Comprehensive Guide to SIEM (Security Information & Event Management)

Matt Crape

7 months ago

Security Information & Event Management (SIEM) systems are an essential part of any modern cybersecurity toolbox that helps the SOC collect, detect, investigate and respond to internal and external cyber threats. This critical tool helps cybersecurity teams collect, analyze and perform security operations while maintaining and ensuring rapid, optimal incident response. We cover a lot of cloud security glossary, but SIEM is a complex topic worthy of its own page. Read on to learn more about the components of SIEM, best practices, use cases and trends.

Introduction to SIEM

SIEM is a tool that collects, aggregates and analyzes information from other cybersecurity-related systems. In the early days of the internet, SIEM tools weren’t required because there were relatively few internet-facing systems. A simple firewall to block unauthorized connections was sufficient to protect whatever systems did need to be online. It was usually safe to assume that authorized users would be connecting from inside the organization, while any attempts to access company resources remotely were unauthorized.

However, as people and businesses have evolved into a digital-dependent environment, it’s become more complex for cybersecurity teams to monitor and protect from internal and external threats. Coupled with the expansion across the digital ecosystem, a skills shortage in the cybersecurity industry and with the attack surface area of threat actors increasing, it is more important than ever to provide cybersecurity teams with the tools and resources to quickly and effectively address these threats. An organization may have multiple servers accepting connections on a variety of different ports, from file servers and databases to video chat, VPNs and more. As more data is stored digitally, organizations must worry about threats from both inside and outside the organization.

SIEM evolved as a way of monitoring and managing the sheer volume of information IT teams have to deal with on a daily basis. From threat detection to forensics and incident response, SIEM makes dealing with cybersecurity threats a much simpler task.

Components of SIEM

SIEM offers a way to collect, process and analyze information about security-related events and incidents. There are many components that go into an SIEM system, but they can be divided into two broad categories:

Security Information Management (SIM)
Security Event Management (SEM)

SIM refers to the collection of log files and other data in a central repository so that it can be analyzed at a later date. It could be more unglamorously referred to as log management. In contrast, SEM refers to the idea of processing information and monitoring events and alerts. SIEM combines the two, with data being taken from a variety of different sources, some real-time and some not, and processed to identify and better understand threats or potential issues. SIEM systems can combine data from logs, intrusion detection systems, insider threat systems and other sources and make informed decisions about which threats are significant enough to warrant alerting a system administrator for a response vs. which are more mundane activities that don’t require immediate action.

Implementing SIEM Solutions

As the threat vectors and attack surfaces increase for SOC teams to monitor and protect, businesses are fortunate for a breadth of SIEM offerings to support their cybersecurity teams. Some popular SIEM vendors are:

Splunk
Crowdstrike
Palo Alto
VMware
Microsoft
Fortinet and more

When choosing a SIEM solution, it’s important to consider your existing infrastructure. Some tools are designed with specific operating systems, servers or environments in mind. Points to consider include whether the solution is a cloud-based subscription service or an on-premises solution on your own server. Also, does your proposed SIEM work for multi-cloud, hybrid and on-premises applications?

It’s worth reading the licenses carefully. Some solutions may charge per server or charge more to add specific integrations/analytics tools, and this could become quite costly if you’re running a large/complex system.

Some SIEM solutions claim out-of-the-box support for hundreds of applications/servers from various vendors, and this can be invaluable if you want to get your SIEM solutions set up quickly. If you’re using a relatively old or obscure server and need to parse logs in an unusual format, you may find modern tools don’t support those logs out of the box. Fortunately, you should be able to manually configure parsing with most tools.

Some tools are open-source or have free tiers that may be well suited to you if you need the freedom to run the solution on a lot of servers. However, if you’re opting for a free and open-source solution, be sure to investigate the support options available. Paying for a premium support package may be worthwhile to ensure your monitoring systems are set up correctly.

Integration Strategies for SIEM

Security is a complex affair, and there’s no one-size-fits-all approach to SIEM. When you’re looking to integrate your existing security tools with your SIEM solution, start by considering your use cases and the information blindspots you have. Ask yourself the following questions:

Have you identified your SIEM objectives?
Have you created a list of needs to be addressed?
Do you have a list of your data requirements?
What data are you already logging?
Do you have a list of what you are not logging but should be logging?
How can you configure your SIEM tool to address your needs and provide better visibility into the problems you’re currently experiencing?

Many security solutions offer real-time reporting with the Simple Network Management Protocol (SNMP). They include APIs or data export systems that can help you get the data from your existing tools into your SIEM platform for analysis. When used correctly, SIEM tools can help you identify anomalies and respond to security breaches quickly and effectively.

However, if you’re logging too much or aren’t sure how to process what you’re logging, you may find yourself overwhelmed with data. It’s vital to understand what you’re looking at and have an idea of what your “baseline” is so you can spot changes in normal activity.

