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In Security Last updated: September 19, 2023
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In the current era, where data is a vital part of most businesses, security is essential for every company gathering and storing this data.

It is important because that could be the determining factor as to whether the company is successful or fails in the long term. SIEM systems are tools that could help ensure that organizations have a layer of security that helps monitor, detect, and fast-track responses to security threats.

What is SIEM?

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SIEM, pronounced as “sim,” is an acronym for Security information and event management.

Security information management is the process of gathering, monitoring, and logging data to detect and report suspicious activities on a system. SIM software/tools are automated tools that help to gather and process this information to help with early detection and security monitoring. 

Security event management is the process of identifying and monitoring security events on a system in real time for proper analysis of threats and quick action.

One could argue the similarities between SIM and SEM, but it is worth noting that although they are similar in the overall goal. SIM involves the processing and analyzing historical log analysis and reporting, while SEM involves real-time activities in gathering and analyzing logs.

SIEM is a security solution that helps businesses monitor and identify security issues and threats before they cause harm to their system. SIEM tools automate the processes involved in log collection, normalization of logs, notification, alerting, and detecting incidents and threats in a system.

Why SIEM Matters?

Cyberattack has significantly increased with more businesses and organizations moving to cloud usage. Whether you have a small business or a large organization, security is equally essential and should be handled similarly.

Ensuring that your system is secured and capable of handling a possible breach is essential to long-term success. A successful breach in data could lead to the invasion of user privacy and expose them to attack.

Security information and management system could help safeguard businesses’ data and systems by logging events occurring within the system, analyzing logs to detect any irregularity, and ensuring that the threat is handled on time before the damage is done.

SIEM can also help companies maintain compliance with regulations by ensuring their system is always up to standard.

Features of SIEM

In deciding what SIEM tool to use in your organization, it is essential to factor in some features embedded in the SIEM tool of choice to ensure all-around monitoring and detection based on your system use case. Here are some features to look out for when deciding on SIEM.

#1. Real-Time Data Collection and Log Management

Logs are the backbone of ensuring a secure system. SIEM tools depend on these logs to detect and monitor any system. Ensuring that the SIEM tool being deployed on your system can gather as much essential data from internal and external sources is key.

Event logs are gathered from different sections of a system. Hence, the tool needs to be able to manage and analyze this data effectively.

#2. User and Entity Behavior Analytics (UEBA)

Analyzing user behavior is a great way to detect security threats. With the help of the SIEM system combined with machine learning, a risk score can be given to the user based on the level of suspicious activity each user attempts during a session and used to detect anomalies in the user’s activity. UEBA can detect insider attacks, compromised accounts, privileges, and policy violations, among other threats. 

#3. Incident Management and Threat Intelligence

Any event outside normal activity can be classified as a potential threat to the security of a system and, if not handled properly, can lead to an actual incident and data breach or an attack.

SIEM tools should be able to identify a security threat and incident and carry out an action to ensure that these incidents are managed to avoid a breach in the system. Threat intelligence uses artificial intelligence and machine learning to detect irregularities and determine if it poses a threat to the system.

#4. Real-Time Notification and Alerting

Notification and alerts are essential parts/features that should be considered when selecting any SIEM tool. Ensuring that the SIEM tool can trigger real-time notifications of attacks or threats detection is vital to enable the security analysts to respond rapidly to help reduces the Mean-Time-to-Detect (MTTD) and Mean-Time-to-Respond (MTTR) hence, reducing the time a threat persists within your system.

#5. Compliance Management and Reporting

Organizations that have to ensure strict compliance with certain regulations and security mechanisms should also look out for SIEM tools to help them stay on the right side of these regulations.

SIEM tools could help businesses gather and analyze data across their system to ensure that the business is compliant with regulations. Some SIEM solutions can generate real-time compliance of business for PCI-DSS, GPDR, FISMA, ISO, and other complaint standards, making it easier to detect any violations and address them on time.

Now, explore the list of the best open-source SIEM systems.

AlienVault OSSIM

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AlienVault OSSIM is one of the oldest SIEM being managed by AT&T. AlienVault OSSIM is used for the collection, normalization, and correlation of data. AlienValut features:

  • Asset discovery
  • Vulnerability assessment
  • Intrusion detection
  • Behavioral monitoring
  • SIEM event correlation

AlienVault OSSIM ensures users have real-time information about suspected activities in their system. AlienVault OSSIM is open-sourced and free to use but also has a paid version USM which offers other additional features such as

  • Advanced threat detection 
  • Log management 
  • Centralized threat detection and incident response on cloud and on-premises infrastructure
  • Compliance reports for PCI DSS, HIPAA, NIST CSF, and more
  • It can be deployed on physical devices as well as virtual environments

USM offers three pricing packages: Essential plan, which starts at $1,075 per month; Standard plan starts at $1,695 per month; Premium at $2,595 per month. For more details on pricing, check out the AT&T pricing page.


