51.161.65.59📋 Copy

# IP Intelligence Briefing: 51.161.65.59

Classification: Moderate Risk / Cloud Infrastructure

Date: 2026-06-26

Analysis Type: Threat Intelligence Assessment

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## Executive Summary

IP 51.161.65.59 operates as cloud-hosted infrastructure under OVH's customer network OVH-CUST-281059690 in Montreal, Canada. The IP resolves to the ahrefs.net domain (proxy-ca011-san59.ahrefs.net) and exhibits moderate risk characteristics consistent with commercial cloud hosting. No active malicious indicators detected; however, the subnet demonstrates elevated abuse density requiring contextual awareness.

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## Network Profile

• IP Address: 51.161.65.59/32
• ASN: 16276 (OVH SAS)
• Organization: Dmytro, Ahrefs Pte Ltd
• Network Block: 51.161.65.0/24
• Infrastructure Type: CloudCompute (OVH)
• Service Classification: Hosting enabled, Firewalled/No Services
• Geolocation: Canada, Quebec, Montreal (3000km accuracy radius)

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## Risk Assessment

Threat Indicators:

• No known attacker status
• No Tor exit node activity
• No spam source classification
• Zero blacklist entries
• No known campaign associations

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## Subnet Analysis: 51.161.65.0/24

• Abuse Density: 0.5547 (High)
• Classification: High Abuse
• Total Subnet Siblings: 256
• Active Siblings: 218
• Threat Siblings: 142
• Inherited Risk: 22

The subnet exhibits elevated abuse density with 55% of active IPs flagged for potential misuse. This contextual factor should inform monitoring thresholds for traffic from this subnet.

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## DNS Resolution

• PTR Hostname: proxy-ca011-san59.ahrefs.net
• Resolved Domain: ahrefs.net
• Forward Resolution: Confirmed
• Email Authentication: SPF/DMARC not configured
• CAA Records: Present (2 issuers)

DNS infrastructure indicates legitimate cloud hosting for SEO analytics platform Ahrefs, consistent with organizational ownership.

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## Observational History

Twenty-one signal observations recorded as of 2026-06-26. Key temporal patterns:

• Geolocation: Consistent Canada classification
• Abuse Density: Stable at 0.5547
• DNS Resolution: Stable proxy hostname
• Operator Classification: Minimal threat posture maintained
• Threat Persistence: 0 days (no persistent malicious activity)

No escalation or de-escalation of risk posture observed over observation window.

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## Control Plane Analysis

• BGP Prefix: 51.161.0.0/17
• Route Stability: False
• DNSSEC Validation: Valid
• DNSBL Listings: 1 of 8 total lists
• IRR Consistency: Not evaluated
• Route Changes (30d): 0
• Multi-AS Origin: False

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## Neighborhood Risk Distribution

All 100 sampled neighbors in the /24 subnet classified as medium risk, with no high-risk outliers detected in this sample.

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## Recommended Actions

No immediate blocking required. The IP demonstrates characteristics consistent with legitimate cloud hosting infrastructure. However, SOC teams should:

1. Monitor traffic patterns from subnet 51.161.65.0/24 given elevated abuse density (0.5547)

2. Correlate with ahrefs.net domain activity for legitimate service identification

3. Apply standard cloud security policies rather than IP-specific blocking

4. Review DNS authentication (SPF/DMARC) for outbound communications from this infrastructure

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## Conclusion

IP 51.161.65.59 represents legitimate cloud hosting infrastructure under OVH for Ahrefs services. While the parent subnet shows elevated abuse density, this single IP lacks direct malicious indicators. Recommended approach: whitelist for ahrefs.net correlation while maintaining monitoring posture for subnet-level traffic anomalies.

Final Assessment: Moderate Risk - Monitor Contextually

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