165.73.137.83📋 Copy

# IPDEBRIEF INTELLIGENCE BRIEFING

Subject: 165.73.137.83/32

Classification: High Risk

Date: 2026-07-27

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## EXECUTIVE SUMMARY

IP 165.73.137.83 presents an elevated threat profile with a risk score of 80/100. The address is owned by individual Nico van der Westhuizen (ASN 328257) within the 165.73.137.0/24 block in Kleinmond, Western Cape, South Africa. The IP exhibits firewalled status with no active services detected, though it maintains a significant presence on DNS blacklists across 4 of 8 total listings.

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## OWNERSHIP AND ATTRIBUTION

• Organization: Nico van der Westhuizen
• ASN: 328257
• CIDR Block: 165.73.137.0 - 165.73.137.255
• RIR: ARIN
• Registration Status: Individual ownership with minimal operator score (0.1304)

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## GEOLOCATION

• Country: South Africa (ZA)
• Region: Western Cape
• City: Kleinmond
• Coordinates: -30.56° latitude, 22.94° longitude
• Geolocation Confidence: 52% (800km accuracy radius)
• Network Path: 21 hops via Comcast and HE networks

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## THREAT INDICATORS

• Risk Score: 80/100 (High Risk)
• DNSBL Listings: 4/8 total blacklists
• Service Status: Firewalled / No Services
• Known Attackers: No
• Tor Exit Node: No
• Campaign Associations: None identified
• Threat Feeds: No matches

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## NETWORK NEIGHBORHOOD ANALYSIS

The /24 subnet (165.73.137.0/24) contains 15 total sibling IPs with the following risk distribution:

• High Risk: 0 IPs
• Medium Risk: 11 IPs
• Low Risk: 3 IPs

Notable Sibling Addresses:

Subnet Abuse Density: 0.0667 (6.67%)

Subnet Classification: Mostly Clean

Inherited Risk: 2

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## OBSERVATION HISTORY

Fourteen signal observations recorded through 2026-07-27:

• Recent Subnet Classification: Mostly Clean (abuse density 0.0667)
• Ownership Changes: None (0 changes)
• Threat Persistence: Not identified as persistently malicious
• Operator Score: 0.1304 (Minimal)
• DNSSEC Validation: Valid

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## NETWORK BEHAVIOR

• Open Ports: None detected
• HTTP Services: None
• TLS Certificates: None
• PTR Records: None
• Forward Resolution: Not confirmed
• Hosted Domains: None (0 domains)
• Email Authentication: SPF and DMARC not configured
• Honeypot Hits: 0
• Enumeration Strikes: 0

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## RECOMMENDED ACTIONS

IMMEDIATE (Critical Severity)

1. Increase logging verbosity for all traffic from this IP address

2. Review recent activity from 165.73.137.83 in SIEM systems

FIREWALL IMPLEMENTATION

CONTINUOUS MONITORING

• Monitor for lateral movement to sibling IPs in 165.73.137.0/24
• Track DNSBL listing changes
• Review for service activation on this IP address

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## RISK ASSESSMENT

This IP address warrants elevated monitoring due to its high risk score (80/100) and DNSBL presence. While the subnet maintains a "mostly clean" classification with low abuse density, the individual IP exhibits characteristics consistent with potential abuse activity. The firewalled status with no active services suggests either a dormant endpoint or actively misconfigured infrastructure.

Recommended Handling: Block at perimeter firewall with logging enabled. Consider blocking entire /24 subnet if business impact permits, given 11 of 15 sibling IPs show medium-level risk scores.

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