54.39.136.81
## IP Intelligence Briefing: 54.39.136.81
Classification: Moderate Risk | Risk Score: 40 | Last Updated: 2026-06-19
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Executive Summary
IP address 54.39.136.81 belongs to OVH hosting infrastructure (ASN 16276) and is associated with ahrefs.net domain infrastructure. The IP presents moderate risk with a score of 40/100. No active threat indicators were observed, but the subnet exhibits elevated abuse density (0.68) with 175 of 256 sibling IPs flagged as threat sources. Geographic validation anomalies detected.
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Network Ownership & Infrastructure
| Attribute | Value |
|---|---|
| **ASN** | 16276 |
| **Organization** | Dmytro, Ahrefs Pte Ltd |
| **Netname** | OVH-CUST-281059681 |
| **CIDR Block** | 54.39.136.0/24 |
| **Infrastructure Type** | CloudCompute |
| **Hosting Provider** | OVH |
| **Status** | Cloud/Hosting |
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Geolocation Analysis
| Field | Value | Status |
|---|---|---|
| **Country** | CA (Canada) | ⚠️ Flagged |
| **Region** | QC (Quebec) | ⚠️ Flagged |
| **City** | Beauharnois | ⚠️ Flagged |
| **RTT Violation** | 27ms observed vs 112.6ms minimum | ⚠️ Flagged |
*Note: Geographic data shows RTT distance discrepancy of 5,628.6km, indicating potential reporting inconsistencies or multi-hop routing.*
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DNS & Service Profile
| Component | Details | |
|---|---|---|
| **PTR Hostname** | proxy-ca002-san81.ahrefs.net | |
| **Reverse DNS** | proxy-ca002-san81.ahrefs.net | |
| **Forward Confirmed** | No | |
| **Services** | Firewalled / No Services Open | |
| **TLS Certificate** | None detected | |
| **Email Auth** | SPF: No | DMARC: No |
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Threat Intelligence
| Indicator | Status |
|---|---|
| **Tor Exit Node** | No |
| **Known Attacker** | No |
| **Spam Source** | No |
| **Blacklist Count** | 0 |
| **Campaign Matches** | 0 |
| **Threat Persistence** | 0 days |
| **Abuse Confidence** | Not available |
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Neighborhood Analysis (54.39.136.0/24)
| Metric | Value | ||
|---|---|---|---|
| **Subnet Classification** | High Abuse | ||
| **Abuse Density** | 0.6836 | ||
| **Total Siblings** | 256 | ||
| **Active Siblings** | 182 | ||
| **Threat Siblings** | 175 | ||
| **Risk Distribution** | High: 0 | Medium: 54 | Low: 46 |
*Note: Subnet shows significant concentration of compromised or flagged IPs. 68% abuse density warrants heightened scrutiny.*
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Control Plane & Routing
| Parameter | Value |
|---|---|
| **Origin ASN** | 16276 |
| **BGP Prefix** | 54.39.0.0/16 |
| **AS Path** | 57866 → 16276 |
| **Route Stability** | Stable (0 changes in 30d) |
| **DNSBL Listed** | 1 of 8 total lists |
| **Operator Score** | 0.4348 (Basic) |
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Historical Signals (Last 25 Observations)
Recent observations captured through 2026-06-19 show:
- ASN allocation age: 9,255 days (RIPE NCC)
- BGP communities: 1403:5001
- Operator scoring: Basic classification maintained
- Ownership stability: No changes recorded
- Threat observation count: 1
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Recommended Actions
| System | Action |
|---|---|
| **iptables** | `iptables -A INPUT -s 54.39.136.81 -j DROP` |
| **nftables** | `nft add rule inet filter input ip saddr 54.39.136.81 drop` |
| **nginx** | `deny 54.39.136.81;` |
| **pfSense** | Block 54.39.136.81/32 |
| **Cloudflare WAF** | Block with risk score 40 |
| **AWS WAF** | Add to blocked addresses list |
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Intelligence Assessment
This IP address operates within OVH cloud infrastructure and is associated with ahrefs.net reverse DNS records. While the IP itself shows no active threat indicators, the subnet (54.39.136.0/24) demonstrates concerning abuse patterns with 175 threat siblings. The moderate risk score (40) combined with high subnet abuse density suggests this infrastructure may be used for legitimate purposes but exists in a high-risk environment.
Recommendation: Monitor rather than block immediately. The lack of direct threat indicators and the presence of reverse DNS for a legitimate service provider (ahrefs.net) suggest legitimate use. However, implement traffic logging and monitor for anomalous behavior given the neighborhood risk profile.
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*Intel generated by IPDebrief. All data based on observed signals and network intelligence.*
This summary was generated by AI and may contain inaccuracies. Verify critical details independently.
🏢 Ownership & Registration
| Organization | Dmytro, Ahrefs Pte Ltd |
| ASN | AS16276 |
| Network Name | OVH-CUST-281059681 |
| CIDR Block | 54.39.136.0/24 |
| RIR | ARIN |
| Country | Singapore |
| Abuse Contact | — |
🌐 DNS Intelligence
| PTR | proxy-ca002-san81.ahrefs.net |
| Forward Confirmed | No — PTR hostname does not resolve back to this IP (weak signal) |
| Forward Hostnames | proxy-ca002-san81.ahrefs.net |
🔐 DNS Hygiene
| Hygiene Score | 40% (Fair) |
| SPF | Not configured |
| DMARC | Not configured |
| FCrDNS | Not verified |
| DNSSEC | Valid |
| CAA | Present |
☁️ Network Classification
| Infrastructure | Infrastructure / Datacenter |
| Service Purpose | Firewalled / No Services |
| Network Tier | Tier 3 — Basic operator with some routing infrastructure |
🔌 Services & Open Ports
| Port | Service | Protocol | Banner |
|---|---|---|---|
| No open ports detected | |||
| Closed Ports | 22, 25, 80, 443, 3389, 8080, 8443 (0 open / 7 scanned) | ||
| Server | — |
| HTTP Title | — |
🔐 TLS Certificate
| SANs | None |
| Valid From | — |
| Valid Until | — |
🎯 Confidence Breakdown
Per-dimension confidence scores based on source diversity and data freshness
| Dimension | Score | Sources | Observations |
|---|---|---|---|
| threat | 26% | 2 | 4 |
| routing | 27% | 2 | 3 |
| services | 12% | 2 | 2 |
| ownership | 36% | 3 | 5 |
| reputation | 28% | 1 | 3 |
| geolocation | 35% | 2 | 3 |
| Overall | 27% | 12 | 20 |
| Data Coherence | Mostly Consistent (80%) — 1 contradiction(s) |
| Attribution | Low (35%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-05-13 00:39:36 UTC |
| Last Seen | 2026-06-27 22:25:12 UTC |
| Profile Built | 2026-06-28 22:30:40 UTC |
| Data Freshness | Live |
| Signal Types | 24 |
| Total Observations | 31 |
Full dossier details are available via our API.