ABUSE.MOM
THREAT REPORT

IP Threat Report
158.158.51.104

ABUSE.MOM — BEHAVE OR GET EXPOSED

Generated: 2026-05-22 05:47:51
First seen: 2026-04-01 15:00:06
Last seen: 2026-04-01 19:00:07
230

⛔ Verdict: BLOCK

This IP address has been classified as a source of malicious automated activity. Threat score: 230/100. Total malicious requests observed: 4.

UA_SUSDANGER_PATHRATIO_404REDIRECT_PROBEBURST
01

Geolocation & Classification

IP Address
158.158.51.104
Type
Hosting
Country
🇪🇸 Spain
City
Madrid
ISP
Microsoft Corporation
Organization
Microsoft Azure Cloud (spaincentral)
Autonomous System
AS8075 Microsoft Corporation
Hit Count
4
02

Detection Signatures

SignatureDescriptionPointsSeverity
UA suspicious (short/empty)Behavioral anomaly detected by automated analysis+15
Danger strong hits: 2High-risk paths: shells, RCE vectors, exploits+50
Danger medium hits: 134Medium-risk: admin panels, config files+60
404 ratio 40-60%Majority of requests returned 404 — enumeration+15
Probe pattern 302->404 same pathBehavioral anomaly detected by automated analysis+20
Burst: 46 req / 2sAbnormally fast request rate — automated scanning+35
Burst: 134 req / 10sAbnormally fast request rate — automated scanning+35
Danger strong hits: 3High-risk paths: shells, RCE vectors, exploits+75
Burst: 28 req / 2sAbnormally fast request rate — automated scanning+35
Burst: 88 req / 10sAbnormally fast request rate — automated scanning+35
Burst: 27 req / 2sAbnormally fast request rate — automated scanning+35
Burst: 86 req / 10sAbnormally fast request rate — automated scanning+35
Burst: 43 req / 2sAbnormally fast request rate — automated scanning+35
Burst: 154 req / 10sAbnormally fast request rate — automated scanning+35
Σ = 515
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

2026-04-01 15:00:06
First malicious request detected
IP entered monitoring from server access logs
During observation
Multiple detection signatures triggered
UA suspicious (short/empty) (+15), Danger strong hits: 2 (+50), Danger medium hits: 134 (+60)
2026-04-01 19:00:07
Last malicious request observed
Total score reached: 230/100
Next cycle
IP blocked — all subsequent requests denied (HTTP 403)
Added to blocklist automatically
05

Network Provider

Microsoft Corporation
AS8075 · 🇪🇸 Spain
06

Recommendations

Actions taken & recommended

  • IP 158.158.51.104 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 158.158.51.0/24
  • 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 158.158.51.104 shows suspicious UA behavior. Block empty User-Agent requests. Implement JavaScript-based bot detection for sensitive endpoints.

🔎 Directory Scan Defense

IP 158.158.51.104 is enumerating directories. Configure fail2ban apache-404 jail after 10+ 404 errors. Disable directory listings. Normalize all 404 responses.

🌊 Flood / DDoS Mitigation

Implement limit_req_zone in nginx. Deploy CDN with DDoS protection. Configure SYN cookies and connection tracking to throttle 158.158.51.104.

07

Neighbors in 158.158.51.0/24

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.

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

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

10

Threat Analysis

158.158.51.104 has been assigned a threat score of 230/100 (Critical). This places it in the critical threat category. Immediate blocking is strongly advised across all network perimeters.

The following attack categories were identified:

User-Agent AnomalyPath EnumerationRequest Flooding

📊 Threat Analysis

IP address 158.158.51.104 has been traced to Madrid, Spain, operating on the network of Microsoft Corporation. Our threat detection systems have flagged this address based on observed malicious behavior patterns. During its 1-day observation window, we recorded 4 hostile requests from this IP — roughly 4 per day on average. Operating from datacenter infrastructure, this IP is typical of addresses used in organized attack operations. Cloud and VPS providers are commonly exploited as launching platforms for automated scanning. 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 Spain, positioning it as a significant contributor to global threat activity. A score of 230/100 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 Spain

158.173.36.160 (305)212.30.33.72 (305)45.67.99.32 (305)158.158.33.103 (280)158.158.105.51 (280)View all →

🏢 Same network: AS8075

74.241.249.229 (340)4.182.24.88 (285)20.65.61.3 (283)4.205.39.97 (283)20.29.71.103 (283)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.

💡 IPv6 Scanning Challenges

The vast IPv6 address space makes traditional sequential scanning impractical. However, attackers use DNS records, certificate transparency logs, and predictable address patterns to identify active IPv6 hosts, adapting their techniques to the expanded address space.

🔍 Check Any IP Address

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