IP & Domain Blocklist
Real-time cybersecurity blocklist with 500M+ malicious IPs and domains from 600+ trusted sources
Comprehensive IP & Domain Blocklist for Cybersecurity
IsMalicious provides the most comprehensive IP blocklist and domain blocklist for modern cybersecurity infrastructure. Our real-time blocklist API protects millions of users from malicious IPs, phishing domains, malware, adware, and tracking threats.
IP Blocklist - 100M+ Malicious IP Addresses
Our malicious IP blocklist contains over 100M verified threatening IP addresses, updated every hour. Protect your network perimeter from cyber attacks with comprehensive IP-based threat intelligence.
Malware Distribution
Block servers hosting ransomware, trojans, and viruses
Phishing Servers
Prevent credential harvesting attacks
Botnet C2
Identify command & control infrastructure
Brute Force
Stop automated attack attempts
DDoS Sources
Mitigate distributed attacks
Spam & Abuse
Filter unwanted network traffic
🌐 Domain Blocklist - 400M+ Malicious Domains by Category
Phishing Blocklist
45M+Block credential harvesting sites and fake login pages. Updated daily with newly registered phishing domains and brand impersonation attempts.
Malware Blocklist
89M+Prevent malware downloads by blocking known distribution domains. Includes ransomware, trojans, viruses, and malicious software hosts.
Adware Blocklist
28M+Block invasive advertising networks and unwanted software promotions. Improve user experience and reduce security risks from adware.
Tracking Blocklist
67M+Protect user privacy by blocking tracking domains, analytics scripts, fingerprinting services, and surveillance networks. GDPR compliant.
💡 Quick API Integration
Integrate our blocklist API in minutes with simple RESTful endpoints. Sub-100ms response times for real-time protection.
// Check if IP is in blocklist
const response = await fetch(
'https://api.ismalicious.com/check?ip=1.2.3.4'
);
const data = await response.json();
if (data.isMalicious) {
// Block the IP
console.log('Blocked:', data.sources);
}
// Check domain
const domainCheck = await fetch(
'https://api.ismalicious.com/check?domain=example.com'
);⚡ Real-Time Blocklist Updates
Unlike static blocklists that update weekly or monthly, our real-time blocklist provides continuous protection with the latest threat intelligence:
Hourly Updates
New threats added within minutes of discovery
600+ Sources
Combined intelligence from commercial and open-source feeds
Multi-Source Validation
Reduce false positives with cross-verification
WebHook Notifications
Get alerted when watched entities change status
🔧 How to Use Our Blocklist API
Firewall Integration
Download our IP blocklist and import into your firewall rules. Supports iptables, pfSense, Cisco ASA, FortiGate, and more. Automatic updates available.
DNS Filtering
Use our domain blocklist with Pi-hole, AdGuard Home, or DNS servers to block malicious domains at the DNS level. Perfect for network-wide protection.
Application Integration
Call our blocklist API from your application code to validate user inputs, URLs, and network connections in real-time. Available in all major languages.
SIEM Enrichment
Enrich security events with our threat intelligence to prioritize alerts and accelerate incident response. Compatible with Splunk, ELK, QRadar.
📊 Blocklist Coverage by Category
🆓 Free Blocklist Access
Start protecting your infrastructure today with our free tier - no credit card required:
Why Blocklists Are Essential for Modern Cybersecurity
Blocklists are a foundational layer of network security. While advanced threat detection systems look for suspicious behavior, blocklists provide immediate protection by preventing communication with known malicious infrastructure. A well-maintained blocklist stops threats before they can execute - malware can't download if the distribution server is blocked, phishing pages can't steal credentials if the domain is blocked, and C2 communication can't occur if the botnet server is blocked. The key is freshness. Cyber criminals constantly rotate infrastructure. A blocklist that updates weekly may miss 80% of active threats. Our real-time updates ensure you're protected against the latest threats, not just historical ones.
Multi-Source Validation Reduces False Positives
False positives are the enemy of security tools. Block a legitimate site and users lose trust in the protection. Allow a malicious site and you've failed at your primary job. Finding the right balance is crucial. Our blocklist aggregates data from 600+ threat intelligence sources. When multiple independent sources identify an entity as malicious, we have high confidence in the classification. Single-source reports are flagged for additional verification before inclusion. This multi-source validation approach achieves a false positive rate below 0.01% while maintaining comprehensive coverage. You can trust our blocklist to block threats without interfering with legitimate business operations.
Defense in Depth: Layered Blocklist Protection
Effective security requires multiple layers of protection. Blocklists can be deployed at various points in your infrastructure: • Perimeter Firewall: Block malicious IPs at the network edge before they can reach internal systems • DNS Layer: Prevent resolution of malicious domains, stopping threats before TCP connections are established • Web Proxy: Filter URLs in HTTP/HTTPS traffic to block access to phishing and malware sites • Email Gateway: Block links and attachments from known malicious infrastructure • Endpoint: Local blocklists provide protection even when devices are off-network Each layer adds protection and creates multiple opportunities to stop threats. Our blocklist data can be deployed across all these layers through our flexible API and data export formats.
Blocklist Categories for Targeted Protection
Not all threats are equal, and different organizations have different risk profiles. Our categorized blocklists let you customize protection: • Malware Distribution: Essential for all organizations - blocks servers hosting malicious payloads • Phishing: Critical for organizations with user-facing services or email traffic • Command & Control (C2): Important for detecting and preventing active compromises • Cryptomining: Reduces unauthorized resource consumption and electricity costs • Tracking: Privacy-focused organizations can block surveillance infrastructure • Spam: Reduces unwanted email and network traffic Choose all categories for comprehensive protection, or select specific categories to match your security priorities and reduce noise.
📚 Related Blog Posts
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Read More →Start Using Our Blocklist API Today
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