SIEM vs. SOAR vs. XDR: Differences, Uses, and How to Choose the Best Combination

Have you seen Dawn of the Dead? Because cybersecurity professionals live it every day, surrounded by increasingly sophisticated attacks that come in endless waves. Every bit of help counts — and that’s where tools like SIEM, SOAR, or XDR, three fundamental pillars of modern security, come into play.
That’s why we’ll analyze each of them and how to choose the best combination for your specific needs. The goal is to build an impregnable Fortress of Solitude that protects your IT infrastructure.
In doing so, we’ll also clear up common confusions, especially around XDR, since overlapping features, aggressive marketing, or lack of understanding about each tool’s purpose might lead to misconceptions.

The myth that XDR may replace SIEM and/or SOAR

With XDRs landing in the modern security battlefield, it’s sometimes said that this technology alone is enough, making SIEM and SOAR obsolete.
Nothing could be further from the truth because, as we’ll see, no matter how powerful XDR is — or how much it tries to work like SIEM and SOAR — it falls short in many critical situations such as: hybrid infrastructures, compliance, audits, or coordination of heterogeneous tools.
Your IT infrastructure won’t be identical to anyone else’s in terms of requirements, regulations, or components. Those Frankenstein-like environments often demand flexibility and capabilities that XDR simply can’t always deliver.

What SIEM and SOAR still bring to a modern SOC

Later, we’ll see how a SOC benefits from the SIEM’s ability to serve as the central repository of all organizational telemetry — a single source of truth, as a friend says — essential for forensic investigations and audits.
Likewise, SOAR adds automation, enabling consistent and quick incident response, even with limited human resources.
Achieving this level of effectiveness using XDR alone would be difficult, so it’s important to understand each contender well to know which pieces we need in our specific security puzzle.

SIEM: the classic SOC pillar

A SIEM (Security Information and Event Management) tool, such as Pandora SIEM, is the platform that centralizes, normalizes, and correlates logs from multiple sources (networks, servers, applications…) to detect threats, generate alerts, and ensure compliance.
However, it doesn’t act on this data automatically; it depends on rules and human analysis.
Think of it like the Enterprise computer in Star Trek — it knows everything happening in the ship (your IT infrastructure), processes it, and provides information and alerts whenever a security event takes place or the crew needs data.
However, it’s still the crew that decides what actions to take; that computer doesn’t act on its own (except in those classic episodes where it becomes self-aware).

Key functions: logs, correlation, and compliance

The SIEM has been the backbone of the Security Operations Center (SOC) for years, performing:

• Log Aggregation and Storage: Collecting security event data from multiple sources into a central repository.
• Event Correlation: The SIEM applies rules and correlation logic to analyze logs to identify patterns that indicate malicious activity. It transforms millions of events into a manageable number of alerts — enough to stay sane and not chase white rabbits nowhere.
• Regulatory Compliance: The SIEM may generate reports demonstrating compliance with regulations like GDPR or HIPAA, thanks to its ability to retain data over long periods and audit who did what and when.

Limitations against modern threats

No analysis would be honest without mentioning the challenges each tool faces in today’s relentless cybersecurity landscape. These include:

• High data volume: Log storage can become costly, though this may be mitigated with a solid maintenance policy that respects legal obligations.
• Excessive potential alerts: Often caused more by poor configuration than by the tool itself.

Current role: why SIEM still matters in an XDR world

The SIEM remains essential in modern security infrastructures because it serves as:

• A long-term regulatory compliance repository.
• A high-level correlation platform — the brain of operations — integrating enriched XDR alerts with data that XDR can’t collect, enhancing its efficiency and mitigating its weaknesses.
• The core of an open architecture, leveraging standards like OpenID Connect (OIDC) and APIs to integrate with XDR, SOAR, and other security tools.