SIEM Use Cases

Some common examples of things SIEM deployments can pick up on include:

Compromised accounts: if a staff member is logged in at the office and then logs in 20 minutes later from 400 miles away, the account is likely compromised.
Insider threats: a system administrator or staff member with privileged credentials logging in outside of office hours, from home, could be attempting to exfiltrate data.
Brute force attempts: traditional hacking attempts such as brute force, Pass the Hash or Golden Ticket usually stand out quite clearly in logs.
Phishing attempts: SIEM could be used to determine who has received a phishing attempt and if anyone clicked on the phishing link, providing opportunities for training or taking remedial action if an account was compromised.
Remediation following a breach: if a breach does occur, even if it was not via one of the above vectors, SIEM may alert administrators to changes to a server’s configuration or even spikes in memory usage or processor usage that aren’t expected. This could alert the team that a breach has occurred, giving them time to lock down systems, diagnose the issue and take remedial action.
Malware: SIEM could be used to monitor file changes, acting as an additional line of defense against ransomware by sounding the alarm if a malware infection starts to encrypt files that are not usually accessed.

SIEM’s Role in Compliance

SIEM combines logging and analysis, helping companies protect their systems and helping them comply with privacy regulations. To clarify, SIEM is not in itself a compliance tool. However, SIEM dashboards alert administrators to threats and issues that indicate unauthorized or malicious activity. Knowledge is an essential part of cybersecurity, and SIEM arms administrators with the knowledge they need to mount a robust defense.

Some of the most common frameworks companies are required to abide by (depending on their industry) are:

HIPAA: healthcare organizations can face fines ranging from $100 to $50,000 per violation, and a single security breach could count as multiple violations.
PCI-DSS: financial organizations must comply with these regulations for secure payment and data processing. Fines can be between $5,000 and $100,000 per month.
GDPR: organizations doing business in Europe that process personal data are required to abide by GDPR, and fines can be up to 20 million euros, or 4% of the company’s turnover, whichever is greater.

There are also state or local regulations, such as California’s privacy regulations and the ICO’s data processing regulations in England. It’s up to each company to determine which regulations they’re required to abide by and to ensure they’re operating in accordance with those regulations.

SIEM can’t prevent breaches by itself; however, it can alert an organization to a breach, helping prevent further damage. It can also serve as a valuable form of due diligence. Consider the following hypothetical scenario.

Your SIEM tool alerts you to an unusual login on a long-forgotten server. Your system administrators investigate that login, discover it’s a breach and fix it while verifying that the attackers did not gain access to any sensitive data, saving you from some significant fines and poor PR. Without the early warning from the SIEM tool, the hackers may have had weeks or months to explore the compromised systems, potentially finding other vulnerabilities and being able to do some real damage by accessing privileged data.

SIEM Best Practices

To get the most out of your SIEM, it is vital to customize your implementation to your unique requirements. This includes determining what you will be logging and how you will convert that data into a format suitable for your dashboard to read. Also, consider how to automate systems to avoid overwhelming your SOC team. Here are some useful best practices to consider:

Clearly define your objectives.
Have a centralized data store for your logs and a streamlined system for consolidating that data.
Ensure you’re logging the data you need from all your security-related tools and applications.
Clearly define your log-retention policies so you have data that goes back far enough to identify patterns.
Confirm your logging and auditing is sufficient for any regulations you’re required to abide by.
Wherever possible, automate your workflows to save staff time and reduce margins for error.
Take advantage of APIs or other integrations to streamline connecting your SIEM tools to your security infrastructure.
Brief all relevant staff members on your incident response systems.
Re-evaluate your security systems and policies regularly.

For SIEM to work well, it needs to be monitoring the right things, and the quality of data going through it needs to be high. If your SIEM system is regularly throwing up false alerts, your security teams may start ignoring it. The goal of SIEM is to filter through the noise and save time for your SOC team. It may take some time to fine-tune the system, but this time investment will be worthwhile in the long run.

Evolution and Future Trends in SIEM

SIEM is evolving just as other parts of the IT ecosystem are evolving. AI and machine learning tools are helping improve SIEM solutions, particularly from the perspective of automated and rapid threat detection. As more organizations migrate to the cloud, modern security tools need to be able to work efficiently in hybrid and multi-cloud environments.

In addition, as processors get faster and storage becomes cheaper, it’s easier to process large volumes of data. Cloud data lakes and sophisticated reporting tools capable of analyzing large volumes of unstructured data make it possible for SIEM tools to analyze data that might previously have been thrown away as “too noisy.” Now, those large volumes of data can be used to better profile users and identify suspicious usage patterns, making it easier to identify compromised accounts.

Administrators can use role-based access controls and user profiles to limit the damage a compromised user account could do. SIEM tools can be used alongside firewalls, intrusion detection, endpoint security and insider threat monitoring tools to provide an all-around security solution. This kind of power and flexibility is essential in environments where remote/hybrid working is commonplace or bring-your-own-device (BYOD) policies are in place.

Unleash the Potential of SIEM

SIEM is a powerful concept for monitoring, evaluating and analyzing security threats. Next-generation SIEM tools leveraging deep learning techniques improve security by automatically detecting and identifying abnormal network behavior. Using interactive dashboards, these tools provide real-time information on malicious activities allowing administrators to take prompt corrective action.

SIEM is a key tool in your arsenal to detect and eliminate attempts by cyber criminals to compromise your systems.

While SIEM is an essential part of a proactive defense against cyber threats, it is equally important to have a fallback should a cyberattack succeed. To avoid becoming a victim, you should ensure you keep and maintain immutable backups that are safe and secure.

If you’d like to know more about how Veeam can help you with your data protection, contact us today to book a consultation or arrange a demonstration of our software.  