Executables are a vital file type, required to install many of the desktop applications and tools we rely on day to day. They can also be used to inject malware into our system, however, which makes them a potent security threat. Below, we’ll review how legitimate executables work and discuss how malicious executable threats can be mitigated with straightforward security policies.

What are Executables?

Executables are files containing binary machine code which is explicitly intended to run (execute) on a certain computer operating system. These files make it extremely easy to distribute software programs across multiple systems through simple file sharing mechanisms. They’re commonly used to initiate the installation of commercial products like licensed business applications, computer games, and many more examples.

An executable file can be thought of like a list of instructions. After an executable file is launched on a compatible system, the system will load the file’s contents into memory and work its way down the file’s list of instructions, ultimately running the executable file’s program.

Why are Executables Dangerous?

Since executable files are designed to run programs directly after file opening, they present an ideal method for threat actors to install malicious code – including viruses, malware, and a variety of other threat types – onto a victim’s operating system. Attackers can email executable files from compromised external devices and convince victims to open (and therefore execute) their malicious files using social engineering tactics. They can also share these files directly through vulnerable file upload portals for distribution to a wide range of victims who have access to their target application’s database.

Executable files can also be distributed through far more insidious means to avoid detection from poorly configured security policies. For example, attackers can give executable files misleading names, so they appear to be an entirely different file format than they are. A file with a seemingly innocent name like “newemployeeheadshot.jpg” might contain executable contents, and this file might then successfully avoid detection from system users who assume the file contents safely match the simple, descriptive title. Additionally, attackers can bury executable files in compressed archives alongside a number of valid documents. Once files are extracted from these folders, the executable file can lay dormant until it’s opened by a downstream system user at some point in the future.

How can Executable File Threats be Prevented?

Preventing the distribution of malware within any system always begins with user accountability. System users should be regularly trained to identify illegitimate files, and they should know to avoid clicking on suspicious attachments shared from any external source.

It’s equally critical to scan files for malicious content as they enter a system at the network edge, before they enter specific applications, and while they reside in cloud storage instances. The Cloudmersive Advanced Virus Scan API can be deployed in any of those locations, and API administrators can configure custom policies in its request body (or from their Cloudmersive account page) to block executable files from entering their system. This API ignores superficial information like file names, extensions, and headers, instead performing in-depth content verification to detect and report each file’s actual encoding.

This API also scans files for viruses and malware, referencing a continuously updated list of more than 17 million virus and malware signatures in the process. Further, it provides additional request policies for blocking more non-malware threats than just executables, with coverage including scripts, macros, XML external entities, and much more. Any files found to contain viruses, malware, or non-malware threats blocked by custom policies in the API request body will receive a CleanResult: False response. This uniform threat value makes it easy to categorically delete (or quarantine) malicious files in a single API request.

For more information on the Cloudmersive Advanced Virus Scan API, please do not hesitate to reach out to a member of our sales team.