The term “intrusion prevention” refers to security mechanisms and systems that detect and automatically block or limit attacks on IT systems, applications, and networks in real time. In contrast to pure “intrusion detection” (IDS), “intrusion prevention” (IPS) reacts actively by stopping suspicious traffic, terminating connections, or shielding affected systems. Intrusion prevention functions are often integrated into next-generation firewalls, endpoint security solutions, web application firewalls, or cloud security platforms.
Real-time attack detection and blocking: Identifying attack patterns (e.g., malware, exploits, port scans) and automatically blocking the corresponding traffic.
Signature- and behavior-based analysis: Using known attack signatures as well as heuristics and behavior analytics to detect both known and new (zero-day) attacks.
Deep packet inspection: Analyzing the content and headers of network packets at protocol level (e.g., HTTP, DNS, SMTP) to identify malicious or unusual patterns.
Anomaly detection: Building “normal profiles” (baselines) for systems and networks and detecting deviations, such as unusual data volumes, unexpected protocols, or connections.
Exploit and vulnerability shielding (virtual patching): Protecting vulnerable systems through rules that block known attack techniques against unpatched software, without requiring an immediate software patch.
Policy-based access control: Defining and enforcing rules that determine which services, ports, protocols, or applications are allowed or blocked.
Automated responses: Actions such as terminating connections, blocking IP addresses, disabling or locking user accounts, or automatically quarantining endpoints.
Threat intelligence integration: Using external and internal threat data (e.g., indicators of compromise) to detect and stop new attack campaigns more quickly.
Logging, alerting, and reporting: Detailed recording of security-relevant events, real-time alerts for administrators, and reports for audits and compliance requirements.
Integration with SIEM and SOC systems: Forwarding event data to security information and event management (SIEM) solutions and security operations centers (SOC) for centralized analysis and correlation.
A financial services provider deploys a network IPS in front of its online banking platform that automatically blocks SQL injection and cross-site scripting attacks.
A manufacturing company protects its OT and SCADA networks with an intrusion prevention solution that blocks unauthorized protocols and suspicious remote access.
A mid-sized company uses an endpoint security suite with intrusion prevention capabilities to block suspicious processes and memory access on client systems.
A cloud service provider uses the intrusion prevention functions of its next-generation firewalls to prevent lateral movement of attackers between tenant environments.
A SaaS provider applies intrusion prevention rules to detect and limit brute-force and credential stuffing attacks on user accounts through lockout and rate-limiting mechanisms.