157.55.39.51📋 Copy

# IP INTELLIGENCE BRIEFING

Target: 157.55.39.51/32

Classification: LOW RISK - Legitimate Infrastructure

Date: 2026-06-20

Analyst: IPDebrief Intelligence Team

## Executive Summary

IP 157.55.39.51 is identified as Microsoft Corporation infrastructure within the Azure cloud platform (ASN 8075). The address resolves to Microsoft infrastructure in Quincy, WA and is associated with MSN search bot operations. The IP carries a low-risk profile (risk score: 25) with no active threat indicators or blacklist associations. No blocking action recommended.

## Infrastructure Profile

## Threat Assessment

• Reputation Score: 25 (Low Risk)
• Abuse Confidence: Not applicable (legitimate infrastructure)
• Blacklist Count: 0
• Tor Exit Node: No
• Known Attacker: No
• Spam Source: No
• Campaign Association: None identified

Control Plane Indicators:

• DNSSEC Valid: Yes
• CAA Records: Present
• Route Stability: Unstable (route changes observed in 30-day period)
• DNSBL Listed: 1 of 8 lists

## Network Neighborhood Analysis

Subnet: 157.55.39.0/24

Total Neighbors: 30

Abuse Density: 0.3793 (moderate)

Classification: Mixed

Risk Distribution:

• High Risk: 0
• Medium Risk: 12
• Low Risk: 18

Notable neighbor risk scores range from 0-50, with the majority showing Microsoft infrastructure characteristics (authority score: 60). The subnet exhibits typical Azure cloud infrastructure patterns with mixed operational profiles.

## Historical Observations (21 records)

Recent signal history confirms consistent Microsoft Azure cloud classification. Geographic inferences consistently point to Quincy, WA region. DNS records for msn.com domain confirmed across multiple observations. No temporal degradation in infrastructure reputation observed.

Key Temporal Signals:

• Cloud infrastructure classification: Consistent
• Geographic resolution: Quincy, WA (WA region)
• DNS associations: msn.com domain
• Operator score: 0.3478 (Basic)

## Relationship Graph

Identified Associations (39 total):

• DNS Associations: Multiple entries for msnbot-157-55-39-51.search.msn.com
• Network Classification: MSFT-GFS (Microsoft network)
• Infrastructure Type: Microsoft Azure datacenter

## Security Recommendations

No blocking action required. This IP is legitimate Microsoft cloud infrastructure associated with MSN search indexing operations.

Monitoring Considerations:

• Track subnet-level activity for 157.55.39.0/24 to identify any anomalous patterns
• Monitor for unauthorized DNS record changes
• Observe for any unexpected port exposure or service banners

Allowed Operations:

• Standard outbound traffic permitted
• DNS queries to msn.com domain acceptable
• No special firewall restrictions recommended

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*Data sourced from IPDebrief intelligence platform. All indicators based on observed network signals and threat intelligence feeds.*

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