121.233.135.81📋 Copy

# IP INTELLIGENCE BRIEFING

Subject: 121.233.135.81/32

Classification: Moderate Risk

Date: 2026-07-31

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## EXECUTIVE SUMMARY

IP 121.233.135.81 is a moderate risk endpoint (risk score: 50) operating on China Telecom mobile network infrastructure within the CHINANET-JS network block (121.224.0.0/12, ASN 4134). The IP exhibits no active threat indicators, no open services, and is classified as mobile/connected device. While not directly malicious, the IP's network context warrants monitoring due to its residential mobile classification and presence on 2 DNSBL entries.

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## TECHNICAL PROFILE

• IP Address: 121.233.135.81/32
• Risk Score: 50/100 (Moderate)
• ASN: 4134 (Chinanet Hostmaster)
• Organization: CHINANET-JS, China Telecom Corp. Ltd.
• RIR: APNIC
• CIDR Block: 121.224.0.0/12
• Geolocation: China (CN), coordinates 35.86°N, 104.2°E (2500km accuracy radius)
• Network Type: Mobile (China Telecom LTE/5G, MCC: 460, MNC: 03)
• Status: Firewalled / No Services Detected
• DNS: No PTR records, no forward resolution

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## THREAT INDICATORS

• Known Attacker: No
• Spam Source: No
• Tor Exit Node: No
• Blacklist Count: 0 threat feeds, 2 DNSBL listings
• Campaigns: None identified
• Services: No open ports detected
• TLS/Certificates: None
• Abuse Confidence Score: Not applicable

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## NETWORK CONTEXT & NEIGHBORHOOD ANALYSIS

Subnet: 121.233.135.81/24

• Abuse Density: 0.2 (Low)
• Classification: Mostly clean
• Total Siblings: 5 (4 active)

Neighbor Risk Distribution:

One neighboring IP (121.233.135.19) shares the same moderate risk profile as the subject IP.

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## OBSERVATION HISTORY

Total Observations: 15 signals recorded

• Latest Signal: 2026-07-31T03:08:21Z
• Geolocation Signals: Confirmed China (CN) with multi-signal inference
• Ownership Signals: Consistent with Chinanet Hostmaster / APNIC
• Threat Persistence: None detected
• Route Stability: Unstable (route changes observed in 30-day window)
• ICMP Validation: Blocked (unable to validate geolocation)

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## RELATIONSHIP GRAPH

• Network Associations: CHINANET-JS (2 relationships)
• No Direct Links: No associated hostnames, organizations, or certificates identified
• No Correlated IPs: Zero correlated IPs in relationship graph

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## RECOMMENDED ACTIONS

SOC Analyst Guidance:

1. Monitor - IP shows moderate risk with mobile carrier classification; no immediate blocking required

2. Correlate - Check if traffic patterns align with other mobile endpoints in 121.233.135.0/24

3. DNSBL Review - Investigate the 2 DNSBL listings to determine if they impact deliverability or reputation

4. Baseline - Establish baseline traffic for China Telecom mobile endpoints to distinguish legitimate vs. anomalous behavior

No immediate firewall rules recommended. The IP is not flagged as malicious, but warrants continued monitoring due to its mobile infrastructure classification and moderate risk score.

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Report Generated: 2026-07-31

Data Source: IPDebrief Intelligence Platform

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