51.161.37.2
# IP INTELLIGENCE BRIEFING: 51.161.37.2
Classification: Moderate Risk (40/100)
Date: Current Analysis
Intel Quality: High (21 historical observations, 47 relationship entities)
---
## EXECUTIVE SUMMARY
IP 51.161.37.2 is a cloud hosting infrastructure IP assigned to OVH (ASN 16276) under customer OVH-CUST-281059684. The address resolves to aresolves to proxy-ca005-san2.ahrefs.net within the ahrefs.net domain. The IP operates within a high-abuse subnet (51.161.37.0/24) with 76.56% abuse density and 196 active threat siblings out of 208 active addresses.
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## NETWORK ATTRIBUTES
| Attribute | Value |
|---|---|
| **ASN** | 16276 (OVH) |
| **Organization** | Dmytro, Ahrefs Pte Ltd / OVH-CUST-281059684 |
| **Geolocation** | Montreal, QC, CA (consensus: true) |
| **Infrastructure Type** | CloudCompute (Hosting) |
| **Classification** | High Abuse Subnet |
| **Network Role** | Firewalled / No Services Detected |
---
## THREAT ASSESSMENT
Risk Score: 40/100 (Moderate)
Positive Indicators:
- No known attacker indicators
- No Tor exit node activity
- No spam source designation
- No blacklist matches (blacklist count: 0)
- Not identified as proxy, VPN, or residential IP
Concern Indicators:
- Subnet abuse density: 0.7656 (high_abuse classification)
- Inherited risk from subnet: 30/100
- DNSBL listed on 1 of 8 total lists
- 196 threat siblings within same /24 subnet
- Geo validation discrepancy: 6,082 km distance with minimum RTT violation (26ms vs 121.6ms minimum)
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## RESOLUTION & DNS PROFILE
| Field | Value |
|---|---|
| **PTR Hostname** | proxy-ca005-san2.ahrefs.net |
| **Domain** | ahrefs.net |
| **Forward Resolution** | Confirmed |
| **Forward Hostnames** | proxy-ca005-san2.ahrefs.net |
| **Forward Resolution Count** | 1 |
Email Authentication: No SPF/DMARC records configured for ahrefs.net
---
## OBSERVATION HISTORY
Total Observations: 21 signals
Recent Timeline (June 2026):
- 2026-06-20 14:04:48 – Subnet classification: high_abuse, abuse_density: 0.7656, inherited_risk: 30
- 2026-06-20 14:02:32 – Infrastructure classification: CloudCompute, provider: OVH
- 2026-06-20 14:00:21 – Operator score: 0.2174 (Minimal), DNSSEC valid
Temporal Analysis:
- Ownership changes: 0
- Threat persistence days: 0
- Is persistently malicious: False
- Threat observation count: 1
---
## NEIGHBORHOOD ANALYSIS (51.161.37.0/24)
| Metric | Value |
|---|---|
| **Total Siblings** | 256 |
| **Active Siblings** | 208 |
| **Threat Siblings** | 196 |
| **Abuse Density** | 0.7656 |
| **Inherited Risk** | 30 |
| **Risk Distribution** | 99 medium, 1 low, 0 high |
Sample Neighbor Risk Scores:
- 51.161.37.0: Risk 40, Authority 50
- 51.161.37.1: Risk 40, Authority 50
- 51.161.37.3: Risk 40, Authority 50
- 51.161.37.4: Risk 40, Authority 50
---
## RELATIONSHIP GRAPH
Total Relationships: 47 entities
Primary Entity Types:
- Same Network: OVH-CUST-281059684 (42+ relationships)
---
## RECOMMENDED ACTIONS
Monitoring Priority: MEDIUM
Recommended Controls:
1. Network Monitoring: Enable enhanced logging for this subnet due to high abuse density (0.7656)
2. Traffic Analysis: Monitor for anomalous outbound connections from the ahrefs.net PTR hostname
3. Geolocation Verification: Flag for geo-validation discrepancy (6,082 km distance with RTT violation)
4. DNSBL Monitoring: Track blacklist status changes (currently listed on 1 of 8 lists)
5. Subnet Context: Apply subnet-level rules for 51.161.37.0/24 given 196 active threat siblings
No Immediate Block Required: IP not flagged as known attacker, Tor exit, or spam source. Monitor for behavioral anomalies given subnet context.
---
Report Generated: IPDebrief Intelligence Platform
Intel Confidence: High (multiple signal sources, historical persistence)
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-san2.ahrefs.net |
| Forward Confirmed | No — PTR hostname does not resolve back to this IP (weak signal) |
| Forward Hostnames | proxy-ca005-san2.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 | 15% | 2 | 2 |
| ownership | 19% | 2 | 2 |
| reputation | 31% | 1 | 3 |
| geolocation | 33% | 2 | 3 |
| Overall | 24% | 10 | 15 |
| Data Coherence | Mostly Consistent (80%) — 1 contradiction(s) |
| Attribution | Low (35%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-05-21 21:00:50 UTC |
| Last Seen | 2026-06-28 16:08:20 UTC |
| Profile Built | 2026-06-29 04:12:21 UTC |
| Data Freshness | Live |
| Signal Types | 22 |
| Total Observations | 24 |
Full dossier details are available via our API.