54.39.0.135📋 Copy

# INTELLIGENCE BRIEFING: 54.39.0.135/32

Classification: Moderate Risk - Cloud Infrastructure IP

Date: 2026-06-18

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## EXECUTIVE SUMMARY

IP 54.39.0.135 is a cloud-compute infrastructure address hosted on OVH infrastructure, associated with Ahrefs Pte Ltd. The IP presents a moderate risk score (40) primarily due to elevated neighborhood abuse density rather than direct malicious indicators. No open services detected; traffic is likely firewalled.

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## OWNERSHIP & INFRASTRUCTURE

• ASN: 16276 (OVH)
• Organization: Dmytro, Ahrefs Pte Ltd
• CIDR Block: 54.39.0.0/24
• Infrastructure Type: CloudCompute / Hosting
• DNS Resolution: proxy-ca004-san135.ahrefs.net (Ahrefs network)
• Services: No open ports detected (Firewalled / No Services)
• Location: Beauharnois, QC, Canada (CA)
• Note: Geolocation validation shows RTT discrepancy (26ms observed vs. 112.6ms minimum possible for distance)

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## THREAT ASSESSMENT

Risk Score: 40 (Moderate Risk)

Risk Drivers:

• Subnet-level abuse density: 0.6953 (High)
• Inherited risk from neighborhood: 27
• DNSBL listings: 1 of 8 total lists
• Operator score: 0.2174 (Minimal)

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## NEIGHBORHOOD ANALYSIS

Subnet: 54.39.0.0/24

Context: The /24 subnet shows significant abuse concentration. 178 of 220 active sibling IPs are flagged as threat IPs. This contextual risk elevates the target IP's risk profile despite lack of direct malicious indicators.

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## OBSERVATION HISTORY

Total Observations: 23 signals

Recent Activity:

• 2026-06-18T13:48:32 UTC: Subnet abuse classification confirmed (abuse_density: 0.6953)
• 2026-06-18T13:45:54 UTC: Control plane operator score: 0.2174 (Minimal)
• 2026-06-14T05:53:49 UTC: Geographic location signal: CA (confidence: 0.175)

Temporal Analysis: No evidence of persistently malicious behavior. Threat observation count: 1. Ownership stable with zero changes recorded.

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## RELATIONSHIP GRAPH

Connected Entities: 45 relationship indicators

• Primary Association: OVH-CUST-281059683 (Multiple network-level links)
• DNS Relationship: Ahrefs.net domain infrastructure
• Network Classification: Same Network relationships to OVH customer subnet

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## RECOMMENDED ACTIONS

Blocking Recommended: Yes (Probabilistic - combine with other signals)

Firewall Rules:

```bash

# iptables

iptables -A INPUT -s 54.39.0.135 -j DROP

# nftables

nft add rule inet filter input ip saddr 54.39.0.135 drop

# nginx

deny 54.39.0.135;

# pfSense

54.39.0.135/32

# Cloudflare WAF

ip.src eq 54.39.0.135 → Block

# AWS WAF

54.39.0.135/32 → Block

```

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## ANALYST NOTES

• Infrastructure Context: This is a headless cloud server with no exposed services. The risk profile is neighborhood-driven rather than IP-specific.
• Ahrefs Association: DNS resolution points to Ahrefs proxy infrastructure, suggesting legitimate use case. However, the high-abuse subnet context warrants monitoring.
• Mitigation Strategy: Consider subnet-level policies if the threat profile extends across the /24. Monitor for correlated malicious activity from sibling IPs.
• False Positive Risk: Moderate. The IP may be legitimately hosted infrastructure within a high-risk cloud block.

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END OF BRIEFING

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