IP Threat Report
51.103.133.91
ABUSE.MOM — BEHAVE OR GET EXPOSED
Geolocation & Classification
Detection Signatures
| Signature | Description | Points | Severity |
|---|---|---|---|
| UA suspicious (short/empty) | Behavioral anomaly detected by automated analysis | +15 | |
| Danger strong hits: 37 | High-risk paths: shells, RCE vectors, exploits | +100 | |
| Danger medium hits: 326 | Medium-risk: admin panels, config files | +60 | |
| Probe pattern 302->404 same path | Behavioral anomaly detected by automated analysis | +20 | |
| Burst: 51 req / 2s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 175 req / 10s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 43 req / 2s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 106 req / 10s | Abnormally fast request rate — automated scanning | +35 | |
| Danger strong hits: 26 | High-risk paths: shells, RCE vectors, exploits | +100 | |
| 404 ratio 40-60% | Majority of requests returned 404 — enumeration | +15 | |
| Burst: 49 req / 2s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 148 req / 10s | Abnormally fast request rate — automated scanning | +35 | |
| Danger strong hits: 50 | High-risk paths: shells, RCE vectors, exploits | +100 | |
| Danger medium hits: 489 | Medium-risk: admin panels, config files | +60 | |
| Burst: 50 req / 2s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 145 req / 10s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 42 req / 2s | Abnormally fast request rate — automated scanning | +35 | |
| Burst: 129 req / 10s | Abnormally fast request rate — automated scanning | +35 |
Observed Activity
Reconstructed HTTP requests from server access logs. Target domains redacted for security.
* Typical request patterns for detected signatures. Actual target domains are redacted.
Timeline
Network Provider
Recommendations
Actions taken & recommended
- IP 51.103.133.91 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 51.103.133.91 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.
🔎 Path Enumeration Protection
Block scanning from 51.103.133.91: rate-limit 404 responses per IP, deploy a honeypot 404 page, ensure no backup files are web-accessible.
🌊 Traffic Flood Defense
IP 51.103.133.91 is generating excessive traffic. Limit connections per source IP. Enable geographic blocking if traffic from this region is unexpected.
Blacklist Status (DNSBL)
This IP was checked against major DNS-based blacklists used by mail servers and firewalls worldwide.
Checked: Spamhaus, SpamCop, Barracuda, SORBS, CBL, UCEProtect. Results may change over time.
Threat Analysis
51.103.133.91 has been assigned a threat score of 280/100 (Critical). This represents a critical risk level. Our detection systems have flagged multiple high-confidence indicators of malicious intent from this address.
The following attack categories were identified:
📊 Threat Analysis
51.103.133.91 is registered in Zurich, Switzerland, operating on the network of Microsoft. This IP first appeared in our threat feeds after triggering multiple behavioral detection signatures. The address has been active for 1 days in our monitoring system, producing 5 flagged requests at a rate of ~5/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. Our records show 102 malicious IPs originating from Switzerland, positioning it as a significant contributor to global threat activity. At 280/100, 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.
Related Threats
🇨🇭 Top threats from Switzerland
51.107.69.151 (280)20.250.10.152 (280)20.203.180.135 (280)20.203.136.132 (280)20.203.129.217 (280)View all →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.
💡 HTTP/2 and HTTP/3 Security Implications
Modern HTTP protocols introduce new attack surfaces including stream multiplexing abuse, header compression attacks (HPACK bombing), and rapid reset attacks. Security tools must evolve to handle these protocol-specific threats effectively.