138.91.23.81
IP Intelligence Briefing: 138.91.23.81/32
Date: 2026-06-07
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**1. Core Profile**
- Risk Rating: Low Risk (Score: 25)
- Ownership: Microsoft Corp (ASN 8075)
- Geolocation: Osaka, Japan (34.69°N, 135.5°E)
- Network Role: Microsoft Azure cloud infrastructure (firewalled, no public services)
- Threat Indicators: No malicious activity detected (no blacklists, campaigns, or abuse signals).
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**2. Observation History**
- Recent Activity (June 7, 2026):
- Confirmed as a Microsoft Azure cloud compute instance (non-residential, non-Tor).
- DNSSEC validation active; route stability flagged (potential transient BGP issues).
- No sustained threat signals or anomalous behavior.
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**3. Network Relationships**
- Linked Entities:
- Directly tied to Microsoft’s network infrastructure (multiple relationships).
- No external subnets, hostnames, or organizations linked.
- Implication: Likely a legitimate Azure server with no peer relationships.
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**4. Subnet Analysis**
- Subnet: 138.91.23.81/24
- Neighbor Data:
- No active IPs detected in the subnet (0 neighbors).
- Subnet abuse density: 0 (clean).
- Context: Isolated cloud instance; no neighboring IPs to analyze.
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**5. Threat Assessment**
- No Malicious Indicators:
- No DNS, TLS, or service anomalies.
- No spam, phishing, or malware campaigns associated.
- Control Plane:
- DNSSEC valid; route stability issues noted but not indicative of compromise.
- No DNSBL listings or honeypot activity.
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**6. Recommendations**
- Monitoring: Track BGP route stability for Microsoft Azure infrastructure.
- Firewall: Allow traffic based on Azure’s security best practices (no blocking required).
- Context: Legitimate Microsoft-owned IP; no immediate action needed.
Conclusion: 138.91.23.81 is a low-risk Microsoft Azure cloud server with no malicious activity detected. No further investigation required unless anomalous behavior emerges.
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*Generated by IPDebrief Intelligence Platform*
This summary was generated by AI and may contain inaccuracies. Verify critical details independently.
🏢 Ownership & Registration
| Organization | Microsoft Corp |
| ASN | AS8075 |
| Network Name | — |
| CIDR Block | — |
| RIR | ARIN |
| Country | — |
| Abuse Contact | Available via RDAP |
🌐 DNS Intelligence
| PTR Record | No PTR |
| Forward Confirmed | No — PTR hostname does not resolve back to this IP (weak signal) |
🔐 DNS Hygiene
| Hygiene Score | 20% (Poor) |
| SPF | Not configured |
| DMARC | Not configured |
| FCrDNS | Not verified |
| DNSSEC | Valid |
| CAA | Not configured |
☁️ Network Classification
| Infrastructure | Infrastructure / Datacenter |
| Service Purpose | Firewalled / No Services |
| Network Tier | Hosting — Infrastructure provider without advanced routing |
🔌 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 | 20% | 2 | 4 |
| routing | 8% | 1 | 1 |
| services | 12% | 2 | 2 |
| ownership | 17% | 2 | 3 |
| reputation | 24% | 1 | 3 |
| geolocation | 33% | 2 | 3 |
| Overall | 19% | 10 | 16 |
| Data Coherence | Consistent (100%) |
| Attribution | Moderate (50%) |
| OwnershipFCrDNSGeo ConsensusGeo PlausibleIRR MatchRPKI Valid |
📅 Observation Timeline 🔄 Live
| First Seen | 2026-05-15 20:46:41 UTC |
| Last Seen | 2026-06-28 02:41:47 UTC |
| Profile Built | 2026-06-28 20:48:06 UTC |
| Data Freshness | Live |
| Signal Types | 20 |
| Total Observations | 23 |
Full dossier details are available via our API.