SIEM Implementation: Planning & Best Practices

SIEM systems simplify cybersecurity by aggregating logs, monitoring for threats, and alerting teams to unusual activity. This post covers what SIEMs are, their benefits, and how to implement them step-by-step.
By SentinelOne October 24, 2024

Parsing through error logs as a cybersecurity manager could be a chore. Firstly, apart from the sheer hundreds of entries to sift through, you would need to repeat the process several times in various systems, servers, OS, etc. In addition, every system may use its peculiar way of writing logs, so an analyst has to memorize a plethora of formatting styles. With that done, now it is time to look for patterns on the freshly decoded data, such as multiple failed login attempts, unusual access times, or unusual access from locations.

It can sometimes be cumbersome and very time-consuming. This is the reason why a SIEM is an invaluable tool in every organization’s security arsenal. It allows easy processing of data by collecting intelligence from a variety of sources. The benefits of real-time monitoring can be accrued, and alerts about any strange security incident are received. One can point out unusual events promptly and without hassle.

Today, we’re going to talk about the deployment of SIEM solutions. We will answer questions such as: What is a SIEM? Why is it helpful, and how do you step-by-step implement one in your organization? Let’s get started.

What Is SIEM and How Does it Work?

SIEM solutions are powerful security tools that collect and analyze otherwise disparate logs from across your network’s security systems, using them to give you timely security alerts. Without them, log analysis would become a long and laborious affair, since security managers would need to navigate each system individually, learn its format, and scour the data for hints of errors. SIEM also analyzes security-related data from various sources within an organization’s infrastructure.

Choosing the Right SIEM Solution

Choosing a SIEM solution is subjective but crucial and every enterprise has to decide.  Leading vendors like SentinelOne offer the best options in the industry. What matters is finding a solution that aligns with your unique requirements. A great starting point is to evaluate your environment and security priorities; it’s because SIEM solutions are truly diverse in feature sets.

Generating SIEM reports takes a while, which could negatively impact your incident response and detection times. Therefore, automation must be the focus while ensuring that your chosen SIEM solution natively produces reports in real time to help improve your overall security posture.

You need to factor in the scalability of a SIEM tool, especially as your organization grows. An ever-increasing volume of data is being generated on the network, so the solution’s ability to scale with the addition of new data sources and accommodate changing needs will be paramount. Transparency in how well the solution scales, perhaps through licensing based on devices or data sources, will be critical in ensuring that the solution makes room for your future requirements.

Long-term event storage and compliance are also necessary. Because logs and security event data arrive rapidly, selecting an SIEM with enough but customizable storage capabilities becomes vital. That goes a long way toward regulatory compliance and ensures only the relevant information is kept in storage.

Not last, but not least, the ease with which the solution may be deployed and implemented to meet a user’s requirements. The deployment process of an SIEM solution is often one of the most cross-departmentally dependent processes. The choice of a vendor who can provide more comprehensive documentation, user guidance, and a less complicated setup can greatly accelerate the entire process of deploying and configuring your chosen SIEM solution. That means your team will be up and running with the tool to the best of its ability to help better protect your organization.

Siem Implementation - Choosing the Right SIEM Solution | SentinelOnePreparing Your Organization for the New SIEM Solution

Implementing a new SIEM solution requires careful planning and execution, plus a thorough understanding of your organization’s special security and compliance needs. The very first step in this journey is defining your security objectives. For example, are you implementing a new SIEM solution to improve threat detection capabilities, enhance network-wide visibility, or ensure that regulatory compliance standards are met with GDPR, HIPAA, or PCI-DSS?

Well-defined goals will form the basis of the entire implementation process; every step taken should be moving in the direction of your overall strategy for your organization in security.

Before entering the implementation process, it is absolutely important to analyze the security posture of your organization today. This will involve identifying all sources of potential data, types of integrations required, and how much customization is necessary to adapt the SIEM solution to your environment. Drawing up a scope of the project with a realistic timeline and critical milestones will help in managing expectations and resources effectively. Above all, you will require a complete training program for your staff related to SIEM administration, incident-handling protocols, reporting, and troubleshooting as critical elements to successfully implement and apply the solution.

You can opt for a phased implementation or roll-out when adopting it.

