51.161.37.118📋 Copy

# INTELLIGENCE BRIEFING: 51.161.37.118/32

Classification: Moderate Risk — Cloud Infrastructure in High-Abuse Subnet

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## EXECUTIVE SUMMARY

IP 51.161.37.118 is a cloud compute resource hosted on OVH infrastructure (ASN 16276) with a risk score of 40. The IP resolves to the legitimate domain ahrefs.net but is located within a high-abuse subnet (51.161.37.0/24) showing 74.22% abuse density. Geolocation data indicates significant validation issues with RTT anomalies suggesting potential spoofing.

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## OWNERSHIP & NETWORK ATTRIBUTES

• ASN: 16276 (OVH)
• Organization: Dmytro, Ahrefs Pte Ltd
• Network: OVH-CUST-281059684 (51.161.37.0/24)
• Infrastructure Type: Cloud Compute / Hosting
• DNS: proxy-ca005-san118.ahrefs.net
• Services: None detected (firewalled/no services)

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## GEOLOCATION VALIDATION

⚠️ Data Quality Alert: Geolocation reporting Singapore (CA) with 3000km accuracy radius is inconsistent with network measurements.

• Claimed Position: 43.6319°N, -79.3716°W (Toronto, Canada region)
• Measured RTT: 25–32ms
• Minimum Possible RTT: 121.6ms for reported distance (6082km)
• Violation: Measured RTT < minimum possible for claimed distance
• Conclusion: Geolocation data is implausible and should not be relied upon

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## THREAT INTELLIGENCE

• Risk Score: 40 (Moderate)
• Abuse Confidence: Not applicable
• Known Campaigns: None detected
• Tor Exit Node: No
• Known Attacker: No
• Spam Source: No
• Blacklist Count: 0
• Threat Feeds: None detected
• DNSBL Listed: 1 of 8 lists

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## SUBNET CONTEXT (51.161.37.0/24)

• Abuse Density: 0.7422 (High)
• Total Siblings: 256
• Active Siblings: 198
• Threat Siblings: 190
• Inherited Risk: 29
• Classification: HIGH ABUSE

The subnet shows elevated abuse activity with 95% of active IPs flagged as threat-related.

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## OBSERVATION HISTORY

• Total Observations: 19
• Recent Activity: 2026-06-15 (2 observations)
• Threat Persistence: Single observation period
• Ownership Changes: 0
• DNS Signals: ahrefs.net domain consistently observed
• Pattern: Stable infrastructure with persistent classification

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## RECOMMENDED ACTIONS

IMMEDIATE: Block Traffic

```

iptables -A INPUT -s 51.161.37.118 -j DROP

```

Platform-Specific Rules

• nftables: `nft add rule inet filter input ip saddr 51.161.37.118 drop`
• nginx: `deny 51.161.37.118;`
• pfSense: `51.161.37.118/32`
• Cloudflare WAF: Block with expression `ip.src eq 51.161.37.118`
• AWS WAF: Block address `51.161.37.118/32`

SUBNET-WIDE CONSIDERATION

Consider evaluating broader subnet 51.161.37.0/24 for monitoring or blocking given 74% abuse density.

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## ANALYST NOTES

• IP is legitimately associated with Ahrefs (SEO analytics company)
• High neighborhood abuse density suggests shared hosting infrastructure
• No active threat indicators detected
• Blocking recommended due to subnet-level risk and geolocation anomalies
• Monitor for similar IPs in 51.161.37.0/24 range

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Generated: Current

Data Source: IPDebrief Intelligence Platform

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