What are the best practices for intrusion detection policies against emerging threats?

1 Define your objectives

Before you design or update your intrusion detection policies, you need to define your objectives and goals. What are you trying to protect? What are the risks and impacts of a breach? What are the legal and regulatory requirements? What are the performance and resource constraints? By answering these questions, you can align your policies with your business needs and priorities.

2 Choose your methods

There are different methods of intrusion detection, such as signature-based, anomaly-based, or behavior-based. Each method has its advantages and disadvantages, depending on the type and complexity of the threats you face. For example, signature-based methods can detect known threats quickly and accurately, but may miss new or modified attacks. Anomaly-based methods can identify unusual or suspicious activities, but may generate false positives or negatives. Behavior-based methods can learn from historical data and adapt to evolving threats, but may require more processing power and storage. You should choose the methods that suit your objectives and resources, and combine them if necessary.

3 Configure your sensors

Once you have chosen your methods, you need to configure your sensors, which are the devices or software that monitor and collect network traffic or system events. You should place your sensors strategically, depending on whether you want to use network-based or host-based intrusion detection, or both. Network-based sensors can capture data from multiple sources and detect attacks that span across different hosts, but may not have access to encrypted or internal traffic. Host-based sensors can provide more detailed and granular data from individual hosts, but may not have a holistic view of the network. You should also tune your sensors to reduce noise and optimize performance.

4 Manage your alerts

The next step is to manage your alerts, which are the notifications or reports that inform you of potential or actual intrusions. You should define your alert criteria and thresholds, based on the severity and frequency of the events. You should also define your alert channels and formats, such as email, SMS, dashboard, or log file. You should also establish your alert response procedures, such as escalation, investigation, mitigation, or recovery. You should also review and analyze your alerts regularly, to identify trends, patterns, or gaps.

5 Update your policies

Finally, you should update your policies periodically, to ensure that they are relevant and effective against emerging threats. You should monitor and evaluate your policies, using metrics such as detection rate, false positive rate, false negative rate, or response time. You should also gather and incorporate feedback from your stakeholders, such as users, managers, or auditors. You should also research and benchmark your policies against industry standards and best practices, such as NIST, ISO, or CIS.

Intrusion detection policies are essential for network security, but they are not one-size-fits-all. By following these best practices, you can create and maintain policies that suit your needs and protect your assets against emerging threats.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?