Best File Integrity Monitoring Tools (2026): 9 Compared

When an attacker gets onto a server, one of the first things they touch is a file: a config, a binary, a startup script. If nobody's watching those files, the change can sit there for months.

File integrity monitoring is the habit of watching them. The nine tools below are listed alphabetically and in no particular order, and every description comes from the vendor's own website, read this week. If you're building a wider plan, my guide to cybersecurity essentials for customer-facing platforms covers the basics around it.

File integrity monitoring tools at a glance

I checked the free plan column on each tool's own website, as of Oct 2026. Yes means the site names a free plan, a free version, a free account, a free edition or an open source release. Trial only means a time-limited trial. Not stated means the pages I read named neither, even where there's a button inviting you to try it, so check the vendor's page before you sign up.

Tool	Type	Good for	Free plan
AIDE	Open source integrity checker	Linux and Unix file checks	Not stated
CimTrak	Integrity and compliance suite	Integrity across servers and network devices	Trial only
EventLog Analyzer	Log management with integrity checks	FIM inside log management	Yes
Netwrix Change Tracker	Change tracking and FIM	Tracking approved and unapproved change	Not stated
OSSEC	Open source HIDS	Free host intrusion detection	Yes
Qualys FIM	Cloud FIM app	Compliance-led real-time monitoring	Not stated
Rapid7	Security operations platform	FIM alongside detection and response	Not stated
Samhain	Open source HIDS	Many hosts with central logging	Yes
Wazuh	Open source XDR and SIEM	FIM in an open source security stack	Yes

Nine file integrity monitoring tools to consider

AIDE

Best for: Linux and Unix admins who want a lightweight file and directory integrity checker that builds a database and verifies files against it.

CimTrak

Best for: Security teams at small, mid-market and enterprise firms who want file integrity monitoring tied to hardening and compliance, with a free trial.

EventLog Analyzer

Best for: IT teams who want file integrity monitoring as part of a wider log management and compliance tool, with a free edition to download.

Netwrix Change Tracker

Best for: Compliance teams who want file integrity monitoring from the product formerly sold as NNT Change Tracker, now part of Netwrix.

OSSEC

Best for: Teams on a tight scope who want a free, open source host-based intrusion detection system with log analysis and file integrity monitoring built in.

Qualys FIM

Best for: Organisations already on the Qualys cloud platform who want real-time file integrity monitoring aimed at compliance from the same console.

Rapid7

Best for: Security operations teams who want file integrity monitoring explained and delivered as part of a wider detection and response platform.

Samhain

Best for: Admins running many POSIX hosts who want open source file integrity checking with centralised logging and a web-based management console.

Wazuh

Best for: Teams that want file integrity monitoring inside an open source XDR and SIEM platform, self-hosted or as a cloud service.

Which FIM tool fits which setup

• Free, self-hosted checks on Linux: AIDE or OSSEC.
• Many hosts with central logging: Samhain.
• FIM inside an open source security stack: Wazuh.
• FIM inside log management: EventLog Analyzer.
• Compliance-led change control: CimTrak or Netwrix Change Tracker.
• Teams already on a big security platform: Qualys FIM or Rapid7.

What the PCI Council says FIM has to do

The PCI Security Standards Council's glossary defines file integrity monitoring as a change-detection solution that checks for changes, additions and deletions to critical files, and notifies when such changes are detected.

Notice the last part. Spotting the change isn't enough on its own: the alert is part of the definition. If you take card payments, a tool that quietly logs changes nobody reads won't help you much, so judge every option on how it tells a human.

Baseline, watch, alert: how FIM works

First the tool takes a baseline, usually a hash of each file you care about plus attributes such as permissions and owners. That snapshot is your known good state.

Then it watches. Some tools check on a schedule, others watch in real time. Either way, every new hash is compared with the baseline.

Finally it alerts, and this is where tools differ most. The useful ones let you mark planned changes as approved, so your team only hears about the ones nobody expected.

Questions to ask before you pick one

1. Which operating systems and devices does it cover?
2. Does it check in real time or on a schedule?
3. Can it tell approved changes from surprises?
4. Will it produce reports your auditor accepts?
5. Does it send alerts where your team works?
6. Who maintains the baseline after updates?

Signs your file monitoring needs work

• Alerts go to an inbox nobody reads. Route them to the team chat.
• Every patch floods you with changes. Add approved change windows.
• The baseline is years old. Rebuild it after each major update.
• Only servers are covered. Add network devices and cloud images.

Do you make file integrity monitoring or security tools? Tool makers can ask to be considered for a featured place on this list.

My plain advice on file integrity monitoring

Start small. Pick the twenty or thirty files and settings that would hurt most if someone changed them, put them under monitoring and tune out the noise before you widen the scope. A tool that shouts about every update gets ignored by week two.

Then tie it to your change process, so a planned change is approved in advance and anything else gets a human look the same day. My guide to building a strong cybersecurity culture helps with the people side of that.

Frequently asked questions

What is file integrity monitoring?

It's a security control that compares critical files and settings against a trusted baseline and alerts you when they're added, changed or deleted.

Is there free file integrity monitoring software?

Yes. Several open source tools check file integrity at no charge, and some commercial vendors offer a free edition or a trial.

Does PCI DSS require file integrity monitoring?

The PCI Security Standards Council defines FIM in its glossary as a change-detection solution that notifies when critical files change, and card businesses use it to show that control is in place.

What files should I monitor first?

Start with system binaries, configuration files, startup scripts and any file that holds security settings, then add application files once the noise is under control.

What's the difference between FIM and antivirus?

Antivirus looks for known bad files. FIM looks for any change to files you trust, so it can catch tampering that no signature knows about.

How do I cut down false alarms?

Mark planned changes as approved, exclude files that change all the time, such as logs, and review the rules after every major update.