What is SIEM?

When It Comes to Cybersecurity – There is No Such Thing As An Unfair Advantage

Cyber-criminals are tilting the playing field to their advantage. They no longer use just their keyboards.

They are relying on AI, machine learning, and automation to conduct attacks. The dark web has become a shopping mall for malware, exploitation kits, and cyber-attack services. Any bad actor with enough cryptocurrency can become a cybercriminal.

There is Nothing Fair About Cybercrime

IT professionals responsible for cyber-security have a difficult challenge. As the value of their sensitive data increases, so does the determination of cybercriminals to make it their own. The situation is compounded with an ever-expanding attack surface caused by a rise in remote users and cloud applications.

Cybercriminals have elevated the bar leaving many organizations with new vulnerabilities. The old methods of manually managing security can’t keep pace with an army of automated bad actors intent on doing harm.

IT professionals need to tilt the cybersecurity playing field back into their favor. They need cloud-based cybersecurity, global-scale resources, autonomous threat response, and AI-driven threat detection and prioritization.

The answer to fighting these new cyberthreats is Security Information and Event Management, or SIEM. What is SIEM? Read on to find out.

What is SIEM? Understanding SIEM, SOAR, and SOC-as-a-Service

To regain their advantage, IT professionals are turning to new technologies and services. There are three new age technologies that are taking the front lines against cybercrime: SIEM, SOAR, and SOC-as-a-Service.

SIEM is the backbone of the cyberthreat data analytics tools. SOAR helps SIEM automate many processes and further investigate different cyberthreats. SOC-as-a-Service brings in a group of experts to help respond to the larger, more pressing cyberthreats detected by the SIEM and SOAR systems, creating a holistic cybersecurity system that can withstand the new, more sophisticated threats faced today.


What is SIEM (Security Information and Event Management)? SIEM is a service that collects, analyzes, correlates, and normalizes large amounts of threat data. What was once a tedious and manual process is now performed by the SIEM service. The final results are presented to IT professionals for review and action.

Basic SIEM functions include:

  • Data aggregation: SIEM services gather immense amounts of security logs, audits, control consoles, alerts, and other threat information, in real-time. The security data is collected from a variety of sources such as applications, network appliances, security sensors, firewalls, secure gateways, CASBs, endpoints, and more.
  • Correlation: The threat data is ingested by the SIEM service and analyzed to identify common attributes such as time, device ID, owner, location, and activity. SIEM services correlate security data to create a more complete and meaningful threat assessment.
  • Forensic Analysis: SIEM provides users with search criteria and inspection engines to parse through current and historical data sets. Data from various SIEM nodes can be retrieved and compiled into meaningful and actionable results.
  • Alerting: Correlated data that matches or resembles known threats or does not conform to the definition of ‘normal behavior’ will cause an alert to be sent to IT professionals.

Other SIEM capabilities are,

  • Dashboards: To improve visibility, SIEM supports tools to develop and display patterns to help identify and track threats and other abnormalities.
  • Compliance: SIEM provides special data gathering and alerting to support data governance, compliance management, and audits for PCI, HIPAA, and others.
  • Retention: SIEM data can be stored and maintained for a long period. This is important for tracing the origin of an attack back to the root cause. Data retention is required for complying with legal hold mandates and supporting compliance requirements and audits. It is also helpful to have historical reference data when developing defense, containment, and remediation plans for current and future threats.

SIEM as a Cloud-based Service

What is SIEM as a cloud-based service? A cloud-based SIEM service collects threat data on a cloud-scale from all its users worldwide. As an example, cloud-based Microsoft Azure Sentinel has a cloud-based SIEM service that collects more than seven petabytes and a million signals per day from hundreds of companies.

Although you are an individual customer, your threat data is compared to that of hundreds of other customers, many of which are service providers with customers of their own. The advantage of having such a large pool of data is that existing and new threats are analyzed and identified accurately and quickly. This leads to IT professionals having a more comprehensive security posture and remediating attacks earlier in the kill chain.

The SIEM also incorporates information on the effectiveness of its process and rolls that information back into its machine-learning engine for continued improvement of the process and accuracy in threat identification and classification.

To summarize, SIEM services collect threat data from thousands of sources. They use real-time machine learning and AI to normalize, analyze, correlate, enrich, and categorize the data. The data output is compared to existing threat profiles and other parameters. An alert is created if the process identifies a possible threat. It would take an army of cybersecurity experts to manually perform the same tasks of a SIEM service.


It is nearly impossible for cybersecurity teams to parse through, inspect, and prioritize all threat alerts generated by the SIEM service. SOAR is a supplementary cybersecurity tool to SIEM systems.

