The Critical Role of Intrusion Prevention Systems in Network Security

What is an Intrusion Prevention System (IPS)?

An Intrusion Prevention System (IPS) is a network security and threat prevention tool. Its goal is to create a proactive approach to cybersecurity, making it possible to identify potential threats and respond quickly. IPS can inspect network traffic, detect malware and prevent exploits.

IPS is used to identify malicious activity, log detected threats, report detected threats, and take precautions to prevent threats from harming users. It allows organizations to continuously monitor the network in real time.

Intrusion prevention is a threat detection method that system and security administrators can use in a secure environment—it does not offer complete protection. IPS tools are added to a system as a precaution against anomalous events. There are many ways in which suspicious activity can occur, so it’s important to have a backup plan to detect potential attacks.

Why is an Intrusion Prevention System Important to Network Security?

There are many reasons why IPS should be an integral part of an enterprise security system. Modern networks have many access points and handle large amounts of traffic, making manual monitoring and response impractical. This is especially true in the context of cloud security, where highly connected environments create an extended attack surface, which can make protected systems more vulnerable. 

Threats to enterprise security systems are growing in number and complexity, making security automation important. IPS allows organizations to respond quickly to threats without overburdening IT teams, because they operate autonomously and do not require complex configuration. IPS is an important way to prevent some of the most severe attacks facing organizational networks.

IPS technology can detect or block network security attacks such as brute force attacks, denial of service (DoS), and vulnerability exploits. An exploit is an attack that takes advantage of a specific vulnerability to compromise or subvert a system. When a vulnerability is published, an attacker often has an opportunity to exploit the vulnerability before a security patch is applied. In this case, an intrusion prevention system can be used to immediately block these attacks.

Because IPS technology monitors packet flow, it can also be used to enforce the use of secure protocols, and deny the use of insecure protocols such as older versions of SSL or protocols with weak ciphers.

How Intrusion Prevention Works

IPS technology has evolved from intrusion detection systems (IDS)—passive systems that scan traffic and report on threats. Unlike IDS technology, IPS is located directly in the network traffic flow between the destination and source. IPS solutions usually sit behind a firewall and actively analyze and automatically respond to traffic flows entering the network. 

Here are common actions IPS solutions can perform automatically:

• Send notifications to the cybersecurity team
• Drop a malicious packet
• Block traffic from a source address
• Reset a connection
• Configure firewalls to block future attacks

IPS is an inline security component that must work efficiently to avoid degrading network performance. It has to work fast to keep up with near-real-time exploits and detect and respond accurately to eliminate false positives and threats.

In the context of notifications, IPS tools lack the ability to manage them and elevate in front of the right on-call security team/staff member. To address this limitation, organizations must consider integrating IPS tools with cutting edge alert management systems. These systems allow critical notifications to surface as high-priority, audible alerts on phone applications, reliably delivering them based on routing rules, on-call schedules and pre-established policies.   

IPS Capabilities

IPS systems can use various techniques to find exploits and protect the network from unauthorized access. Here are common capabilities:

Signature-based detection 

This detection technique relies on a dictionary of uniquely identifiable patterns (signatures) in each exploit’s code. Once an exploit is discovered, the dictionary records and stores its signature. Here are the two main types of IPS:

• Exploit-facing signatures—identify each exploit according to the unique patterns of each exploit attempt. An IPS analyzes the traffic stream for a match with an exploit-facing signature to detect specific exploits.
• Vulnerability-facing signatures—these broader signatures target an underlying vulnerability in the targeted system. These signatures help protect networks from variants of an exploit that might not have been observed.

Anomaly-based detection

This technique involves taking random samples of network traffic and comparing them to a baseline performance level. If the sample falls outside the baseline performance, the IPS handles the situation according to pre-established actions.

Policy-based detection 

This capability enables system administrators to configure security policies according to the organization’s security policies and network infrastructure. The IPS monitors the network and triggers a notification to notify admins when detecting activities that violate a security policy. 

IDPS for Alerting and Incident Response

Incident response is an organized approach to addressing and managing the aftermath of a security breach or cyberattack. Rather than being an IT-centric process, it is an overall business function that helps ensure an organization can make quick decisions with reliable information.

An Intrusion Detection and Prevention System (IDPS) prevents potential attacks by monitoring the network and alerting administrators to potential threats.

IDPS provides several actions that can be used when responding to a security incident: 

• Generating notifications for security teams
• Automatically changing system access controls or logging activity
• Logging the raw network data that caused the alert to facilitate investigation
• Terminating the session when malicious activity is detected

When properly managed, security teams can use different rules to group tasks into different categories—related to attack severity, rule reliability, target importance, timeliness of required response, and other organizational concerns. Hierarchical notifications allow operators to prioritize response and recovery actions.

For notifications categorized high up in the priority level, requiring immediate attention, simple notifications won’t make the cut. Since simple notifications run the risk of going unnoticed, modern organizations may further integrate IPS to alert management systems that elevate notifications as loud, audible, alert-until-read alerts to accelerate response. These alerts override the silent switch on phones and deliver to teams/personnel based on on-call schedules and pre-defined rules. 

Conclusion

In this article, we explained the basics of IPS and how it can enhance network security:

• Signature-based detection—This detection technique relies on a dictionary of uniquely identifiable patterns in each exploit’s code.
• Anomaly-based detection—This technique involves taking random samples of network traffic and comparing them to a baseline performance level.
• Policy-based detection—The IPS monitors the network and triggers an alert to notify admins when detecting activities that violate a security policy.

We hope this will be useful as you use an IPS system for network security and monitoring.