51.161.65.55📋 Copy

# IP INTELLIGENCE BRIEFING: 51.161.65.55/32

Classification: Moderate Risk - Cloud Compute Infrastructure

Report Generated: [Current Date]

Risk Score: 40/100

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## EXECUTIVE SUMMARY

IP address 51.161.65.55 is a cloud compute resource hosted on OVH infrastructure (ASN 16276, Customer 281059690) with moderate risk indicators. The IP resolves to aresolves to the ahrefs.net domain proxy infrastructure, operating in Singapore. While individual risk signals are minimal, the IP operates within a high-abuse density subnet (0.6094 abuse density) with 156 threat siblings in the /24 block, warranting defensive posture considerations.

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## INFRASTRUCTURE PROFILE

Ownership & Registration:

• Organization: Dmytro, Ahrefs Pte Ltd
• Provider: OVH SAS (Customer: OVH-CUST-281059690)
• ASN: 16276
• CIDR Block: 51.161.65.0/24
• RIR: ARIN

Geolocation:

• Reported Location: Singapore (CA)
• Coordinate Accuracy: 3,000 km
• Validation Status: GeoPlausible: FALSE
• RTT Anomaly: 27ms observed vs 121.6ms minimum required for 6,082 km distance (violation detected)

Network Role:

• Infrastructure Type: Cloud Compute
• Hosting: YES
• CDN: NO
• Proxy/Tor: NO
• Open Ports: NONE
• Service Status: Firewalled / No Services

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## THREAT INDICATORS

Current Risk Assessment:

• Risk Score: 40 (Moderate)
• Abuse Confidence Score: Not Available
• Blacklist Count: 0
• Known Attacker: NO
• Spam Source: NO
• Tor Exit Node: NO

DNSBL Status:

• Listed: YES (1 of 8 total DNSBL checks)
• Severity: HIGH
• Total DNSBL Lists: 8

Geolocation Validation:

• Violation: RTT 27.0ms < minimum possible 121.6ms for 6,082 km
• Probe Count: 5
• Avg RTT: 29.8ms

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## NETWORK NEIGHBORHOOD ANALYSIS

Subnet: 51.161.65.0/24

• Total Siblings: 256
• Active Siblings: 207
• Threat Siblings: 156
• Abuse Density: 0.6094 (HIGH_ABUSE classification)
• Inherited Risk: 24

Neighbor Risk Distribution (100 sampled):

• High Risk: 0
• Medium Risk: 100
• Low Risk: 0

Key Finding: While no single neighbor shows high-risk scores, the subnet exhibits elevated abuse density with 61% of IPs flagged for threat activity. This contextualizes the moderate risk score for 51.161.65.55.

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## OBSERVATION HISTORY

Temporal Analysis (Last 20 Observations):

1. 2026-06-28 14:17: Operator score 0.087 (Minimal), confidence 0.30

2. 2026-06-20 12:10: Operator score 0.2174 (Minimal), confidence 0.60

3. 2026-06-20 12:09: DNSBL listing detected, severity HIGH, total lists: 8

Trend Indicators:

• Threat persistence: 0 days
• Ownership changes: 0
• Persistent malicious activity: NO
• Signal consistency: Variable confidence levels (0.18–0.85)

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## RELATIONSHIP GRAPH

Total Relationships: 47

Primary Connections:

• Multiple "Same Network" relationships to OVH-CUST-281059690
• Infrastructure clustering indicates shared hosting environment

Associated Domains:

• Primary: ahrefs.net
• PTR Hostname: proxy-ca011-san55.ahrefs.net
• Forward Resolution: 1 hostname (forwardConfirmed: FALSE)

Email Authentication:

• SPF: NO
• DMARC: NO
• TXT Records: 0

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## SECURITY RECOMMENDATIONS

Action Status: No specific security recommendations generated (risk score < threshold)

Recommended Firewall Rules:

```bash

# iptables

iptables -A INPUT -s 51.161.65.55 -j DROP

# nftables

nft add rule inet filter input ip saddr 51.161.65.55 drop

# pfSense

51.161.65.55/32

# Cloudflare WAF

Action: Block

Filter: ip.src eq 51.161.65.55

# AWS WAF

Addresses: 51.161.65.55/32

Description: IPDebrief risk 40

```

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## INTELLIGENCE ANALYSIS

Risk Context: The moderate risk score (40) reflects the IP's operation within a high-abuse density subnet. The DNSBL listing indicates past reputation issues, though no active threat campaigns are currently associated with this IP.

Key Concerns:

1. Subnet Environment: 61% abuse density in /24 block suggests compromised peer infrastructure

2. Geolocation Inconsistency: RTT violations indicate potential routing manipulation or proxying

3. No Active Services: IP appears firewalled, limiting direct exploitation but increasing persistence risk

Mitigation Priority: MEDIUM

• Block at perimeter firewall if network policy permits
• Monitor for lateral movement within OVH subnet
• Investigate DNSBL listing origin

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END OF BRIEFING

*Data Source: IPDebrief Intelligence Platform*

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