SOAR: response automation and orchestration of response

SOAR (Security Orchestration, Automation and Response) is the tool that automates and coordinates (orchestrates) incident response tasks using predefined playbooks.
In other words, it automatically deploys the first drones into battle to mitigate, clearing the way for human reinforcements if needed in complex incidents.
For example, in the case of a malware threat triggered by a click on an email received on a company laptop, SOAR can shut down connections, block the link’s target IP, the device and/or the user account, based on the response defined in its playbook for these cases.
SOAR aims to reduce response times (launching those automatic defenses upon detection) and ease the operational burden on the SOC human team.
Here, the analogy would be J.A.R.V.I.S. from Iron Man, or R2-D2 in a Star Wars X-Wing, assisting in battle by aiming, selecting targets and executing actions, like deploying armor or executing evasive maneuvers at silicon-brain speed.

What it brings compared to SIEM

While SIEM focuses on detection, SOAR focuses on first response. A SIEM says “something bad is happening”, a SOAR “does something about it” automatically.
SOAR does not replace SIEM, it acts upon its alerts (and those from other sources) to take action.

Key functions: playbooks and immediate response

SOAR’s power lies in its playbooks, predefined and automated workflows for handling common security incidents. Examples of use and functions in our security infrastructure would be:

• Investigation and triage without human intervention: Such as receiving a phishing alert, checking threat intelligence APIs to analyze the attached URL, and if it’s malicious, blocking it in the firewall and email.
• Endpoint containment: In case of potential ransomware, isolating the affected endpoint from the network to prevent spread.
• Team coordination: Automatically opening an incident in the ticketing tool, such as Pandora ITSM, assigning it to the appropriate team and notifying the manager via Teams.

Again we see the power of combining SIEM and SOAR: SIEM correlates and detects incidents like Sauron’s all-seeing eye, while SOAR has countermeasures ready for anything that emerges when SIEM lifts a rug and a surprise appears.
Now let’s see how XDR fits into the impenetrable security puzzle.

XDR: Extended Detection and Response

One of the main evolutions in cybersecurity is the XDR (Extended Detection and Response) concept, which addresses a key gap in EDRs.
EDR (Endpoint Detection and Response), as the name implies, focuses on monitoring and response on endpoints (computers and servers). But XDR goes further: it’s a unified platform that extends detection and response beyond the endpoint by integrating data from network, email, cloud, identities and cloud workloads (IaaS/PaaS).
Thus, it offers:

• Native integration.
• Cross-source analysis, providing a more complete and contextual view of attacks.

In this case, instead of a T-800 Terminator on each device, like EDRs, we evolve to a T-1000 — far more versatile and capable of acting not only on endpoints, but across many environments.
Here, as mentioned earlier, the lines between tools start to blur (a logical and inevitable evolution), since XDR includes aspects of both SIEM and SOAR.
So, what’s the catch? For many organizations, that “something” isn’t enough, especially in complex infrastructures or those requiring regulatory compliance.

Open XDR vs Native XDR

When talking about XDR, we usually find two types:

• Native XDR: The solution provided by a single vendor, like CrowdStrike. Here, we rely on that vendor’s implemented capabilities. The advantage is seamless integration between their own products. The risk —besides vendor lock-in and limited interoperability— is being constrained by what the vendor has implemented.
• Open XDR: These are solutions supporting integration with tools from multiple vendors via APIs or open standards. The advantage is flexibility and avoiding being locked into one vendor. The risk is potentially less deep integration, possibly leaving vulnerabilities.

The role of XDR in a modern SOC

XDR acts as a force multiplier for analysts, replacing the old EDR tank with a spaceship capable of operating in more environments, more effectively, with:

• Faster and more precise responses, no matter where the threat arises.
• Better alerts, thanks to correlated analysis similar to a SIEM.
• Faster, more accurate investigations, with richer context from multiple data sources.

As mentioned earlier, XDR tries to do it all, combining capabilities from EDR (with greater reach), SIEM and SOAR by offering detection, analysis, and response features.

RPA Examples Applied to IT Management

Now that we know the options, let’s put them face to face.

