51.161.65.197📋 Copy

# IP INTELLIGENCE BRIEFING: 51.161.65.197/32

## Executive Summary

IP address 51.161.65.197 is a Canadian OVH Cloud Hosting resource with a moderate risk score of 40. The IP is associated with Ahrefs Pte Ltd and resolves to the ahrefs.net domain. While no direct threat indicators were identified, the subnet demonstrates elevated abuse activity (71% abuse density), warranting monitoring.

## Network Ownership and Geolocation

• Organization: Dmytro, Ahrefs Pte Ltd
• ASN: 16276 (OVH)
• Network: 51.161.65.0/24 (OVH-CUST-281059690)
• Location: Montreal, QC, Canada (3000km accuracy radius)
• Network Classification: CloudCompute / Hosting
• Infrastructure Type: Cloud Infrastructure (not CDN, VPN, or proxy)

## DNS and Service Analysis

• PTR Hostname: proxy-ca011-san197.ahrefs.net
• Domain: ahrefs.net
• Open Ports: None detected
• TLS Certificate: Not present
• HTTP Services: Not detected
• DNSSEC: Valid
• CAA Records: Present
• Forward Resolution: Confirmed to a single hostname

## Threat Indicators

• Risk Score: 40 (Moderate Risk)
• Blacklist Count: 0
• Known Attacker: False
• Spam Source: False
• Tor Exit Node: False
• Known Campaigns: None identified
• Abuse Confidence Score: Not available
• Threat Persistence: Single observation (not persistently malicious)

## Control Plane Analysis

• Operator Score: 0.2174 (Minimal)
• BGP Prefix: 51.161.0.0/17
• Route Stability: Unstable
• DNSBL Status: Listed on 1 of 8 total lists
• RPKI State: Not available
• IRR Consistency: Not available

## Subnet Neighborhood Assessment

• Subnet: 51.161.65.0/24
• Abuse Density: 0.7109 (High)
• Classification: High Abuse
• Total Sibling IPs: 256
• Active Sibling IPs: 209
• Threat Sibling IPs: 182
• Inherited Risk Score: 28
• Risk Distribution: 99 medium-risk, 1 low-risk neighbors

## Historical Observations

Analysis revealed 20 historical observations through 15 June 2026. Key signals include:

• Subnet abuse density classification (high_abuse)
• Certificate enumeration (0 certificates)
• Operator score assessment (minimal)
• Network profile scoring (6 dimensions covered, overall confidence 0.23)
• No persistent malicious activity detected
• No correlated IPs or banner matches identified

## Relationship Graph

38 relationships identified, primarily Same Network entries linking to OVH-CUST-281059690 network blocks. No additional organizational, hostname, or certificate relationships beyond the network associations.

## Recommended Security Actions

Based on the risk profile, the following firewall rules are recommended for deployment:

iptables: `iptables -A INPUT -s 51.161.65.197 -j DROP`

nftables: `nft add rule inet filter input ip saddr 51.161.65.197 drop`

nginx: `deny 51.161.65.197;`

pfSense: `51.161.65.197/32`

Cloudflare WAF: Block IP with expression `ip.src eq 51.161.65.197`

AWS WAF: Add 51.161.65.197/32 to block list

## Analyst Notes

The IP is hosted under Ahrefs, a legitimate SEO tools provider, but the subnet shows high abuse density typical of shared cloud hosting environments. The lack of open ports and no active threat indicators suggests this may be a dormant or properly configured resource. However, the high-abuse subnet classification and DNSBL listing on 1 of 8 lists indicate potential for abuse by other entities in the same infrastructure.

Recommendation: Monitor for lateral activity from related subnet IPs (182 threat siblings identified). Implement blocking rules if traffic patterns indicate abuse. Consider whitelist exception if this IP is known to be used for legitimate Ahrefs services.

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*Intel generated from IPDebrief analysis. All data sourced from IPDebrief intelligence platform.*

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