51.161.37.211📋 Copy

## IP Intelligence Briefing: 51.161.37.211/32

Date: 2026-06-21

Classification: Moderate Risk

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Executive Summary

IP 51.161.37.211 is a cloud-hosted infrastructure endpoint associated with OVH (ASN 16276) under customer identifier OVH-CUST-281059684. The IP presents a moderate risk profile (score: 40) with concerning neighborhood abuse density (0.7734). No direct threat indicators were identified, but the subnet environment shows elevated threat activity.

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Ownership and Network Context

• Provider: OVH
• Organization: Dmytro, Ahrefs Pte Ltd
• CIDR Block: 51.161.37.0/24
• Infrastructure Type: Cloud Compute / Hosting
• RIR: ARIN

Geolocation Discrepancy: Multiple geolocation sources report conflicting data. Primary consensus indicates Canada (CA), with one source reporting Singapore. This inconsistency warrants monitoring.

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Threat Assessment

Threat Persistence: 0 days observed. The IP is not classified as persistently malicious.

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Neighborhood Analysis

The /24 subnet (51.161.37.0/24) exhibits high-risk characteristics:

• Abuse Density: 0.7734 (High Abuse Classification)
• Total Subnet Siblings: 256
• Active Siblings: 198
• Threat Siblings: 198
• Inherited Risk Score: 30

This subnet environment demonstrates significant abuse potential. The 77% abuse density suggests coordinated or opportunistic misuse patterns common to OVH hosting infrastructure.

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DNS and Service Profile

• PTR Hostname: proxy-ca005-san211.ahrefs.net
• Associated Domain: ahrefs.net
• Forward Resolution: Confirmed
• Open Ports: None detected
• TLS Certificate: None
• Email Authentication: SPF/DMARC not configured

Behavioral Note: The PTR hostname suggests proxy functionality but no active services are detected.

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Historical Observations (22 Total)

Recent signal history indicates:

• 2026-06-21: Geolocation reports from Montreal, QC (Canada) and Singapore (conflicting sources)
• 2026-06-16: High abuse density classification (0.7734) recorded for the subnet
• Operator Score: 0.2174 (Minimal)
• Route Stability: Unstable (route changes observed in 30-day window)

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Recommended Security Actions

Based on risk profile and neighborhood context:

Immediate Mitigation:

```bash

# iptables

iptables -A INPUT -s 51.161.37.211 -j DROP

# nftables

nft add rule inet filter input ip saddr 51.161.37.211 drop

# Cloudflare WAF

Block 51.161.37.211 — IPDebrief risk score 40

```

Contextual Considerations:

• Blocking is recommended due to moderate risk score (40) and high-abuse neighborhood
• Monitor for escalation; one threat observation recorded in history
• Consider blocking the entire /24 subnet if risk tolerance permits

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Intelligence Notes

1. The IP resolves to an ahrefs.net domain, suggesting legitimate web infrastructure potential

2. Conflicting geolocation data (Canada vs. Singapore) requires validation through additional telemetry

3. High neighborhood abuse density (0.7734) indicates this subnet is frequently abused

4. No email authentication records configured for the associated domain

Analyst Recommendation: Implement blocking rules with monitoring. Re-evaluate within 7 days based on traffic patterns and continued threat observations.

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*Intel produced by IPDebrief Intelligence Analysis Division*

This summary was generated by AI and may contain inaccuracies. Verify critical details independently.