What is a SOAR (Security Orchestration, Automation, and Response)? SOAR services collect alert information from the SIEM service and other sources to further identify threats. Mundane and low-level security issues are autonomously remediated by the SOAR using predefined playbooks. More advanced incidents can be configured for a ‘click-by-click’ review by a security expert or be remediated using a third-party application. More severe, complex, and unique security threats are enriched with additional contextual information and forwarded to the security team at the SOC (Security Operations Center) for further attention. SIEM and SOAR services generally work as a team. As an example, Microsoft Azure Sentinel is a cloud-based service that offers integrated SIEM and SOAR.

It’s important to remember that SIEM and SOAR services are not the only sources of threat alerts. Alerts from other sources such as cloud applications or remote sites may not be part of the SEIM. SIEMs and SOARS do not replace the security team, only offload certain tasks. SIEMs and SOARs are tools that automate the majority of routine cybersecurity tasks, which allows the staff at the SOC (Security Operations Center) to focus on more severe incidents.


What is SOC-as-a-Service? Never forget that there is an army of experienced cybercriminals using advanced tools such as AI to create sophisticated, multi-stage attacks aimed at your security safeguards. While SIEM and SOAR services are valuable, there is no replacement for human intelligence and experience.

Complex and critical attacks require immediate and holistic attention across the entire enterprise, far beyond the reach of a SOAR. Experienced engineers intuitively know how to navigate beyond the ‘day-to-day’ processes used to find and remediate attacks quickly. They have the agility, experience, instincts, and unique toolkit needed to hunt and bring severe attacks to ground no matter where they are hiding. This is something a SIEM/SOAR or beginner engineer can’t do. In times of emergency, it’s critical to have an experienced SOC staffed with experienced engineers.

Having a SOC staffed 24 x 7 x 365 by level 3 engineers means playbooks are more numerous, efficient, and maintained. Attacks are contained and brought to ground more quickly. With experience and advanced tools, level 3 engineers know how to prioritize and manage a large number of high and critical level attacks in a shorter period of time. While beginner engineers are busy ‘learning,’— experienced engineers are stopping cyber-attacks early in the kill chain. They are more likely to close security cases in minutes or hours instead of days or weeks.

Why Is Siem Important?

Implementing a SIEM system into a cybersecurity solution provides many benefits. One is that SIEM provides customizable dashboards that make it easier to have complete visibility of your network environment in real-time. Another is that having a system that reports and logs each threat, while accessing previously known threats, helps reduce the false positive rate as the system’s AI is able to better manage threats. It also helps reduce the mean time to detect and respond to each threat since the heavy lifting is done by the system, and only needs expert attention for the most complex threats.

What’s the Difference? SIEM, SIM, and SEM

Although SIEM, SIM, and SEM are all very similar, each has different specific functions. Security Information Management, or SIM is a cybersecurity tool that reports and analyzes historic cyberthreats, meaning threats of the past. Security Event Management, unlike SIM, does not focus on historic data, but instead tries to log and report threats in real-time. SIEM, or Security Information and Event Management, is a solution that combines the knowledge of historic data (SIM) with the benefits of dealing with cyberthreats in real-time (SEM) to effectively detect, report, and respond to cyber threats.

Consider an MDR Service – The best of SIEM, SOAR, and SOC-as-a-Service all in one

Implementing and monitoring a SIEM, managing a SOAR, and operating a 24 x 7 SOC staffed with cybersecurity experts is expensive and complex. Many organizations have opted to use a professional cybersecurity provider instead of implementing a DIY ‘do it yourself’ plan. They rely on an MDR (Managed Detection and Response) provider for world-class cybersecurity. As a bonus, MDR customers have also experienced on average 50% reduction in cybersecurity costs.

A professional MDR service encompasses nearly all the processes, technologies, and techniques used to deter, detect, contain, and remediate cybersecurity threats and attacks. This includes remote users, cloud applications, compute clouds, WANs, and remote sites. MDR combines all the benefits of SIEM, SOAR, and SOC-as-a-Service to the degree a customer wants.

  • More advanced MDR service providers not only instruct the user on how to contain and remediate cyber-attacks but also if allowed behind the firewall, will help bring attacks to ground.
  • Leading MDR providers can also replace or augment the traditional SOC (Security Operation Center) with SOC-as-a-Service.
  • The customer can be involved in cybersecurity issues to whatever level they require, minimal to very hands-on.

Ontinue Delivers Cybersecurity Advantages To IT Professionals

Please contact our customer advocates to learn more about our SIEM/SOAR and SOC-as-a-Service offering. Learn more about a complete cybersecurity posture with the Ontinue ION MXDR service.