ABUSE.MOM
THREAT REPORT

IP Threat Report
51.91.151.213

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-05-21 21:18:33
First seen: 2026-03-23 03:00:07
Last seen: 2026-03-23 03:00:07
105

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 105/100. Total malicious requests observed: 1.

UA_CHANGEDBURSTREFERER
01

Geolocation & Classification

IP Address
51.91.151.213
Type
Hosting
Country
🇫🇷 France
City
Roubaix
ISP
OVH SAS
Organization
OVH
Autonomous System
AS16276 OVH SAS
Hit Count
1
02

Detection Signatures

SignatureDescriptionPointsSeverity
UA changed for same IPMultiple User-Agents — bot rotation technique+25
Burst: 7 req / 2sAbnormally fast request rate — automated scanning+35
Burst: 11 req / 10sAbnormally fast request rate — automated scanning+35
Foreign referer seenReferer from unrelated external domain+10
Σ = 105
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

2026-03-23 03:00:07
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
UA changed for same IP (+25), Burst: 7 req / 2s (+35), Burst: 11 req / 10s (+35)
2026-03-23 03:00:07
Last malicious request observed
Total score reached: 105/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

OVH SAS
AS16276 · 🇫🇷 France
06

Recommendations

Actions taken & recommended

  • IP 51.91.151.213 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

🤖 User-Agent Anomaly Defense

IP 51.91.151.213 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.

🌊 Traffic Flood Defense

IP 51.91.151.213 is generating excessive traffic. Limit connections per source IP. Enable geographic blocking if traffic from this region is unexpected.

09

Blacklist Status (DNSBL)

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

⛔ LISTED
b.barracudacentral.org
✓ Clean
ix.dnsbl.manitu.net
✓ Clean
dnsbl.sorbs.net
✓ Clean
bl.spamcop.net
✓ Clean
zen.spamhaus.org
✓ Clean
dnsbl-1.uceprotect.net
✓ Clean
psbl.surriel.com
✓ Clean
truncate.gbudb.net

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

10

Threat Analysis

51.91.151.213 has been assigned a threat score of 105/100 (Critical). This is a critical-level threat. Systems administrators should treat this IP as hostile and block all inbound connections without exception.

The following attack categories were identified:

User-Agent AnomalyRequest Flooding

📊 Threat Analysis

Our monitoring infrastructure has identified 51.91.151.213, geolocated to Roubaix, France, operating on the network of OVH SAS, as a source of suspicious network activity. The address has been active for 1 days in our monitoring system, producing 1 flagged requests at a rate of ~1/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 dual attack vectors of User-Agent Anomaly combined with Request Flooding indicate a coordinated assault rather than opportunistic scanning. With 125 flagged addresses, France represents a significant presence in our threat database. A score of 105/100 places this address in the top tier of severity. Block and investigate any historical connections.

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 France

185.177.72.11 (348)185.177.72.67 (348)185.177.72.10 (348)185.177.72.69 (348)185.177.72.29 (348)View all →

🏢 Same network: AS16276

51.38.99.224 (280)151.243.236.245 (275)54.37.156.148 (273)146.59.235.113 (263)51.83.98.78 (255)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.

💡 VPN Exit Node Reputation

VPN exit nodes aggregate traffic from many users, creating mixed reputation profiles. While legitimate users seek privacy, attackers exploit VPN services to anonymize malicious activity, making IP-based blocking of VPN nodes a complex policy decision.

🔍 Check Any IP Address

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