates Ahrefs infrastructure, which may be legitimate SEO/analytics services. Recommend blocking at perimeter layers while maintaining investigation on inbound traffic patterns to distinguish legitimate vs. compromised use of this IP.
Priority: MEDIUM
Action: Block at firewall/WAF level; monitor for traffic anomalies
This summary was generated by AI and may contain inaccuracies. Verify critical details independently.
🏢 Ownership & Registration
| Organization | Dmytro, Ahrefs Pte Ltd |
| ASN | AS16276 |
| Network Name | OVH-CUST-281059684 |
| CIDR Block | 51.161.37.0/24 |
| RIR | ARIN |
| Country | Singapore |
| Abuse Contact | — |
🌐 DNS Intelligence
| PTR | proxy-ca005-san217.ahrefs.net |
| Forward Confirmed | No — PTR hostname does not resolve back to this IP (weak signal) |
| Forward Hostnames | proxy-ca005-san217.ahrefs.net |
🔐 DNS Hygiene
| Hygiene Score | 40% (Fair) |
| SPF | Not configured |
| DMARC | Not configured |
| FCrDNS | Not verified |
| DNSSEC | Valid |
| CAA | Present |
☁️ Network Classification
| Infrastructure | Infrastructure / Datacenter |
| Service Purpose | Firewalled / No Services |
| Network Tier | Hosting — Infrastructure provider without advanced routing |
🔌 Services & Open Ports
| Port | Service | Protocol | Banner |
|---|---|---|---|
| No open ports detected | |||
| Closed Ports | 22, 25, 80, 443, 3389, 8080, 8443 (0 open / 7 scanned) | ||
| Server | — |
| HTTP Title | — |
🔐 TLS Certificate
| SANs | None |
| Valid From | — |
| Valid Until | — |
🎯 Confidence Breakdown
Per-dimension confidence scores based on source diversity and data freshness
| Dimension | Score | Sources | Observations |
|---|---|---|---|
| threat | 31% | 2 | 4 |
| routing | 13% | 1 | 1 |
| services | 12% | 2 | 2 |
| ownership | 15% | 2 | 2 |
| reputation | 28% | 1 | 3 |
| geolocation | 25% | 2 | 2 |
| Overall | 21% | 10 | 14 |
| Data Coherence | Consistent (100%) |
| Attribution | Moderate (50%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-05-22 03:10:07 UTC |
| Last Seen | 2026-06-28 17:40:19 UTC |
| Profile Built | 2026-06-29 05:42:42 UTC |
| Data Freshness | Live |
| Signal Types | 19 |
| Total Observations | 21 |
Full dossier details are available via our API.