Intrusion prevention systems (IPS) comprise one element in a comprehensive cybersecurity portfolio, proactively neutralizing cyberthreats before they enter your network and infrastructure. Due to its importance, your business must make a concerted effort to identify and implement an effective IPS. As such, it’s critical to understand the different components, types, and capabilities of an intrusion detection and prevention system.
Implementing an Intrusion Prevention System
Most organizations that store sensitive data or must comply with industry regulations would benefit from increased IT security. Intrusion detection and prevention systems improve security measures by incorporating cyberthreat intelligence to recognize regular and irregular patterns when monitoring for attacks.
This makes choosing your intrusion prevention system difficult; the right IPS depends on your business’s needs and environment. Understanding how an IPS might operate within your network will help.
What are Intrusion Detection and Prevention Systems?
Intrusion protection systems are defined as “software that has all the capabilities of an intrusion detection system and can also attempt to stop possible incidents.” Intrusion detection focuses on identifying threats and notifying relevant parties, while an IPS actually addresses incoming cybersecurity threats. Also known as intrusion detection and prevention systems (IDPS), contemporary software typically combines these capabilities.
Types of Intrusion Detection and Prevention Systems
There are four broad categories that an IDPS may be sorted into:
- Network-based – Monitors network traffic for cyberthreat indications found in particular network segments, devices, and application protocol activity.
- Wireless – Monitors wireless network activity for suspicious activity found in networking protocols.
- Network behavior analysis (NBA) – Monitors network traffic for unusual traffic flows that signify certain cyberattacks.
- Host-based – Monitors a single host for any suspicious activity that may indicate cyberthreats.
Cybersecurity Monitoring with Intrusion Prevention Systems
IDPSs leverage pattern recognition to catch cybercriminal activity. An IDPS monitors for irregular events and the known methods employed to breach security perimeters (e.g., firewalls). The system typically provides an organization with the following monitoring capabilities:
- Information and activity logging regarding observed events
- Notifications sent to administrators regarding observed events
- Reports regarding observed events
The incident and activity logs compiled by an IDPS help improve your organization’s internal cyberthreat intelligence by providing data that identifies vulnerabilities and better prepares your security team.
Intrusion Prevention Systems’ Detection Methodologies
There are typically three detection methodologies that an IDPS might utilize. More sophisticated methods require expertise in profiling and may place a significant, ongoing demand on your cybersecurity team. Profiling normal activity and its baseline patterns often requires a Managed Security Services Provider’s (MSSP) assistance to implement and configure the IDPS properly.
The three typical detection methodologies used by intrusion detection and prevention systems are:
- Signature-based detection – This method relies upon detecting known and consistent cyberthreat patterns. It’s considered the most rudimentary methodology because it depends upon a static list for comparison and is restricted to evaluating one activity at a time. The “signature” refers to the specific pattern for which a given cyberthreat is known. NIST Special Publication 800-94 provides three signature examples:
- Telnet attempts with the username “root,” as it violates organizations’ security policy
- Email subjects and attachment file names with known malware characteristics
- A “645” status code value associated with an operating system log entry (i.e., disabled auditing capabilities)
- Anomaly-based detection – This method relies on recognizing normal activity patterns to detect abnormalities that may indicate cyberthreats. Every entity in your network demonstrates a normal pattern that may be profiled. Anomaly detection allows the IDPS to anticipate unknown or internal cyberthreats better—although this may lead to legitimate activity becoming falsely identified as malware more frequently.
- Stateful protocol analysis – This method relies on recognizing benign protocol activity in every state and comparing observed events. Preset profiles provide the IDPS with a reference for benign protocol activity and are usually vendor-supplied. Stateful protocol analysis often evaluates requests and responses as well as command strings to identify cyberthreats. If actions occur outside their proper order, it may indicate a cyberthreat.
Cybersecurity Threat Response with Intrusion Prevention Systems
Once an intrusion detection and prevention system discovers a threat or incident, it will attempt to neutralize such. The advantage provided by an IDPS over previous systems is that it can take action in some form instead of merely notifying a system administrator, who would then address the threat. An IDPS will typically respond to a detected threat by:
- Stopping the attack outright – An IDPS may defend against a cyberattack by canceling the connection. An intruder requires connection, so an intrusion prevention system may attempt to defend against a cyberattack by ending it. This can be achieved by:
- Terminating the intruder’s network connection or session
- Blocking access to the intruder’s target via user account, IP address, or other attribute restrictions
- Blocking the intruder from accessing the targeted host, service, application, or another resource
- Changing the security environment – An IDPS may also change your security configuration to block access once it’s detected. For example, the security controls on network devices (e.g., router) and host-based firewalls may be adjusted by an IDPS when responding to threats.
- Changing the attack’s content – An IDPS may alter or delete malicious files and code to neutralize a cyberattack. Commands and data become benign via this method. Quarantining or removing an infected file from an email altogether is among this method’s more familiar and recognizable usages.
IDPS Implementation Considerations
Before implementing an intrusion detection and prevention system, you need to consider the following to ensure seamless interoperability and functionality that addresses your complete needs:
- The IDPS’s technical requirements and specifications (including hardware, such as dedicated servers)
- Your IT environment’s technical specifications and existing security software, policies, and procedures
- The expected and most dangerous threats for which to monitor
- Any systems, applications, or other resources that should receive higher scrutiny
- External requirements (i.e., to comply with industry regulations)
- Logging, detection, and prevention capabilities
- Performance requirements
- Resources constraints, management ease, and scalability
Tuning Your IDPS
IDPSs require adjustment to their pattern recognition’s scrutiny and detection accuracy. This process is called tuning. An IDPS relies on pattern recognition, as mentioned above. As such, the systems must have a threshold or tolerance where activity, files, and data similar enough to known cyberthreats also initiate their response. Following implementation, you need to configure an IDPS regarding how strict its detection and prevention efforts are.
When the threshold is restrictive, you will have more robust security, but more legitimate events and incidents that are falsely identified as threats will require remedy. Conversely, a less restrictive threshold will keep legitimate activity functioning without pause but may miss more cyberthreats (i.e., “false negatives”).
Tuning an IDPS is about finding a balance that works for your organization.
You want to achieve access and operational ease while maximizing protections. You should consider additional security measures that improve cyberthreat detection and response if your organization tunes your IDPS to be less restrictive.
Consult with the IDPS Experts
Implementing an intrusion detection and prevention system is a significant undertaking that requires specialized expertise. Your know-how must cover the solutions themselves, project management, configuration, and profiling. In addition, you’ll need cyberthreat intelligence and knowledge about normal network characteristics to successfully incorporate an IDPS into your IT security measures.
Contact RSI Security today to consult with cybersecurity experts who can identify your organization’s needs and assess what monitoring, detection, and prevention methodologies will work best for your IT environment, operations, and industry regulations.