51.161.37.135📋 Copy

# IP Intelligence Briefing: 51.161.37.135

## Executive Summary

IP address 51.161.37.135 presents a moderate risk profile (Score: 40) operating within the OVH cloud infrastructure. While the IP itself shows no direct malicious activity, it resides in a subnet with elevated abuse density (0.7422) where 76% of active siblings exhibit threat indicators. The IP resolves to an Ahrefs domain but operates with firewalled services and no active open ports.

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## Ownership and Infrastructure

• ASN: 16276 (OVH)
• Organization: Dmytro, Ahrefs Pte Ltd
• Network Block: 51.161.37.0/24
• Infrastructure Type: CloudCompute (OVH hosting provider)
• Service Purpose: Firewalled / No Services detected

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## Geolocation Analysis

• Consensus Location: Singapore (country code: CA)
• Data Quality: GeoPlausible validation failed, indicating geolocation inconsistencies
• Geolocation Conflicts: Historical observations show conflicting data between country code "CA" and coordinates (56.13, -106.35), suggesting data source discrepancies that warrant monitoring

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## Threat Intelligence

Current Risk Profile

• Risk Score: 40 (Moderate Risk)
• Blacklist Status: Not on active threat feeds; 0 blacklist entries
• DNSBL: Listed on 1 of 8 total DNSBL lists
• Operator Score: 0.2174 (Minimal)
• Reputation Labels: No known attacker, not Tor exit node, not spam source

Network Context (51.161.37.0/24)

• Abuse Density: 0.7422 (High Abuse Classification)
• Subnet Statistics: 256 total IPs, 198 active, 190 threat siblings
• Inherited Risk: 29
• Risk Distribution: 0 high, 99 medium, 1 low

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## Historical Observations

• Total Signals: 18 observations
• Recent Activity: Last observation 2026-06-15
• Threat Persistence: 0 days (not persistently malicious)
• Key Historical Findings:

- DNSBL listings observed (1 of 8 lists)

- Geolocation inconsistencies across observation period

- Operator score maintained at minimal levels

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## Domain and DNS Intelligence

• PTR Hostname: proxy-ca005-san135.ahrefs.net
• Domain: ahrefs.net
• Forward Resolution: 1 confirmed hostname
• Email Authentication: SPF and DMARC records not detected
• Certificate Status: No TLS certificates observed

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## Recommended Actions

Immediate Recommendations

Based on the moderate risk profile and neighborhood context, the following controls are recommended:

Operational Considerations

• Blocking Rationale: Moderate risk score combined with high-abuse subnet context
• False Positive Risk: Low; IP shows no direct malicious indicators
• Monitoring Priority: Medium – neighborhood context suggests elevated threat proximity
• Reassessment Trigger: Monitor for DNSBL listing changes or service activation

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## Intelligence Assessment

The IP address 51.161.37.135 operates within a compromised subnet environment. While the IP itself demonstrates no active malicious behavior, the high abuse density (0.7422) and 76% threat sibling rate indicate systemic infrastructure abuse within the /24 block. The geolocation inconsistencies and DNSBL listings suggest potential reputation degradation or misuse patterns. SOC analysts should monitor this IP for service activation or behavioral changes while maintaining blocking controls in alignment with organizational security posture.

Classification: Moderate Risk – Contextual Threat (Infrastructure Abuse Zone)

Action Status: Block Recommended

Monitoring Priority: Medium

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