ABUSE.MOM
THREAT REPORT

IP Threat Report
13.231.39.243

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-10-26 08:49:29
First seen: 2026-10-07 10:47:21
Last seen: 2026-10-11 01:04:08
78

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 78/100. Total malicious requests observed: 70.

BURSTMETHODREFERERUA_CHANGED
01

Geolocation & Classification

IP Address
13.231.39.243
Type
Hosting
Country
🇯🇵 Japan
City
Tokyo
ISP
Amazon Technologies Inc.
Organization
AWS EC2 (ap-northeast-1)
Autonomous System
AS16509 Amazon.com, Inc.
Hit Count
70
02

Detection Signatures

SignatureDescriptionPointsSeverity
Burst 5/2sAbnormally fast request rate — automated scanning+35
Foreign refererReferer from unrelated external domain+10
POST seenBehavioral anomaly detected by automated analysis+8
UA changedMultiple User-Agents — bot rotation technique+25
Σ = 78
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

2026-10-07 10:47:21
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
Burst 5/2s (+35), Foreign referer (+10), POST seen (+8)
2026-10-11 01:04:08
Last malicious request observed
Total score reached: 78/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

Amazon Technologies Inc.
AS16509 · 🇯🇵 Japan

We have detected 3947 malicious IPs from this autonomous system.

View all IPs from AS16509 →
06

Recommendations

Actions taken & recommended

  • IP 13.231.39.243 is blocked at application level (HTTP 403)
  • Consider blocking at firewall level (iptables/CSF) to reduce server load
  • Report abuse to the network provider via their abuse contact
  • Ensure sensitive files (.env, .git, backups) are not accessible from the web

🌊 Flood / DDoS Mitigation

Implement limit_req_zone in nginx. Deploy CDN with DDoS protection. Configure SYN cookies and connection tracking to throttle 13.231.39.243.

🤖 Bot Detection

Address UA spoofing from 13.231.39.243: maintain blocklist of known malicious UA strings, require consistent UA across sessions, implement TLS fingerprinting.

09

Blacklist Status (DNSBL)

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

✓ Clean
dnsbl.dronebl.org
✓ Clean
zen.spamhaus.org
✓ Clean
bl.blocklist.de
✓ Clean
cbl.abuseat.org
✓ Clean
spam.dnsbl.sorbs.net
✓ Clean
b.barracudacentral.org
✓ Clean
psbl.surriel.com

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

10

Threat Analysis

13.231.39.243 has been assigned a threat score of 78/100 (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:

Request FloodingUser-Agent Anomaly

📊 Threat Analysis

Threat intelligence analysis has linked 13.231.39.243 to malicious activity originating from Tokyo, Japan, operating on the network of Amazon Technologies Inc.. The address has been under observation since its initial detection. The address has been active for 3 days in our monitoring system, producing 70 flagged requests at a rate of ~23.3/day. The IP is classified as hosting/datacenter infrastructure, commonly associated with rented servers used for automated attack campaigns, botnet command-and-control, or vulnerability scanning at scale. Two attack patterns were identified (Request Flooding and User-Agent Anomaly), suggesting a semi-automated campaign that targets multiple vulnerabilities. Japan currently accounts for 1,342 blocked IPs in our database, making it a major source of malicious traffic. A threat score of 78/100 places this IP in the high-risk category. Blocking at the firewall level is recommended.

This IP belongs to a hosting or data center provider. Malicious traffic from hosting infrastructure often originates from compromised VPS instances, rented servers used for scanning campaigns, or abused free-tier cloud accounts. Hosting providers typically respond to abuse reports within 24-72 hours.

11

Related Threats

🇯🇵 Top threats from Japan

103.163.220.216 (340)35.189.151.182 (320)168.110.63.243 (320)168.110.58.114 (320)129.225.172.187 (310)View all →

🏢 Same network: AS16509

15.220.152.241 (320)18.219.106.176 (315)3.26.255.172 (308)3.26.98.5 (308)35.180.172.183 (298)View all →
12

Security Intelligence

💡 DDoS Mitigation Approaches

Distributed denial of service attacks overwhelm infrastructure with traffic volume. Effective mitigation combines always-on traffic scrubbing, anycast network distribution, rate limiting, and the ability to quickly scale absorption capacity during attacks.

💡 Submarine Cable and Internet Exchange Points

Internet traffic routing through a limited number of submarine cables and exchange points creates natural chokepoints. Understanding these routing patterns helps explain geographic clustering of certain attack types and latency-based scanning behaviors.

🔍 Check Any IP Address

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