File Integrity Monitoring Tools 2026
File integrity monitoring (FIM) watches the things on a host that should never change quietly: system binaries, configuration files, the Windows registry, application files, and sensitive directories. When something is added, modified, or deleted, FIM records who changed it, when, and what the before and after looked like, then alerts when the change falls outside an approved baseline. Security and compliance teams lean on it for two reasons. It catches tampering that signature-based tools miss (a poisoned config, a planted web shell, a modified scheduled task), and it satisfies explicit mandates like PCI-DSS Requirement 11.5. Unlike EDR, which hunts behavioral threats across processes and memory, FIM is narrow and deterministic. It answers one question well: did this protected thing change, and was that change authorized.
We cover 1 File Integrity Monitoring tool, 0 free and 1 commercial.
Accuracy and depth improve over time. Last reviewed Sep 2026. Is something off? Reach out.
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New to this category? What is File Integrity Monitoring (FIM)?
How to choose File Integrity Monitoring tools
- Noise control is the whole game. Look for change reconciliation against patch windows, package managers, and ticketing or change-management systems so legitimate updates auto-close instead of paging someone at 2am.
- Check coverage across the surfaces you actually run: Linux and Windows file systems and the registry, but also configuration files, databases, network-device configs, and cloud or container images if that is where your sensitive state lives.
- Choose between agent-based and agentless collection. Agents give real-time, who-did-it detail and kernel-level event capture; agentless suits ephemeral or locked-down hosts but usually means scheduled scans and weaker attribution.
- Demand baseline and policy management that scales. Per-host hand-tuning collapses at fleet size, so favor templates, inheritance, and policy-as-code over manual rule lists.
- Map the tool to the exact compliance text you answer to. PCI-DSS, HIPAA, SOX, NERC CIP, and CIS Benchmarks each phrase FIM expectations differently, and prebuilt policy packs plus audit-ready reporting save real work.
- Confirm where the evidence goes. Tamper-resistant, off-host log storage and clean SIEM, SOAR, or syslog forwarding turn FIM events into investigable trails rather than alerts that die on the endpoint.
File Integrity Monitoring Tools FAQ
Common questions about File Integrity Monitoring tools, selection guides, pricing, and comparisons.
File integrity monitoring is a control that detects unauthorized changes to critical files, configurations, and registry entries on a host. It establishes a known-good baseline, then watches for additions, modifications, and deletions, alerting when a change falls outside approved activity. Teams use it to spot tampering, planted malware, and misconfigurations, and to satisfy compliance mandates like PCI-DSS.
FIM and EDR answer different questions. FIM is deterministic: it tells you a specific protected file, config, or registry key changed, and whether that change was authorized. EDR is behavioral: it hunts suspicious process activity, memory injection, and attack patterns across the endpoint. FIM catches quiet tampering that signature and behavior tools miss, so most mature programs run both rather than treating one as a substitute.
Start with alert noise. The best tools reconcile changes against patch cycles and change-management systems so approved updates close automatically. Then check surface coverage (files, registry, databases, cloud images), agent versus agentless collection, baseline management at fleet scale, and compliance policy packs for the frameworks you answer to. Finally, confirm events forward cleanly to your SIEM with tamper-resistant evidence storage.
FIM directly addresses PCI-DSS Requirement 11.5, which calls for a change-detection mechanism on critical files with alerting and at least weekly comparisons. But PCI compliance spans many other controls, from network segmentation to access management, so FIM is one required piece, not the whole picture. Pick a tool with prebuilt PCI policy templates and audit-ready reporting to make assessor evidence straightforward.
Open-source options handle baseline creation and change detection well and are common on smaller or budget-constrained fleets. The gap shows up at scale: centralized policy management, change reconciliation to cut false positives, role-based access, compliance reporting, and support. If you have a handful of servers and engineering time, open source can be enough. If you are passing audits across hundreds of hosts, commercial tooling usually pays for itself in reduced operational overhead.
