IDS/IDPS

What is an Intrusion Detection System (IDS)?

An Intrusion Detection System (IDS) is a security technology designed to monitor network and system activities for malicious activities or policy violations. An IDS analyzes traffic to detect anomalies, known attack patterns, and unauthorized access attempts, providing alerts to administrators for potential security breaches.

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The types of IDS/IDPS

There are many different classifications of intrusion detection systems. The most common classifications are:

How IDS/IDPS Work

IDS and IDPS solutions utilize a combination of signature-based and anomaly-based detection techniques to analyze network traffic and system activities. Here's how they work:

1. Signature-Based Detection: IDS/IDPS systems maintain a database of known attack patterns, or signatures, which are compared to incoming network traffic or system events. If a match is found, an alert is generated, indicating a potential intrusion or security threat.
2. Anomaly-Based Detection: These systems establish a baseline of normal network and system behavior over time. Deviations from this baseline are flagged as potential anomalies. Anomaly-based detection is effective at identifying previously unknown threats or attacks that don't have known signatures.
3. Real-Time Monitoring: IDS/IDPS solutions continuously monitor network traffic, looking for patterns or activities that match known attack signatures or deviate significantly from the established norm.
4. Alerting and Reporting: When suspicious or malicious activity is detected, IDS/IDPS systems generate alerts, which can include details about the detected threat, its severity, and the affected system or network segment. These alerts are sent to security personnel or integrated with Security Information and Event Management (SIEM) systems for further analysis and response.
5. Response Mechanisms (IDPS): In addition to detection, IDPS solutions have the capability to take automated actions to block or mitigate detected threats in real-time. This proactive approach helps prevent potential security breaches.

The benefits of IDS/IDPS

Intrusion Detection Systems (IDS) and Intrusion Detection and Prevention Systems (IDPS) are essential components of an organization's cybersecurity strategy for several reasons:

1. Threat Detection: IDS/IDPS solutions play a critical role in identifying and alerting organizations to potential security threats and intrusions. By providing early warning and rapid detection, they help prevent or minimize the impact of cyberattacks.
2. Regulatory Compliance: Many industries and organizations are subject to regulatory requirements that mandate the use of IDS/IDPS to safeguard sensitive data and ensure compliance with cybersecurity standards.
3. Incident Response: IDS/IDPS solutions are integral to incident response efforts. They provide valuable information about the nature and scope of an intrusion, enabling security teams to take appropriate actions to contain and mitigate the threat.
4. Reduced Downtime and Damage: By detecting and responding to threats quickly, IDS/IDPS solutions help reduce the downtime and potential damage caused by cyberattacks, minimizing the associated costs and disruptions.
5. Network Visibility: These systems offer insights into network traffic and activities, helping organizations understand their network's behavior and identify areas of vulnerability that may need additional protection.
6. Proactive Defense (IDPS): IDPS solutions go beyond detection by actively preventing threats from compromising network security. They can automatically block or quarantine malicious traffic or suspicious activities in real-time, reducing the attack surface.

The limitations of IDS/IDPS

Attackers today can easily evade and avoid perimeter and malware detection techniques. Detection avoidance may take on one of five characteristics, or a combination of all, including:

1. Signature evasion
2. Encrypted traffic
3. Perimeter avoidance
4. Internal movement
5. Credential harvesting

Signature evasion

The most straightforward approach to evading signature-based IDPS is to use traffic that doesn’t match known signatures. This can be trivial or highly complex. For example, signature detection is often based on “known” compromised IP addresses and URLs used by botnets and malware. For attackers, avoidance is as easy as registering a new domain.

At the other end of the spectrum, highly sophisticated attackers can find and exploit previously unknown vulnerabilities. Attacks on such “unknown” vulnerabilities naturally lack the type of signature that IDPS may be attempting to locate.

Encrypted traffic

Another way to avoid signatures is to obscure the traffic. This can be as simple as encrypting malicious network traffic. While SSL decryption at the perimeter is an option, it’s costly by introducing performance penalties and has become complicated to operationalize.

Today’s sophisticated attackers use customized encryption that cannot be decrypted, even under the best of circumstances. This leaves security teams to decide whether to block or allow unknown traffic at the perimeter.

Perimeter avoidance

Attackers have learned to avoid the perimeter, and its protections altogether. By infecting users’ devices at home or outside the perimeter, threats can be carried in right through the front door.

Notably, mobile devices provide logical and physical paths around the perimeter. Mobile devices with LTE or 5G data connectivity have easy paths to the internet and act as an invisible conduit that attackers love to use to get inside networks.

Internal movement

Given the almost exclusive focus of IDPS is on the perimeter, once around the initial defenses, attackers can move much more freely. This involves an ongoing process of internal reconnaissance, lateral movement, and the access and theft of key assets. Each area employs a wide variety of attacker techniques, and they all take place inside the network where visibility is typically low.

Taking this one step further, with the onset of hybrid and multicloud deployments, network visibility gaps often extend to connections between compute and storage instances. Cyber attackers love to make use of this visibility gap.

Credential harvesting

Once inside the network, savvy attackers don’t need exploits and malware to extend their incursion. Instead, they simply harvest user credentials from compromised hosts to spread through the network. Typically, they capture a username and login during the authentication process or steal credentials or hashes from memory. In either case, attackers can spread throughout the network using valid credentials without having to use exploits or malware.

Cover IDS/IDPS security gap with Vectra AI

While IDS/IDPS solutions play a crucial role in network security, they alone may not provide comprehensive protection against advanced and evolving cyber threats. This is where Vectra AI comes in.

Vectra AI offers an advanced threat detection and response platform that goes beyond traditional IDS/IDPS capabilities.

By leveraging artificial intelligence and machine learning algorithms, Vectra AI analyzes network traffic and user behaviors in real-time, detecting sophisticated attacks that may bypass IDS/IDPS systems.

Vectra AI's ability to identify hidden threats, zero-day attacks, and insider threats fills the security gap left by IDS/IDPS solutions, enabling organizations to proactively defend their networks and respond swiftly to emerging threats. With Vectra AI, companies can enhance their overall security posture and stay one step ahead of cybercriminals.

> Read why security teams are replacing their aging IDPS with NDR

Contact us to discover how we can help you strengthen your defenses and achieve a more resilient cybersecurity posture.