SIEM vs SOAR: Collection vs Orchestration

Feature	SIEM	SOAR
Main focus	Data collection, correlation, and storage.	Automation and orchestration of response processes.
Main output	Security alerts and compliance reports.	Automated actions, ITSM tickets, resolved cases.
Key value	Centralized historical visibility, integrated analysis of disparate sources.	Speed, scalability, and consistency in response.
Relationship	The SIEM is a key intelligence source for the SOAR.	The SOAR consumes and acts on SIEM alerts.

SIEM vs XDR: Coexistence vs Replacement

Feature	SIEM	XDR
Data scope	Broad and generic (any log).	Focused and deep (security telemetry from key sources).
Analysis	Rule-based correlation.	Contextual and behavioral analysis across domains.
Main purpose	Compliance, auditing, high-level correlation.	Proactive threat detection and response.

As we can see, XDR doesn’t replace the SIEM, which remains a broader specialist in analytics and intelligence, but it is an excellent complement when working with SIEM data.

SOAR vs XDR: Automation vs Extended Detection

Feature	SOAR	XDR
Main function	Automate response workflows.	Detect and investigate threats in a unified way.
Strength	Connects disparate tools and automates complex processes.	Provides superior detection and integrated context.
Dependency	Needs quality alerts from sources like XDR or SIEM.	Can benefit from SOAR to automate response to detections.

Here, SOAR can work alongside XDR and the information it generates to enhance automated responses.
In many infrastructures, this information may not be as broad or optimal as with a proper SIEM, but it can still be an effective solution.

Practical Examples of When to Use Each One

Security demands are becoming higher, not only due to the threat sophistication but also because of increasingly strict regulatory requirements.
Let’s look at common scenarios and the optimal tool for each.

Scenario: PCI DSS Compliance

Main tool: SIEM. Essential for collecting all logs from the CDE (Cardholder Data Environment), storing them for the required period, and generating audit reports.
Something similar applies to compliance with the European NIS2 for critical organizations. Good luck doing it without a SIEM!

Scenario: Sophisticated Phishing Campaign Detection

Main tool: XDR. For this everyday issue, it could correlate a malicious email detected in Office 365, with an outgoing connection from an endpoint and a suspicious PowerShell execution, generating an alert.
As we see, this goes beyond endpoints like in an EDR and shows how XDR delves into SIEM territory.

Scenario: Response to Ransomware

Main tool: SOAR. Upon receiving an alert from XDR, EDR, IDS, or SIEM, the SOAR executes a playbook that could include:

• Isolating the infected machine.
• Blocking the ransomware hash across all devices.
• Disabling the affected user account in Active Directory.
• Opening a ticket in Pandora ITSM.

The Security of Hybrid Architectures: The Most Realistic Scenario

We all know (and go through) that any technologically mature organization ends up building a hybrid infrastructure, trying to leverage the benefits of each environment while also being exposed to the unique vulnerabilities of each option.
That’s why the optimal security approach for such a castle has that same hybrid nature.

How SIEM, SOAR and XDR Combine in a Mature SOC

In an ideal world that we should strive to build…

• XDR acts as a highly efficient and contextualized detection and response layer, filtering noise and generating quality alerts.
• These alerts go to the SIEM for correlation with other contexts or for storage.
• They can trigger SOAR playbooks to automate an immediate response, which may include XDR closing the loop.

Thus, instead of competing, they form a security structure that protects everything from the most modern cloud to that basement server nobody knows what it does and hasn’t been turned off since ’97.
With this we achieve:

• Regulatory compliance: Where the SIEM keeps us out of a Kafkaesque legal nightmare. XDR and SOAR are not designed for such obligations.
• Multi-context detection: XDR is king. The SIEM may try to simulate this correlation with custom rules, but it’s more expensive and less effective.
• Automation at scale: This is where SOAR comes in handly — so we don’t pay an engineer’s salary just to block phishing manually.

