51.161.37.123📋 Copy

# IP Intelligence Briefing: 51.161.37.123

Classification: Moderate Risk | Provider: OVH Hosting | Location: Montreal, QC, Canada

## Executive Summary

IP 51.161.37.123 is a cloud infrastructure address assigned to OVH (ASN 16276) with a risk score of 40. The IP resolves to hostnames associated with Ahrefs (proxy-ca005-san123.ahrefs.net) but operates within a high-abuse subnet (51.161.37.0/24) exhibiting 76.95% abuse density. No active services or open ports were detected.

## Technical Profile

• Network Classification: OVH-CUST-281059684 (51.161.37.0/24)
• Infrastructure Type: CloudCompute / Hosting
• Geolocation: Montreal, Quebec, Canada
• DNS: proxy-ca005-san123.ahrefs.net (ahrefs.net)
• Services: None detected (firewalled/no services)
• Reputation Indicators: 1 DNSBL listing; minimal operator score (0.2174)
• Threat Indicators: No known campaigns, not a Tor exit, not a known spam source

## Neighborhood Analysis

The /24 subnet demonstrates elevated threat prevalence:

• Total Siblings: 256
• Active Siblings: 214
• Threat Siblings: 197
• Risk Distribution: 99 medium risk, 1 low risk, 0 high risk
• Consistent Pattern: Neighboring IPs show uniform risk scoring (40) with authority scores of 50

## Historical Observation

Signal history indicates persistent presence with 25 observations recorded from June 2021 through June 2026. The subnet abuse classification (high_abuse, 0.7695 density) has been stable. No significant threat escalation observed over the observation period.

## Recommended Actions

Block at perimeter: Implement firewall rules to deny traffic from this IP.

Platform-specific rules:

• iptables: `iptables -A INPUT -s 51.161.37.123 -j DROP`
• nftables: `nft add rule inet filter input ip saddr 51.161.37.123 drop`
• nginx: `deny 51.161.37.123;`
• Cloudflare WAF: Block IP 51.161.37.123 with risk score 40 filter
• AWS WAF: Add 51.161.37.123/32 to blocklist

## Contextual Notes

While the IP resolves to legitimate Ahrefs infrastructure (SEO analytics platform), the high-abuse subnet density suggests potential for credential stuffing, API abuse, or lateral movement from compromised accounts. The lack of active services indicates this may be a static proxy or backend node. Monitor for correlation with other Ahrefs-subnet IPs showing similar threat patterns.

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