ABUSE.MOM
THREAT REPORT

IP Threat Report
205.169.39.100

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-05-29 07:27:19
First seen: 2026-02-25 21:00:05
Last seen: 2026-02-25 21:00:05
70

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 70/100. Total malicious requests observed: 1.

UA_CHANGEDBURSTREFERER
01

Geolocation & Classification

IP Address
205.169.39.100
Type
Residential
Country
🇺🇸 United States
City
Santa Clara
ISP
CenturyLink Communications
Organization
Palo Alto Networks, Inc
Autonomous System
AS3356 Level 3 Parent, LLC
Hit Count
1
02

Detection Signatures

SignatureDescriptionPointsSeverity
UA changed for same IPMultiple User-Agents — bot rotation technique+25
Burst: 5 req / 2sAbnormally fast request rate — automated scanning+35
Foreign referer seenReferer from unrelated external domain+10
Σ = 70
03

Observed Activity

Reconstructed HTTP requests from server access logs. Target domains redacted for security.

[redacted]
GET
/
200
[redacted]
GET
/page
200
Requests shown: 2 · HTTP 404: 0 · Dangerous patterns: 0

* Typical request patterns for detected signatures. Actual target domains are redacted.

04

Timeline

2026-02-25 21:00:05
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
UA changed for same IP (+25), Burst: 5 req / 2s (+35), Foreign referer seen (+10)
2026-02-25 21:00:05
Last malicious request observed
Total score reached: 70/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

CenturyLink Communications
AS3356 · 🇺🇸 United States
06

Recommendations

Actions taken & recommended

  • IP 205.169.39.100 is blocked at application level (HTTP 403)
  • Consider blocking at firewall level (iptables/CSF) to reduce server load
  • Other malicious IPs detected in the same /24 subnet — consider blocking 205.169.39.0/24
  • Report abuse to the network provider via their abuse contact
  • Ensure sensitive files (.env, .git, backups) are not accessible from the web

🤖 User-Agent Anomaly Defense

IP 205.169.39.100 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.

🌊 Flood / DDoS Mitigation

Implement limit_req_zone in nginx. Deploy CDN with DDoS protection. Configure SYN cookies and connection tracking to throttle 205.169.39.100.

07

Neighbors in 205.169.39.0/24

Other blocked IPs from the same /24 subnet — indicates systematic abuse from this network range.

09

Blacklist Status (DNSBL)

This IP was checked against major DNS-based blacklists used by mail servers and firewalls worldwide.

⛔ LISTED
Spamhaus ZEN

Checked: Spamhaus, SpamCop, Barracuda, SORBS, CBL, UCEProtect. Results may change over time.

10

Threat Analysis

205.169.39.100 has been assigned a threat score of 70/100 (High). This score indicates high threat severity. The IP has shown clear patterns of malicious behavior that warrant immediate defensive measures.

The following attack categories were identified:

User-Agent AnomalyRequest Flooding

📊 Threat Analysis

The address 205.169.39.100 originates from Santa Clara, United States, operating on the network of CenturyLink Communications. It was identified through automated analysis of incoming network traffic across monitored endpoints. Our sensors captured 1 malicious requests from this address across a 1-day span, reflecting a sustained attack cadence of ~1 requests per day. This is a residential IP address, suggesting a compromised home device such as a router, smart appliance, or infected workstation participating in a botnet. Two attack patterns were identified (User-Agent Anomaly and Request Flooding), suggesting a semi-automated campaign that targets multiple vulnerabilities. With 172 flagged addresses, United States represents a significant presence in our threat database. A threat score of 70/100 places this IP in the high-risk category. Blocking at the firewall level is recommended.

This IP is classified as residential, suggesting it may belong to a compromised home device, IoT botnet member, or an infected personal computer. Residential IPs involved in attacks often indicate malware infection without the owner's knowledge.

11

Related Threats

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🏢 Same network: AS3356

205.169.39.217 (155)205.169.39.128 (155)205.169.39.71 (155)205.169.39.103 (145)205.169.39.149 (145)View all →
12

Security Intelligence

💡 User-Agent Analysis Techniques

Analyzing User-Agent strings reveals automated tools masquerading as legitimate browsers. Inconsistencies between claimed browser capabilities and actual behavior, impossible version combinations, and known scanner signatures help identify malicious clients.

💡 Botnet Command and Control Evolution

Botnet C2 infrastructure has evolved from centralized IRC channels to resilient peer-to-peer networks, domain generation algorithms, and blockchain-based communication. This evolution makes botnet takedowns increasingly difficult and expensive.

🔍 Check Any IP Address

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