SIEM Installation and Configuration

The first step to installing an SIEM solution is to download the software from the company’s website. You then need to install the SIEM. Some vendors also deliver dedicated hardware with the SIEM software pre-installed, but if your vendor does not, it is important to ensure that the hardware you are installing has the computing power to continually monitor your entire network.

If you opted for a cloud-based solution, though, you only need to set up a new instance on the cloud provider’s platform (AWS, Azure, GCP, etc.). Refer to your SIEM solution’s provider for specific steps for configuration.

Integrating Data Sources

Once installed, you should begin integrating your pre-decided data sources into the SIEM. Common data sources include network devices (such as routers), application servers and user devices, IPS and IDS systems, and cloud platforms for insights into cloud resource usage and security events. You may wish to include as many data sources as you can or only a handful of sources for monitoring specific parts of your network. Many organizations have dedicated SIEM systems for their apps and/or cloud services.

You must configure these data sources to generate and send logs to the SIEM. Different operating systems have various logging protocols which you may use to retrieve events. Windows Event log and Syslog are commonly used protocols for sending logs over a network. Many devices and applications can be configured to forward logs to the SIEM via Syslog. However, you can also install agents on endpoints that automatically send log data to the SIEM, or you could configure the SIEM to monitor specific log files on servers or applications in real-time.

If you are monitoring cloud services, traditional logging features may not be available. You may have to use native cloud logging services. But most cloud logging services generate detailed log entries that you can route to your SIEM.

SIEM Implementation - Many organizations have dedicated SIEM systems for their apps and/or cloud services | SentinelOneCustomizing and Fine-Tuning Your SIEM

With your SIEM up and running, you need to configure it to ensure it behaves as you want.

The first step of this is usually defining what normal network activity looks like and does not look like. This is best done by using previous data from the pre-established attack vectors you found during your gap analysis. With the data, you can establish what normal levels of activity and network traffic look like. You can then set up correlation rules. Correlation rules tell the SIEM that, if a certain pair or string of events occur in a certain order, then a notification should be raised.

Luminis’s blog gave a great example of this. According to them, you can set up a correlation rule to “Warn administrators if five failed login attempts are tried with different usernames from the same IP to the same machine within fifteen minutes (“x”), [and] if that event is followed by a successful login occurring from that same IP address to any machine inside the network (“y”).”

This may, of course, be a human error. But it may also be an attacker trying to brute-force their way into the system.

You can also tailor your alert mechanisms to suit your team’s specific workflows. You may consider setting up email notifications, SMS notifications, and so on.

Challenges and Best Practices in SIEM Implementation

#1. Complexity

The biggest challenge in implementing an SIEM may be its complexity. As you can see, it is not an easy process!

If you are not a cybersecurity technician, it is crucial to invest in a skilled team that can assess your network to set up correlation rules, determine which data sources to integrate, and tailor alerts to suit your team’s needs. Failure to do so could lead to missed threats or false positives, which may affect your company.

#2. Scalability

Scalability is another potential challenge that organizations must prepare for. As an organization grows, it needs an SIEM solution that can handle the increasing amounts of traffic being sent on the network. Failure to do so could lead to missed threats and/or performance issues.

Organizations should choose their SIEM with scalability in mind and ensure they pick a deployment mode that works for them.

#3. Hidden Costs

Many SIEM solutions may come with hidden costs separate from the yearly subscription fees. You should thoroughly understand your provider’s terms of service, especially when it comes to network usage and data volume.

Selecting the Right SIEM Is Crucial

Selecting an SIEM solution for your organization can be a long and daunting process. You must ensure that you assess your infrastructure properly, choose the right service for your organization, and then set it up properly to make it work effectively. However, the process does not need to be difficult at all times. Solutions like SentinelOne, with their flexible packages and top-notch support, make selecting the right solution easy.

FAQs

1. What is SIEM?

Security information and event management, or SIEM, involves collecting and analyzing security data from your network. It is crucial to cybersecurity, as SIEM systems are used to monitor activity logs to ensure your network is not under attack.

2. How do you implement SIEM?

This is a long process. The first step involves conducting a gap analysis to understand your current infrastructure. You must then decide what solution is right for you after considering the attack vectors you wish to monitor, product prices, scalability, and deployment modes.

3. What are some challenges in implementing an SIEM?

Implementing an SIEM can come with some challenges including complexity, scalability, and hidden costs. It’s important to factor these into your decision-making process as you consider adopting a SIEM solution for your organization.

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