But what if we can’t afford them all?
We must decide what suits us best, and the following checklist is a good starting point.

Decision Checklist: How to Choose Between SIEM, SOAR and XDR

Obviously, the first step is to know your IT infrastructure inside and out. From there, consider the following key questions:

• Do we have a sense of control over what’s going on? This is the starting point. If not, SIEM is essential.
• Do we need long-term log retention for compliance (NIS2, ISO27001, etc.)? Prioritize SIEM.
• Is that legislation critical (e.g. we are a strategically important organization under NIS2)? Again, SIEM is a must.
• Is our SOC overwhelmed with alerts and slow manual response? Prioritize SOAR.
• Do we have tasks that could be automated? If simple, XDR may be enough; if complex, prioritize SOAR.
• Is our infrastructure highly heterogeneous? If not, XDR may suffice; if so, we need SIEM’s flexibility as the unifying brain.

Then, of course, we will answer to the main master: money — so the cost of each solution must be considered:

• SIEM: High cost for data storage; also requires ongoing maintenance and rule tuning.
• SOAR: The main cost is the license. It also requires maintaining playbooks and possibly developing custom ones.
• XDR: Cost may be per endpoint or based on license model.

How Pandora FMS and Pandora SIEM Fit into This Ecosystem

Pandora FMS, as a unified monitoring platform, and Pandora SIEM, as a security information and event management solution, are the core of this layered defense architecture, providing:

• Total control. With a complete view of performance and data collection by Pandora FMS, which may be correlated and used by Pandora SIEM to detect attacks.
• Optimal incident management through ITSM.
• Empowerment of other solutions. Acting as a super-intelligent brain that sees what others cannot. Thanks to its superior analysis and correlation capabilities, other tools like SOAR or XDR become more effective.
• Higher ROI compared to other solutions. Thanks to its flexibility and consolidation potential, we get a unified platform, even if working with a fragmented infrastructure.

I’m afraid life and cybersecurity are too complex to fit into a single solution. The debate is no longer SIEM vs SOAR vs XDR, but rather SIEM + SOAR + XDR.
Each tool plays a role in the security lifecycle: XDR drastically improves detection and context, SIEM offers analysis, centralized storage, and compliance, while SOAR enables fast, automated response.

Frequently Asked Questions

Let’s summarize some key points and common doubts we’ve covered.

Does an XDR replace a SIEM?

Not directly, although an XDR has some features in common with a SIEM.
An XDR focuses on proactive detection and response with enriched context, whereas a SIEM is crucial for long-term log storage, multiple-source correlation, and regulatory compliance.
They often coexist and integrate, especially in heterogeneous infrastructures where XDR falls short in covering all elements.

What’s the difference between SIEM and SOAR?

Their main function. SIEM is a detection, correlation, and storage tool, but it doesn’t take action. SOAR, on the other hand, is a response and automation platform.
Again, they’re complementary. SIEM identifies potential incidents and points the finger, while SOAR deploys the automatic measures that respond to that alert.

What’s the difference between XDR and EDR?

EDR monitors and protects endpoints (like computers and servers). XDR goes further — that’s what the “Extended” in its name refers to — integrating and correlating data from endpoints, network, email, cloud… offering broader and more accurate detection.

Which solution to choose: SIEM vs SOAR vs XDR?

It’s not a mutually exclusive choice in today’s context, where threats are like a seven-headed hydra that never stops attacking.
A mature SOC or an organization with significant security requirements will end up combining all three tools, as each is specialized in a different area.
For more details, see the sections on practical examples and hybrid architecture security.

Is XDR the same as SIEM?

No. Although both correlate data, SIEM is more flexible since it can access and normalize a wide range of logs.
XDR applies advanced analytics to specific security telemetry from multiple natively integrated sources to detect complex threats. But if that integration doesn’t include, for example, the legacy server in the basement that hasn’t been shut down since ’97, XDR will have a blind spot that a SIEM could still monitor — provided it can access its logs somehow.