Why is File Integrity Monitoring Important?

File integrity monitoring (FIM), also known as the file integrity management, it is a security process that monitors the integrity of critical assets, including file systems, directories, databases, network devices, the operating system (OS), OS components and software applications for signs of tampering.

FIM tools rely on two different verification methods to verify the integrity of critical file systems and other assets: forensics or reactive auditing; and rules-based monitoring. In both cases, the FIM tool compares the current file with a baseline and triggers an alert in the event the file has been altered or updated in a way that violates the company’s predefined security policies.

Why is File Integrity Monitoring Important?

In recent years, cyberattacks, cybercriminals have become increasingly sophisticated in their use of malware and other methods to alter critical system files, folders, registries and data end endpoints to carry out advanced cyberattacks. If they are not caught, these hackers have the potential to disrupt business operations and steal data, intellectual property, and customer data.

The rapid acceleration of remote work, as well as an explosion of IoT devices has dramatically expanded the attack surface for cybercriminals, thus providing many points of access for these actors.

By routinely scanning, monitoring, and verifying the integrity of those assets, FIM provides an essential layer of protection for sensitive files, data, applications, and devices. Additionally, it expedites the identification of potential security issues and enhances the accuracy of the incident response team's remediation efforts.

File Integrity Monitoring Use Cases

Some common use cases for a file integrity management tool include:

Detecting a cyberattack

Critical OS or application-related files may need to be altered in the early stages of a complex cyberattack. The log files may even be altered by highly sophisticated attackers to conceal their actions. However, these modifications can still be detected by FIM tools because it compares the current file to a baseline rather than just the file logs.

Expediting threat detection, response and remediation

The company will have a better chance of stopping the breach before it causes significant or costly damage if it finds a threat early in the cyber kill chain. The organization's ability to spot an attack that other security measures might have missed is significantly improved by FIM.

Identifying weaknesses within the IT infrastructure

A few changes made by administrators or employees, while not malicious in nature, may inadvertently open the organization to risk. FIM helps identify these vulnerabilities and rectify them before they can be exploited by adversaries.

Streamlining compliance efforts

Organizations are facing an increasingly complex regulatory landscape. In virtually every industry, companies are obliged to monitor their IT environment and report select activity to maintain compliance with key regulations such as Health Insurance Portability & Accountability Act (HIPAA), General Data Protection Regulation (GDPR), ISO 17799 and Payment Card Industry Data Security Standard (PCI DSS).

How to Select the Right FIM Tool

While FIM is a critical capability for cybersecurity teams, many tools do not offer the customization, configurations, integrations and functionalities needed by the business.

Here are some questions to consider when evaluating file integrity monitoring tools:

Compatibility

• Is this file integrity monitoring solution compatible with all other aspects of the organization’s existing cybersecurity architecture?
• Is this FIM tool capable of supporting the company’s existing file integrity policies?

Customization

• Does this file integrity monitoring software help automate and streamline regulatory compliance efforts unique to the organization?
• Can the FIM solution support additional functionalities that may be needed by the business in the future?

Configuration

• How quickly can the FIM software be updated? What does the QA testing process look like to ensure all existing configurations work properly?

Ease of Use

• How much of the file analysis is automated by the FIM tool?
• Can security controls in the FIM solution be easily turned off and on, or updated as needed?
• How are alerts from the monitoring tool delivered to the IT team?
• In what format is alert data presented to ensure that information is actionable?

Integration

• How does the FIM tool integrate within the organization’s existing cybersecurity architecture, including the SIEM?
• What support does the vendor provide to ensure that the FIM tool is properly integrated with other tools and technologies?

A good FIM tool will monitor all components of your IT environment, including:

• Network devices and servers
• Workstations and remote devices
• Databases, directories, OS, and middleware
• Cloud-based services
• Hypervisor configuration, and Active Directory

At minimum, an enterprise solution should provide change management, real-time logging, centralized logging and reporting, and alerts. Often, file integrity monitoring is part of a broader auditing and security solution that will also include capabilities such as automated rollback of changes to an earlier, trusted state. An ideal solution will give you clear, rapid information on the who, what, where, and when for every access and change event.