ABUSE.MOM
THREAT REPORT

IP Threat Report
45.156.128.51

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-05-30 09:21:15
First seen: 2026-03-06 14:00:05
Last seen: 2026-05-30 09:07:01
108

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 108/100. Total malicious requests observed: 402.

BOT_UAMETHODRATIO_404REFERERUA_CHANGED
01

Geolocation & Classification

IP Address
45.156.128.51
Type
Residential
Country
🇳🇱 Netherlands
City
Amsterdam
ISP
NSEC - Sistemas Informaticos, S.A.
Organization
Inap AMS
Autonomous System
AS211680 NSEC - Sistemas Informaticos, S.A.
Hit Count
402
02

Detection Signatures

SignatureDescriptionPointsSeverity
404 ratio 40-60%Majority of requests returned 404 — enumeration+15
404 ratio >= 60%Majority of requests returned 404 — enumeration+25
Foreign refererReferer from unrelated external domain+10
Foreign referer seenReferer from unrelated external domain+10
POST requests presentBehavioral anomaly detected by automated analysis+8
POST seenBehavioral anomaly detected by automated analysis+8
UA bot: pythonKnown bot/crawler User-Agent detected+40
UA changedMultiple User-Agents — bot rotation technique+25
UA changed for same IPMultiple User-Agents — bot rotation technique+25
Σ = 166
03

Observed Activity

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

[redacted]
GET
/
200
Requests shown: 1 · HTTP 404: 0 · Dangerous patterns: 0

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

04

Timeline

2026-03-06 14:00:05
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
404 ratio 40-60% (+15), 404 ratio >= 60% (+25), Foreign referer (+10)
2026-05-30 09:07:01
Last malicious request observed
Total score reached: 108/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

NSEC - Sistemas Informaticos, S.A.
AS211680 · 🇳🇱 Netherlands
06

Recommendations

Actions taken & recommended

  • IP 45.156.128.51 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 45.156.128.0/24
  • Report abuse to the network provider via their abuse contact
  • Ensure sensitive files (.env, .git, backups) are not accessible from the web

🔎 Path Enumeration Protection

Block scanning from 45.156.128.51: rate-limit 404 responses per IP, deploy a honeypot 404 page, ensure no backup files are web-accessible.

🤖 User-Agent Anomaly Defense

IP 45.156.128.51 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.

07

Neighbors in 45.156.128.0/24

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.

✓ Clean
bl.spamcop.net
✓ Clean
b.barracudacentral.org
✓ Clean
dnsbl.dronebl.org
✓ Clean
bl.blocklist.de
✓ Clean
zen.spamhaus.org
✓ Clean
spam.dnsbl.sorbs.net

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

10

Threat Analysis

45.156.128.51 has been assigned a threat score of 108/100 (Critical). A score this high marks a critical threat actor. This address has demonstrated persistent, aggressive malicious behavior across multiple detection vectors.

The following attack categories were identified:

Path EnumerationUser-Agent Anomaly

📊 Threat Analysis

IP address 45.156.128.51 has been traced to Amsterdam, Netherlands, operating on the network of NSEC - Sistemas Informaticos, S.A.. Our threat detection systems have flagged this address based on observed malicious behavior patterns. Our sensors captured 402 malicious requests from this address across a 84-day span, reflecting a sustained attack cadence of ~4.8 requests per day. The address is classified as residential, meaning it likely belongs to an end-user ISP connection. Malicious activity from residential IPs typically indicates device compromise or botnet membership. The dual attack vectors of Path Enumeration combined with User-Agent Anomaly indicate a coordinated assault rather than opportunistic scanning. Netherlands currently accounts for 42 blocked IPs in our database, making it a notable source of malicious traffic. With a threat score of 108/100, this IP is among the most dangerous addresses in our database. Immediate and complete blocking is strongly 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

🇳🇱 Top threats from Netherlands

45.156.128.108 (145)45.156.128.155 (140)45.156.128.176 (130)45.156.128.61 (128)45.156.128.102 (125)View all →

🏢 Same network: AS211680

45.156.128.108 (145)45.156.128.155 (140)45.156.128.176 (130)45.156.129.176 (130)45.156.128.61 (128)View all →
12

Security Intelligence

💡 HTTP Header Analysis for Threat Detection

Examining HTTP headers beyond User-Agent reveals attack tools and automated scripts. Missing standard headers, unusual ordering, non-standard values, and inconsistencies with claimed client identity all serve as reliable detection signals.

💡 Vulnerability Scanning Explained

Vulnerability scanning is the automated process of probing web applications for known weaknesses. Attackers use tools like Nuclei, Nikto, and ZAP to test thousands of hosts per hour, looking for exposed configuration files, outdated software, and default credentials.

🔍 Check Any IP Address

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