What is file integrity monitoring?
File integrity monitoring (FIM) is a security control that continuously verifies the authenticity of file systems, operating system components, applications, and databases. It compares critical files to a trusted baseline to detect tampering, corruption, or suspicious modifications.
FIM works proactively, using a set of predefined rules to monitor for changes. Teams can use the information it provides for reactive forensic analysis. Organizations implement file integrity monitoring to do the following:
Detect the unauthorized modification of sensitive files and other critical business data
Prevent security breaches and data loss
Trigger real-time alerts
Facilitate forensic analysis
Most organizations that implement FIM find it most helpful to track operating system files, database files, application software files, archived logs and reports, and any other critical business files.
Consider integrating FIM with your other security products to provide comprehensive visibility across your entire environment and give your team the context they need to easily prioritize and act on notifications.
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Core benefits: How does FIM maintain data integrity?
Data is at the core of most business activities today, from development to payroll to customer relations. That makes data integrity central to maintaining a smooth, safe business operation for cloud and hybrid environments.
File integrity monitoring tools help ensure data integrity for the following:
Business continuity
Simplified regulatory compliance
Early detection of and response to suspicious activity
Below are the key benefits of FIM deployment:
| Benefit | Description |
|---|---|
| Discover breaches sooner | FIM continuously monitors the integrity of your most essential system files, including password databases (like /etc/shadow) that attackers might target to gain unauthorized access. Any unauthorized changes, such as unexpected modifications or suspicious code insertions, trigger immediate alerts for investigation. |
| Implement faster threat response | By identifying early signs of tampering, FIM lets your team act quickly to mitigate the situation. FIM also provides actionable insights to speed up your threat investigation and response efforts. |
| Expose security gaps | FIM can expose weaknesses in your IT infrastructure by identifying unauthorized or unintentional changes to critical system configurations that could leave your environment vulnerable. By identifying these weaknesses, FIM helps you proactively prioritize security improvements and harden your defenses before cyberattacks present themselves. (Note: FIM alone isn’t enough to resolve gaps.) |
| Simplify compliance | Regulations like PCI DSS (for credit card data) and HIPAA (for healthcare data) demand strict security controls to protect sensitive information. FIM continuously monitors the integrity of logs and compliance-related files to ensure that there is no tampering and to facilitate the collection of evidence for compliance audits. |
What are some obstacles to FIM?
File integrity monitoring software plays a major role in any organization’s security preparedness. As part of a layered defense, it flags files the moment they change so teams can immediately begin remediating critical security issues.
Yet there are also challenges to keep in mind. Here are a few:
Storage space: FIM solutions have heavy database storage requirements because they store file baselines and change information. The solution constantly compares files to this baseline, which can consume a lot of storage space, especially for large systems.
Excess alerts: Like any security tool, FIM can trigger false-positive alerts for legitimate changes, particularly during system updates or maintenance activities. However, integrating FIM with other security solutions will give teams better visibility into incidents as they occur.
Maintenance: To effectively implement and maintain your FIM solution, you need the necessary resources, including funding and dedicated team members, to conduct routine updates and establish procedures for acting on alerts.
A real-life example: The real consequences of data integrity failure
In July 2024, Nottingham University Hospitals (NUH) NHS trust experienced a data integrity incident after a critical file disappeared for maternity cases. The trust was able to recover the file, which led to the addition of 300 more cases to the ongoing investigation. This real-world scenario highlights how a single breach in integrity can reveal larger systemic issues.
The unreliability of essential data has caused frustration among patients, especially after law enforcement concluded that the deletion happened “intentionally or maliciously.” A statement from the Nottingham Affected Families Group said, “To know that there is most likely an individual who is capable of such behaviour is devastating for the already harmed and for the future of NUH safety. […] This is a patient safety emergency.”
Data integrity incidents like this not only jeopardize trust but also endanger real lives. Continuous FIM, however, can detect these incidents early, helping to mitigate damage to an organization’s reputation, compliance requirements, and—most importantly—the people it serves.
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The 3 phases of FIM: Detection, triage, and compliance
Effective FIM for cloud security follows a three-stage lifecycle to reduce risk and speed up incident response. Here are the three stages and the key action steps within each phase:
Detection
The detection phase identifies unauthorized or suspicious file changes quickly. Here are the key types of FIM detections:
Baseline comparisons: FIM defines a baseline for your system files, which allows you to detect any unauthorized changes.
