SIEM for SMBs: Do You Actually Need One?

Every few weeks, a vendor tries to sell me SIEM for my small business clients. The pitch is compelling: centralised visibility, threat detection, compliance reporting.

The reality is more complicated. Let me break down when SIEM makes sense and when it doesn’t.

What SIEM Actually Does

Security Information and Event Management (SIEM) systems:

Collect logs: Pull security-relevant data from across your environment - servers, endpoints, firewalls, cloud services, applications.

Normalise and store: Convert different log formats into a common structure. Store them for analysis and compliance.

Correlate events: Connect related events across systems. A login failure on the firewall + a successful login from a new location + unusual file access = potential compromise.

Alert on threats: Use rules and (increasingly) AI to identify suspicious patterns and alert security staff.

Enable investigation: When something happens, search across all data to understand the scope.

Support compliance: Generate reports showing log retention, security events, and response activities.

That’s the theory. The practice is messier.

Why Traditional SIEM Doesn’t Work for SMBs

Cost: Enterprise SIEMs cost tens of thousands of dollars per year. More for larger environments. The tools designed for Fortune 500 security teams aren’t priced for 50-person companies.

Complexity: SIEM deployment isn’t plug-and-play. You need to:

  • Integrate with every data source
  • Tune detection rules to reduce false positives
  • Build playbooks for alert handling
  • Maintain and update continually

Staffing: SIEM generates alerts. Someone needs to investigate those alerts. Enterprise SIEM assumes you have a Security Operations Centre (SOC) with dedicated analysts. SMBs don’t.

Alert fatigue: A poorly tuned SIEM generates thousands of alerts. Staff learn to ignore them. When a real attack happens, the alert is lost in the noise.

I’ve seen businesses spend $50,000 on SIEM and end up with an expensive log storage system that nobody actually monitors.

When You Might Actually Need SIEM

Regulatory requirements: Some industries mandate centralised logging and monitoring. Financial services, healthcare, critical infrastructure.

Contract obligations: Larger clients may require you to demonstrate security monitoring capabilities.

Incident response: If you’ve had breaches, having logs available for investigation becomes more valuable.

Growth trajectory: If you’re heading toward 100+ employees, building SIEM capability now makes sense.

Security maturity: If you’ve implemented Essential Eight controls and want to level up, SIEM is a logical next step.

For most SMBs with fewer than 50 employees, traditional SIEM is probably not the right investment yet.

SMB-Friendly Alternatives

The security market has recognised that SMBs need visibility without enterprise complexity. Some options:

Managed Detection and Response (MDR):

Outsourced security monitoring. You send logs to a service provider who monitors them with their SIEM and their analysts.

Examples: Huntress, Arctic Wolf, Expel, CrowdStrike Falcon Complete

Benefits:

  • Expert analysts monitoring your environment
  • 24/7 coverage without hiring staff
  • Incident response support included
  • Typically more affordable than building your own capability

This is my top recommendation for SMBs wanting SIEM-like capabilities.

Simplified SIEM platforms:

SIEM designed specifically for smaller organisations.

Examples: Blumira, Microsoft Sentinel (with proper configuration), Elastic SIEM

Benefits:

  • Lower cost than enterprise SIEM
  • Simpler deployment
  • Built-in playbooks and automated responses
  • Less tuning required

XDR (Extended Detection and Response):

Evolved from EDR, XDR combines endpoint, network, and cloud telemetry with detection and response.

Examples: CrowdStrike Falcon, Microsoft Defender XDR, Palo Alto Cortex XDR

Benefits:

  • Single vendor, integrated platform
  • Often easier to deploy than SIEM
  • Combines detection and response in one tool

The Microsoft Path

If you’re already in Microsoft 365, you have options within the ecosystem:

Microsoft Defender for Business: Included in M365 Business Premium. Endpoint detection with some cross-product correlation.

  • Cost: Included
  • Limitation: Limited to Microsoft ecosystem

Microsoft Sentinel: Full cloud SIEM, pay-per-use pricing.

  • Cost: Variable based on data volume
  • Benefit: Native integration with M365 and Azure
  • Challenge: Can get expensive with high log volumes

Microsoft Defender XDR: Unified detection across M365, Azure, and endpoints.

  • Cost: Included with higher Microsoft licensing tiers
  • Benefit: If you’re Microsoft-heavy, this covers a lot

For SMBs deep in Microsoft, exploring these options before buying third-party tools makes sense.