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Wazuh is used to collect, aggregate, index, and analyze security data and help organizations detect irregularities within their system and compliance issues. Wazuh SEIM features include:

  • Security log analysis
  • Vulnerability detection 
  • Security configuration assessment
  • Regulatory compliance 
  • Alerting and notification
  • Reporting insight 

Wazuh is a combination of OSSEC, which is an open-source intrusion detection system, and Elasticssearch Logstach and Kibana (ELK stack), which has a wide range of features such as log analytics, document search, and SIEM. 

Wazuh is a lightweight version of OSSEC and uses technologies that can identify and detect compromise within a system Wazuh’s use case includes security analytics, intrusion detection, log data analysis, file integrity monitoring, vulnerability detection, configuration assessment incident response, cloud security, etc. Wazuh is open-sourced and free to use.


Sagan is a real-time log analysis and correlation engine that uses AI and ML to protect an environment with round-the-clock monitoring. Sagan was developed by quadrant information security and was built with the security operation center SOC operation in mind. Sagan is compatible with Snort or Suricata rule management software. 

Sagan features:

  • Packet analysis
  • Proprietary blue dot threat intelligence 
  • Malware destination and file extraction 
  • Domain tracking
  • Fingerprinting 
  • Custom rules and reporting
  • Breach detention
  • Cloud Security
  • Regulatory compliance

Sagan is open-source, written in C, and free to use.

Prelude OSS

Prelude smart security monitor the security by cloud information system.

Prelude OSS is used to collect, normalize, sort, aggregate, correlate, and report all security-related events. Prelude OSS is the open-sourced version of Prelude SIEM.

Prelude help in the constant monitoring of security and intrusion attempts, efficiently analyze alert for rapid responses, and identify subtle threats. Prelude SIEM in-depth detection undergoes different stages using the latest behavioral analysis or machine learning techniques. The different stages

  • Centralization
  • Detection
  • Nominalization
  • Correlation
  • Aggregation
  • Notification

Prelude OSS is free to use for test purposes. The premium version of Prelude SIEM has a price, and Prelude calculates the price based on the event volume and not a fixed price. Reach out to Prelude SIEM smart security to get a quote.


OSSEC is widely known as an open-source host intrusion detection system HIDS and is supported by various operating systems, including Linux, Windows, macOS Solaris, OpenBSD, and FreeBSD.

It features a correlation and analysis engine, real-time alerting, and an active response system, which make it classifiable as a SIEM tool. OSSEC is broken down into two main components manager, which is responsible for collecting log data, and the agent, responsible for processing and analyzing the logs.

Features of OSSEC include:

  • Log-based intrusion and detection
  • Malware detection
  • Compliance auditing
  • System inventory
  • Active response

OSSEC and OSSEC+ are free to use with limited features; Atomic OSSEC is the premium version with all features included. Pricing is subjective based on the SaaS offering.


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Snort is an open-source intrusion prevention system. It uses a series of rules to find packets that match malicious activities, sniff them out, and alert users. Snort can be installed on Windows and Linux operating systems.

Snort is a network packet sniffer hence where it got its name from. It inspects network traffic and examines each packet to find irregularities and potentially harmful payloads. Features of Snort include:

  • Real-time traffic monitoring
  • Packet logging 
  • OS fingerprinting
  • Content matching

Snort offers three pricing options personal at $29.99 per year, business at $399 per year, and integrators for anyone looking to integrate Snort into their product for commercial purposes.

Elastic Stack

The search platform that helps you search, solve and succeed.

Elastic (ELK) Stack is one of SIEM systems’ most popular open-source tools. ELK stands for Elasticsearch Logstach and Kibana, and these tools are combined to create a log analyzer and management platform.

It’s a distributed search and analytics engine that can perform lightning-fast searches and powerful analytics. Elasticsearch can be used in different use cases, such as log monitoring, infrastructure monitoring, application performance monitoring, synthetic monitoring, SIEM, and endpoint security.

Features of elastic search:

  • Security
  • Monitoring 
  • Alerting 
  • Eleasticsearch SQL
  • Anormal detection using ML

Elasticsearch offers four pricing models

  • Standard at $95 per month
  • Gold at $109 per month 
  • Platinum at $125 per month
  • Enterprise at $175 per month

You can check out the Elastic pricing page for more details on pricing and the features of each plan.

Final Words

We have covered some SIEM tools. It is essential to mention that there is not a one size fit tool when it comes to security. SIEM systems are usually a collection of these tools handling various areas and performing different functions.

Hence, an organization needs to understand its system to select the right combination of tools to set up its SIEM systems. Most of the tools mentioned here are open source, making them available to manipulate and configure to meet the demand.

Next, check out the best SIEM tools to secure your organization from cyberattacks.

  • Aminu Abdullahi
    Aminu Abdullahi is an experienced B2B technology and finance writer and award-winning public speaker. He is the co-author of the e-book, The Ultimate Creativity Playbook, and has written for various publications, including Geekflare,… read more
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