51.222.168.64📋 Copy

# IP INTELLIGENCE BRIEFING: 51.222.168.64/32

Classification: Moderate Risk / High-Abuse Neighborhood

Report Date: 2026-06-16

Analysis Source: IPDebrief Threat Intelligence

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## EXECUTIVE SUMMARY

IP 51.222.168.64 is a cloud-hosted infrastructure address operating under OVH's customer network OVH-CUST-281059697. The IP exhibits moderate risk (score: 50) but resides within a subnet classified as high_abuse with an abuse density of 0.832. The IP is associated with the ahrefs.net domain but shows geolocation inconsistencies and lacks active service signatures.

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## NETWORK OWNERSHIP & INFRASTRUCTURE

Provider: OVH (ASN 16276)

Organization: Dmytro, Ahrefs Pte Ltd

CIDR Block: 51.222.168.0/24

Infrastructure Type: CloudCompute (Cloud: Yes, Hosting: Yes)

Network Classification: Firewalled / No Services

Control Plane Indicators:

• Origin ASN: 16276
• BGP Prefix: 51.222.0.0/16
• Route Stability: False (isRouteStable flag not set)
• Route Changes (30d): 0
• RPKI State: Not evaluated
• DNSSEC Valid: True
• DNSBL Listed: 2 of 8 total lists

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## GEOLOCATION ANALYSIS

Reported Location: Singapore (City), QC (Region), CA (Country Code)

GeoValidation Status: INVALID

Distance from Probe Origin: 5,597.9 km

RTT Violation: Measured 29.0ms vs minimum possible 112.0ms for 5,598km distance

GeoPlausible: False

Assessment: Significant geolocation discrepancy detected. The IP's reported Singapore location is inconsistent with RTT measurements, suggesting either misconfigured geolocation data or spoofed origin information.

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## THREAT INTELLIGENCE

Risk Score: 50 (Moderate)

Threat Indicators: None detected

Known Campaigns: None

Blacklist Count: 0

DNSBL Listed: 2 of 8 total lists

Threat Flags:

• Tor Exit Node: No
• Known Attacker: No
• Spam Source: No
• Proxy: No
• VPN: No

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## DNS & HOSTNAME ASSOCIATIONS

Primary PTR Hostname: proxy-ca018-san64.ahrefs.net

Associated Domain: ahrefs.net

Forward Resolution: Not confirmed

Email Authentication: SPF: False, DMARC: False

TXT Records: 0

Assessment: IP resolves to an Ahrefs proxy hostname but lacks proper email authentication records, indicating potential misconfiguration or unauthorized use of the domain.

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## NEIGHBORHOOD CONTEXT (51.222.168.0/24)

Subnet Classification: High Abuse

Abuse Density: 0.832 (elevated)

Total Subnet Siblings: 256

Active Siblings: 227

Threat Siblings: 213 (76% of active IPs)

Inherited Risk Score: 33

Assessment: The IP operates in a high-abuse subnet with a significant concentration of threat-adjacent addresses. This contextual factor elevates the risk profile despite the IP's moderate individual risk score.

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## OBSERVATION HISTORY

Total Observations: 19 signals over monitoring period

Recent Activity:

• 2026-06-16 05:04:43: Subnet abuse density 0.832 (high_abuse classification)
• 2026-06-16 04:59:55: Operator score 0.2174 (Minimal)
• 2026-06-12 00:34:16: Provider classification OVH, confirmed cloud infrastructure
• 2026-06-12 00:31:48: DNS association with ahrefs.net domain

Temporal Analysis: No persistent malicious behavior detected. Ownership changes: 0. Threat persistence days: 0.

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## RELATIONSHIP GRAPH

Total Relationships: 24 entities

Key Associations:

• Multiple Same Network references (OVH-CUST-281059697)
• DNS Association: proxy-ca018-san64.ahrefs.net (repeated 12 times)

Network Connections: Primarily same-network references and DNS hostname associations. No organization-to-organization relationships detected.

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## SERVICE & PORT SCAN DATA

Open Ports: None detected

TLS Certificate: Not available

HTTP Title: Not available

Server Banner: Not available

HTTP Version: Not available

Assessment: No active services detected, indicating the IP is either firewalled, unresponsive, or used for non-service purposes (e.g., NAT, scanning infrastructure).

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## ACTIONABLE RECOMMENDATIONS

Risk Score: 50 - Moderate Risk

Recommended Action: Block (context-dependent)

Firewall Rules:

• iptables: `iptables -A INPUT -s 51.222.168.64 -j DROP`
• nftables: `nft add rule inet filter input ip saddr 51.222.168.64 drop`
• nginx: `deny 51.222.168.64;`
• pfSense: `51.222.168.64/32`
• Cloudflare WAF: Block IP with expression `ip.src eq 51.222.168.64`
• AWS WAF: Add `51.222.168.64/32` to IP set with description "

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Cloudflare WAF: `{"description": "Block 51.222.168.64 — IPDebrief risk score 50", "action": "block", "filter": {"expression": "ip.src eq 51.222.168.64"}}`

AWS WAF: `{"Addresses": ["51.222.168.64/32"], "Description": "IPDebrief risk 50"}`

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## TECHNICAL OBSERVATIONS

Traceroute Analysis:

• Hop Count: 17
• First Hop RTT: 0.2ms
• Last Hop RTT: 27.2ms
• Timed Out Hops: 6 (35% path loss)

DNS Records:

• DNSSEC: Valid
• CAA Records: Present (1 issuer)
• Forward Resolution: Unconfirmed
• PTR Hostnames: proxy-ca018-san64.ahrefs.net

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## RISK ASSESSMENT MATRIX

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## CONTEXTUAL INTELLIGENCE

The subnet 51.222.168.0/24 demonstrates high abuse density with 213 out of 227 active sibling IPs flagged as threats. This suggests the subnet is being utilized for:

• Bulk hosting operations
• Potentially compromised customer infrastructure
• Legitimate services operating alongside malicious actors

The IP's association with the ahrefs.net domain (a legitimate SEO analytics service) creates a dual-use scenario where the IP may be:

• Legitimate business infrastructure with poor security posture
• Hijacked or misconfigured assets
• Legitimate proxy service with elevated risk profile

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## ANALYST NOTES

1. False Positive Consideration: The IP may represent legitimate Ahrefs infrastructure given the DNS association, but the high-abuse neighborhood context warrants caution.

2. Geolocation Discrepancy: The reported Singapore location conflicts with RTT measurements. This could indicate:

- Incorrect BGP announcements

- Cloud infrastructure with misleading geo-data

- Potential obfuscation attempts

3. Email Security: The absence of SPF and DMARC records for ahrefs.net on this IP suggests either:

- Legitimate service not yet configured for email

- Compromised or unauthorized use of the domain

- Misconfigured mail relay

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## DECISION MATRIX FOR SOC

Primary Recommendation: Block or rate-limit based on organizational policy for high-abuse neighborhoods. Monitor for lateral movement or related infrastructure compromise.

Secondary Recommendation: Investigate email authentication records and verify if this IP should be associated with the ahrefs.net domain.

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End of Briefing

*Generated by IPDebrief Threat Intelligence Platform*

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