What to Do Instead of SIEM

If full SIEM isn’t right for you yet, focus on these alternatives:

1. Enable logging everywhere

Make sure logs are being generated, even if you’re not aggregating them centrally:

  • Microsoft 365 audit logs (enabled by default)
  • Endpoint protection logs
  • Firewall logs
  • Cloud platform logs (AWS CloudTrail, Azure Activity Logs, Google Cloud Audit)

When an incident happens, these logs will be essential for investigation.

2. Implement basic alerting

Most tools can send alerts for specific events:

  • Failed login attempts (Microsoft 365 can alert on this)
  • New admin accounts created
  • Disabled security tools
  • Unusual sign-in locations

You don’t need SIEM for basic alerting.

3. Use your endpoint protection

Modern EDR tools (CrowdStrike, Microsoft Defender, SentinelOne) do significant detection and correlation. They’re not full SIEM, but they cover a lot of threat detection use cases.

4. Consider managed services

AI consultants Sydney and similar firms can help design monitoring approaches that make sense for your size and budget. Sometimes the answer is managed services rather than buying tools.

Log Retention for Compliance

Even without SIEM, you need log retention. Most compliance frameworks and cyber insurers require:

  • 90 days minimum retention (some want longer)
  • Logs stored securely (tamper-evident)
  • Ability to search and retrieve when needed

Options for retention:

  • Cloud platform built-in retention (check your plan - some have limits)
  • Log forwarding to cloud storage (AWS S3, Azure Blob, Google Cloud Storage)
  • Managed backup of log data

This is different from active monitoring. You’re keeping logs in case you need them, not actively watching them.

Making the Decision

Consider SIEM / MDR if:

  • You have regulatory requirements for monitoring
  • Client contracts mandate security visibility
  • You’ve experienced security incidents and need better detection
  • You’re growing toward 100+ employees
  • You have budget for ongoing monitoring (not just tool purchase)

Stick with alternatives if:

  • You’re under 50 employees with limited security budget
  • You haven’t fully implemented Essential Eight yet
  • You don’t have staff or a provider who will actually monitor alerts
  • Your industry doesn’t mandate centralised monitoring

The honest truth: A SIEM that nobody monitors is worse than no SIEM at all. It creates a false sense of security and documented evidence of ignored alerts.

If You Move Forward

Should you decide SIEM or MDR makes sense:

Start small: Don’t try to ingest every log from day one. Start with the most critical sources:

  • Authentication logs
  • Endpoint protection alerts
  • Email security events
  • Firewall logs

Focus on signal, not volume: More logs isn’t necessarily better. Logs that generate actionable alerts are what matter.

Define response processes: Before deployment, decide who will handle alerts and how. An alert without a response process is just noise.

Set realistic expectations: SIEM doesn’t prevent attacks. It helps detect them faster. You still need preventive controls.

Budget for ongoing costs: SIEM isn’t set-and-forget. Log storage grows. Rules need tuning. Someone needs to pay attention.

Working with Specialists

This is an area where working with AI consultants Melbourne or similar firms can save significant money and frustration. They can:

  • Assess whether SIEM makes sense for your situation
  • Recommend the right approach (build vs managed services)
  • Design and implement if you proceed
  • Provide ongoing monitoring and response

For most SMBs, managed detection and response through a specialist provider delivers better outcomes than trying to build and operate SIEM internally.

My Recommendation

For Australian SMBs with fewer than 50 employees:

  1. Enable logging across your critical systems
  2. Configure basic alerting for obvious bad events
  3. Use EDR for endpoint detection (you probably already have this)
  4. Consider MDR when you have budget and need better visibility
  5. Skip enterprise SIEM unless you have specific requirements

Get the fundamentals right first. The Essential Eight doesn’t require SIEM. It requires patching, MFA, backups, and access controls.

Once those are solid, consider levelling up your detection capabilities. Until then, focus resources where they’ll have the most impact.

Final Thought

SIEM is a tool. It’s not a security strategy.

The best-protected SMBs I work with aren’t necessarily the ones with the fanciest monitoring. They’re the ones who’ve implemented fundamentals consistently and built a culture where security matters.

If you’re weighing SIEM investment against strengthening fundamentals, strengthen fundamentals first.

Detection matters. Prevention matters more.