Sensors: Modern FIM solutions use sensors to find changes within your content, permissions, or metadata. Agentless scanning can achieve this across your workloads and cloud environment.
Hash integrity checks: Hashing your files securely enables continuous scanning and detection of small changes or injections.
Real-time alerts: During an unauthorized change, you’ll receive a real-time alert with context for the affected asset.
Adopt agentless scanning with a cloud native application protection platform (CNAPP) like Wiz to consistently detect vulnerabilities and unusual activity.
Triage
Once you identify an issue, your team should work promptly to assess the severity of the vulnerability and develop an action plan. Here’s what triage includes:
Alert prioritization: FIM tools should offer filters to prioritize the most critical issues so your team can act quickly on what matters most.
Change context: You should automatically investigate relevant details during an event, such as the user, activity, and time the issue occurred. Your incident response plan should also define the person, action, and protocols in place when a red flag issue arises.
Automation: A FIM should incorporate tag-based monitoring and a security graph to map out active threats automatically. This helps your team act immediately based on contextualized visibility.
Remediation acceleration: Your security solution should provide guided steps to streamline incident handling and reduce your time to recovery.
Leverage contextual and prioritized alerts with a CNAPP to avoid alert fatigue and focus on the most impactful issues first.
Compliance
Along with keeping your serverless infrastructure secure, file integrity monitoring plays a pivotal role in compliance. The solution you choose should provide the following capabilities so you meet the standards in your jurisdiction and industry:
Audit logging and reporting: Logs provide a historical record of audits and document all changes and past alerts.
Standards alignment: When paired with all-in-one security solutions like a CNAPP, FIM measures compliance health against standards like PCI DSS, HIPAA, NIST, ISO 27001, and SOC 2.
Continuous assessments: File integrity monitoring with built-in compliance heat maps helps you measure compliance across your cloud environments.
Use Wiz to measure compliance health against over 100 frameworks.
Advanced FIM deployment: Agentless sensors and policy-as-code
As the cloud continues to grow more complex and threats evolve, advanced FIM solutions are necessary to monitor files across your serverless environments through automation.
Agentless sensors and policy-as-code both play critical roles for advanced FIMs. Here’s how:
Agent vs. agentless deployment patterns
Traditionally, FIMs have depended on agents installed on endpoints to monitor systems. This approach was helpful for legacy systems and teams that needed a more gradual method for tracking, but agent-based processes have limitations.
With an agent, teams often spend more time deploying resources. This lengthy, manual process negatively impacts efficiency and requires ongoing maintenance. An agentless approach, however, is more suited for complex cloud environments. Agentless FIMs, for example, automatically scan virtual machines, containers, and serverless assets to provide faster time-to-value and a less resource-intensive process.
Because of its automation capabilities, an agentless FIM can provide holistic visibility and scale with your growing cloud environments.
Policy-as-code rule bundles and automation
Codified data security policies automate your monitoring, which allows you to more efficiently keep your environment safe and shift your team’s energy toward higher-priority tasks.
For example, policy-as-code (PaC) defines your control policies with configuration files. With a CNAPP like Wiz, you can add YAML policies or integrate CI/CD to enforce protocols.
Your PaC process can also incorporate prebuilt rule bundles, particularly for compliance standards or enterprise-level policies. This, along with asset tags and event-driven response rules, helps you enforce key policies automatically. These centralized policies and enforcements benefit all companies, especially enterprise institutions.
Wiz: A more proactive approach to FIM
File integrity monitoring is vital for any organization that handles sensitive data—that is, every modern business. As a CNAPP solution that integrates FIM, Wiz gives you the proactive monitoring you need to safeguard all your systems and business-critical information.
Wiz detects unauthorized changes in the following ways:
Consistently scanning and comparing files to previous scans
Creating detailed FIM events for any file creation, deletion, or modification
Automating and configuring processes, including tag-based monitoring to cut through the noise and intelligent prioritization of specific resources
Tracking the integrity of system files to protect against threats like rootkits, which often tamper with system files and conceal their malicious activity for weeks or even months
Comparing file hashes to a known baseline and flagging file modifications as early as possible
Plus, Wiz rolls out FIM capabilities completely agentlessly, eliminating the need for extra software on the devices you’re monitoring. This unified, proactive approach minimizes tool overload and alert fatigue while empowering your security teams to automate and prioritize security across your cloud environment.
Schedule a demo to see how quickly and seamlessly Wiz can optimize your cloud security. Curious about where your security stands right now? Try our free Cloud Security Risk Assessment today.
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