What is file protection?

Files are a primary vehicle for cyberattacks, with every document received from an external source representing a potential security threat. They are routinely used to deliver malware, ransomware and other malicious code into organizational systems via email attachments, file upload portals, cloud storage platforms and collaborative applications. Whether it’s Word, Excel, or PowerPoint documents, PDFs or image files, threat actors exploit their trusted status to bypass perimeter defences.

Malicious files are routinely used in targeted attacks, phishing campaigns and supply chain compromises. Ransomware gangs are also focusing on file-based tactics, frequently using malicious downloads, phishing emails and cloud-based collaboration platforms to deliver ransomware payloads. 

In addition, credential-harvesting attacks use weaponized file attachments to deploy keyloggers or steal login credentials, granting unauthorized access to sensitive networks. Attackers also use malicious files to exfiltrate intellectual property or disrupt operations through denial-of-service attacks. Cloud storage and collaboration tools are also targeted because perimeter-based security approaches are no longer sufficient to address the risks.

With one in every 100,000 files containing potentially malicious content and 98% of these threats going undetected by antivirus solutions for up to 18 days, attackers continue to exploit file-based security vulnerabilities to infiltrate networks.

File protection technologies

File protection is the set of technologies, policies and processes that secure digital files from unauthorized access, tampering and malicious payloads. As such, they play a critical role in preventing malware, ransomware and data exfiltration, particularly as organizations routinely rely on file-sharing platforms, cloud storage and collaboration tools.

To address the various file-based security risks, public and private sector organizations have traditionally implemented a combination of detection-based and prevention-based strategies. For example, detection-based tools, such as antivirus software, sandboxing solutions and endpoint detection and response (EDR) systems, focus on identifying known threats by relying on malware signatures or patterns of suspicious behavior. While these technologies are important components in delivering effective all-round protection, they are increasingly challenged by the rise of AI-generated, polymorphic and evasive malware that can bypass their processes.

In contrast, prevention-based strategies aim to neutralize threats before a file ever reaches the end user. Options include file flattening, which removes active content by converting documents into static images. While this can reduce the risk of embedded threats, it also strips away the file’s original functionality, limiting usability and collaboration.

Organizations also use encryption and digital signatures to protect files, ensuring that their contents remain confidential and unaltered during transmission. However, while these measures help verify integrity and authenticity, they do not remove threats that may already be embedded within the files themselves.

To fully address file-based threats, security teams are increasingly turning to Content Disarm and Reconstruction (CDR), a proven set of technologies that treat all files as potentially malicious, remove any harmful elements and rebuild them into clean, fully functional versions that conform to known safe standards. Unlike flattening, CDR preserves both security and usability.

The role of Content Disarm and Reconstruction (CDR) in file protection

Looking at CDR more closely, the process works by deconstructing each file down to its most basic components and inspecting them for compliance with the manufacturer’s known good specifications. Any elements that deviate from this standard, such as embedded macros, malformed structures, hidden scripts or unauthorized active content, are stripped out. The file is then rebuilt into a clean, fully functional version that is visually identical to the original but free from exploitable risk.

Unlike file flattening techniques that convert documents into static, read-only formats, CDR preserves usability and document integrity. Users can open, edit and share files without disruption and without compromising on security.

Effective file protection is also an inherent element of the zero trust cybersecurity model. In this context, no file should be inherently trusted, regardless of its source. Perimeter defenses alone are no longer sufficient, and placing implicit trust in attachments from internal users, third-party vendors or cloud applications can expose serious vulnerabilities.

A zero trust approach to file protection starts from the assumption that every file could be malicious. To manage this risk effectively, the model enforces strict security controls. These include limiting access rights through least-privilege policies, which help contain the impact of any successful breach. It also involves continuous monitoring to detect abnormal file activity that may indicate compromise, alongside strong verification of user and device identities before allowing file interactions.

Critically, zero trust requires that security technologies do not rely on detecting threats only after they emerge. Instead, protection must be proactive, neutralizing risks before files ever reach the user.

Ultimately, CDR provides organizations with a way to ensure that only clean, fully functional files enter their environment. This helps enforce consistent, proactive protection across complex and distributed technology infrastructures.

Glasswall CDR - Eliminate malware before it reaches your network

Glasswall takes a fundamentally different approach to file protection by proactively eliminating threats rather than trying to detect them. Our patented Content Disarm and Reconstruction (CDR) technology treats every file as untrusted and rebuilds it to a known good standard based on the file type’s original specification.

This process removes potentially malicious content, such as embedded macros, malformed code, and active elements, while maintaining full usability and preserving the visual integrity of the document. The result is a safe, clean file that is instantly available to the user, free from threats and without the delays or disruption associated with traditional detection-based tools.

Unlike antivirus, sandboxing or file-flattening solutions, Glasswall does not rely on prior knowledge of malware or indicators of compromise. Instead, we deliver zero-trust file protection that is both deterministic and scalable. Glasswall CDR integrates easily into existing security architectures, whether deployed in the cloud, on-premises or within isolated environments. It is trusted by defense, government and commercial organizations worldwide to eliminate blind spots created by reactive security tools and to ensure that only fully functional, threat-free files are allowed into critical systems.

How our CDR protects files

Glasswall CDR employs our patented 4-step approach to protect government agencies and organizations against file-based threats. Unlike other cybersecurity solutions, we don’t try to identify the malicious code – we simply remove the ability for it to exist in the file altogether.

1. Inspect

Breaks down the file into its constituent components. Validates the file’s structure against its specification

2. Rebuild

Unknown and invalid file structures are repaired in-line with the file’s specification

3. Clean

Removes high-risk file structures that contain active content, based on configurable policy

4. Deliver

Semantic checks ensure the file’s integrity. The safe and fully functional file is now ready to use

To find out more about our suite of CDR technologies, click here.