IPDebrief

51.161.37.54

IP Intelligence Dossier
Your IP: 216.73.216.123
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🤖 Witness AIThis summary was generated by AI and may contain inaccuracies. Verify critical details independently.

# IPDEBRIEF INTELLIGENCE BRIEFING

Target: 51.161.37.54/32

Classification: Moderate Risk

Date: 2026-06-15

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## EXECUTIVE SUMMARY

IP 51.161.37.54 is a Canadian-hosted OVH cloud compute infrastructure address with a moderate risk profile (score: 40). The IP is associated with the ahrefs.net domain and operates within a high-abuse density subnet (51.161.37.0/24). While no active threat indicators or known campaigns are currently associated, the subnet context suggests elevated abuse potential requiring defensive posture awareness.

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## OWNERSHIP & INFRASTRUCTURE

AttributeValue
ASN16276 (OVH)
OrganizationDmytro, Ahrefs Pte Ltd
NetworkOVH-CUST-281059684
CIDR Block51.161.37.0/24
RegistrationARIN
GeolocationMontreal, Quebec, Canada
Infrastructure TypeCloud Compute / Hosting Provider

DNS Analysis:

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## THREAT INDICATORS

IndicatorStatus
Known AttackerFalse
Spam SourceFalse
Tor Exit NodeFalse
ProxyFalse
Active Threat IndicatorsNone
Blacklist Count0
DNSBL Listed1 of 8 lists
Known CampaignsNone
Threat PersistenceNone (0 days)

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## NEIGHBORHOOD ANALYSIS (51.161.37.0/24)

MetricValue
Subnet Abuse Density0.7422 (HIGH)
ClassificationHigh Abuse
Inherited Risk29
Total Siblings256
Active Siblings198
Threat Siblings190 (74%)
Risk DistributionHigh: 0, Medium: 99, Low: 1

Assessment: The /24 subnet exhibits significant abuse density. Of 256 sibling addresses, 190 are classified as threats (74% threat rate). This contextual risk should factor into decision-making despite the individual IP's moderate standalone score.

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## OBSERVATION HISTORY

- Subnet abuse classification (high_abuse): 2026-06-15

- Operator score (Minimal): 0.2174

- DNS records for ahrefs.net: 2026-06-09

- No banner/campaign matches observed

Temporal Trend: No evidence of persistent malicious behavior. Ownership stable with zero changes.

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## RELATIONSHIP GRAPH

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## RECOMMENDED ACTIONS

Immediate Defense (Firewall Rules)

PlatformRule
iptables`iptables -A INPUT -s 51.161.37.54 -j DROP`
nftables`nft add rule inet filter input ip saddr 51.161.37.54 drop`
nginx`deny 51.161.37.54;`
pfSense`51.161.37.54/32`
Cloudflare WAFBlock IP with expression `ip.src eq 51.161.37.54`
AWS WAFAdd `51.161.37.54/32` to IP set with description "IPDebrief risk 40"

Strategic Considerations

1. Subnet Context: Consider evaluating the entire /24 subnet (51.161.37.0/24) due to 74% threat density among siblings.

2. False Positive Risk: Low standalone threat indicators suggest defensive measures should be weighed against operational impact.

3. Monitoring: Continue monitoring for changes in DNSBL listings or emergence of threat indicators.

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Analyst Notes: This IP presents a moderate risk profile within a high-abuse neighborhood. The ahrefs.net association indicates legitimate SEO/marketing infrastructure usage, but the subnet context warrants defensive blocking. Balance operational requirements against the elevated neighborhood risk environment.

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

🌍 Geolocation

Country🇨🇦 Canada
RegionQC
CityMontreal
Timezone—
Latitude43.63
Longitude-79.37

🏢 Ownership & Registration

OrganizationDmytro, Ahrefs Pte Ltd
ASNAS16276
Network NameOVH-CUST-281059684
CIDR Block51.161.37.0/24
RIRARIN
CountrySingapore
Abuse Contact—

🌐 DNS Intelligence

PTRproxy-ca005-san54.ahrefs.net
Forward ConfirmedNo — PTR hostname does not resolve back to this IP (weak signal)
Forward Hostnamesproxy-ca005-san54.ahrefs.net

🔐 DNS Hygiene

Hygiene Score40% (Fair)
SPFNot configured
DMARCNot configured
FCrDNSNot verified
DNSSECValid
CAAPresent

☁️ Network Classification

InfrastructureInfrastructure / Datacenter
Service PurposeFirewalled / No Services
Network TierHosting — Infrastructure provider without advanced routing
CloudHosting

🔌 Services & Open Ports

PortServiceProtocolBanner
No open ports detected
Closed Ports22, 25, 80, 443, 3389, 8080, 8443 (0 open / 7 scanned)
Server—
HTTP Title—

🔐 TLS Certificate

🔒
No certificate
Issued by —
N/A
SANsNone
Valid From—
Valid Until—

🎯 Confidence Breakdown

Per-dimension confidence scores based on source diversity and data freshness

DimensionScoreSourcesObservations
threat
31%
24
routing
13%
11
services
15%
22
ownership
19%
22
reputation
31%
13
geolocation
33%
23
Overall24%1015
Coverage: 6/6 dimensions · Data sufficiency: sufficient
Data CoherenceMostly Consistent (80%) — 1 contradiction(s)
AttributionLow (35%)
OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid
⚠ Claimed geolocation contradicts RTT physics measurement

📅 Observation Timeline 🔄 Live

First Seen2026-05-21 21:00:50 UTC
Last Seen2026-06-28 16:08:54 UTC
Profile Built2026-06-29 04:14:37 UTC
Data FreshnessLive
Signal Types21
Total Observations23
🔍 21 signal types · 23 observations collected
This report is generated from 21+ independent intelligence signals including ownership records, DNS analysis, BGP routing, TLS certificates, port scanning, threat feeds, behavioral fingerprinting, and more.
Full dossier details are available via our API.
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ℹ️ About This Report

All data shown is publicly available network metadata — IP addresses do not reliably identify individuals. Assessments are probabilistic and should not be used as sole basis for access control decisions. To report an issue or request data review, contact admin@ipdebrief.com.