ABUSE.MOM
THREAT REPORT

IP Threat Report
72.251.216.21

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-10-25 06:50:22
First seen: 2026-09-27 01:36:51
Last seen: 2026-10-04 00:52:29
165

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 165/100. Total malicious requests observed: 155.

BURSTDANGER_PATHRATIO_404REDIRECT_PROBEREFERERUA_CHANGED
01

Geolocation & Classification

IP Address
72.251.216.21
Type
Hosting
Country
🇭🇷 HR
City
Zagreb
ISP
Proton AG
Organization
PV-SL-HOSTED-Zagreb
Autonomous System
AS208172 Proton AG
Hit Count
155
02

Detection Signatures

SignatureDescriptionPointsSeverity
404 ratio 40-60%Majority of requests returned 404 — enumeration+15
Burst 5/2sAbnormally fast request rate — automated scanning+35
Danger medium hits: 10Medium-risk: admin panels, config files+60
Danger medium hits: 5Medium-risk: admin panels, config files+50
Foreign refererReferer from unrelated external domain+10
Probe 302→404Behavioral anomaly detected by automated analysis+20
UA changedMultiple User-Agents — bot rotation technique+25
Σ = 215
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

2026-09-27 01:36:51
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
404 ratio 40-60% (+15), Burst 5/2s (+35), Danger medium hits: 10 (+60)
2026-10-04 00:52:29
Last malicious request observed
Total score reached: 165/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

Proton AG
AS208172 · 🇭🇷 HR

We have detected 18 malicious IPs from this autonomous system.

View all IPs from AS208172 →
06

Recommendations

Actions taken & recommended

  • IP 72.251.216.21 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 72.251.216.0/24
  • Report abuse to the network provider via their abuse contact
  • Ensure sensitive files (.env, .git, backups) are not accessible from the web

🔎 Directory Scan Defense

IP 72.251.216.21 is enumerating directories. Configure fail2ban apache-404 jail after 10+ 404 errors. Disable directory listings. Normalize all 404 responses.

🌊 Traffic Flood Defense

IP 72.251.216.21 is generating excessive traffic. Limit connections per source IP. Enable geographic blocking if traffic from this region is unexpected.

🤖 User-Agent Anomaly Defense

IP 72.251.216.21 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.

07

Neighbors in 72.251.216.0/24

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

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

10

Threat Analysis

72.251.216.21 has been assigned a threat score of 165/100 (Critical). With this rating, the IP falls into the critical severity bracket — among the most dangerous addresses in our monitoring database.

The following attack categories were identified:

Path EnumerationRequest FloodingUser-Agent Anomaly

📊 Threat Analysis

IP address 72.251.216.21 has been traced to Zagreb, HR, operating on the network of Proton AG. Our threat detection systems have flagged this address based on observed malicious behavior patterns. Over a period of 6 days, this IP generated 155 malicious requests, averaging approximately 25.8 requests per day. This address belongs to a datacenter or cloud hosting provider. Hosting IPs are frequently leveraged by threat actors who rent cheap VPS instances specifically for conducting attacks. The combination of 3 distinct attack vectors indicates a sophisticated, multi-pronged threat actor deploying automated tools that probe multiple attack surfaces simultaneously. HR currently accounts for 48 blocked IPs in our database, making it a notable source of malicious traffic. At 165/100, this is an extremely high-risk address. All traffic should be considered hostile.

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 HR

149.102.247.132 (255)72.251.216.38 (165)72.251.216.34 (165)72.251.216.17 (165)79.127.144.143 (165)View all →

🏢 Same network: AS208172

159.26.101.60 (255)72.251.216.38 (165)72.251.216.34 (165)72.251.216.17 (165)72.251.216.13 (165)View all →
12

Security Intelligence

💡 SSH Brute Force Defense

SSH servers face constant brute force attacks targeting common usernames and weak passwords. Key-based authentication, fail2ban, non-standard ports, and IP allowlisting dramatically reduce the attack surface. Monitoring auth logs reveals active campaigns and compromised credentials.

💡 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.

🔍 Check Any IP Address

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