What is an EXE file or executable file?
When a user interacts with a file icon on a computer, the system is able to promptly carry out a set of encoded instructions that are stored within the executable file (referred to as EXE file). While there exist numerous formats for executable files, the majority of them are recognized by having an extension of EXE file.
Certain executable file formats have the capability to operate on any suitable system independently, without requiring additional software. However, these files pose a significant security vulnerability.
Among the file types commonly found in Windows systems are EXE, BAT, COM, CMD, INF, IPA, OSX, PIF, RUN, and WSH.
Executable files in Windows are identified by the file extension EXE. While not all executable files are labeled as EXE files, it is important to note that all EXE files are indeed executable files.
How do EXE files function?
An executable file format exclusive to Windows is recognized as an EXE file. Whenever a user initiates an executable file or when a specific event triggers it, the computer executes the instructions contained within the file. Executable files are comprised of binary machine code that is generated through the compilation of the source code.
This fundamental code provides instructions to the Central Processing Unit (CPU) of your computer on executing the program. The CPU processes the machine code and directs the computer hardware on tasks to perform.
Executable files store the instructions that a computer executes when prompted by a user or triggered by an event. These files contain the binary machine code derived from the source code.
The CPU of a computer is responsible for receiving instructions on executing a program from low-level code. The processor is the component that interprets the machine code to direct the computer's hardware operations.
Executable files contain a series of commands that instruct the computer to perform specific tasks by communicating directly with it. On the other hand, a separate program is required to interpret or process data files before the computer can utilize them. Scripts and data files are typically written in plain, unencrypted text format.
Individuals have the option to utilize an Integrated Development Environment (IDE) or a basic text editor to generate executable files. Those individuals aiming to transform a text editor file into machine code will require an extra compiler.
The Integrated Development Environment (IDE) streamlines the compilation process by automatically detecting syntax errors and highlighting different syntax elements. It is designed to automate the compilation process, identify syntax errors, and highlight various syntax elements.
How an EXE file is executed?
Executable files are designed to start running as soon as they are opened, which occurs when a user initiates the opening process. This process can vary depending on the specific operating system being used. Here is how the executable file is typically launched:
- In systems that have a Graphic User Interface (GUI) as part of the Operating System (OS), users can open the file by either clicking on the file name or its icon.
- To illustrate, users of Microsoft Windows can simply double-click on a file to execute it.
- On the other hand, in operating systems that rely on a Command Line Interface (CLI), users need to enter the file name along with any necessary syntax into the CLI and then press Enter to run the file.
- For instance, in Linux or Unix systems, to execute a file named "java," users are required to prepend a period and a slash before the filename. This is done by typing "./java" in the CLI.
Sometimes, an executable (EXE) file can be triggered passively. Windows operating system, for example, is equipped with functionalities known as AutoPlay and AutoRun, which initiate the execution of files automatically upon certain triggers.
As an example, the USB firmware initiates automatically upon connecting a USB device. Similarly, during the computer's startup process, any executable files present in the Windows startup files are also launched automatically.
The EXE file extension is specific to Windows executable files and is commonly utilized. On the other hand, Mac executable files are recognized by the APP extension. To run an EXE file on a Mac operating system, users need to utilize the Boot Camp application, a virtual machine, or an emulator that enables a Windows OS environment.
Execution of content within web pages:
When the web browser boosts its utilization of the JavaScript interpreter, it enables the dissemination of executable code over the internet in the shape of JavaScript scripts.
The illustration provided demonstrates a simple JavaScript application integrated within a webpage.
<html>
<body>
<head><title>Example for Factorial numbers</title></head>
<script language="JavaScript">
document.write("<h2>Factorial numbers</h2>");
for(i = 1, fact = 1; i < 5; i++, fact *= i) {
document.write(i + "! = " + fact);
document.write("<br>");
}
</script>
</body>
Activating the run option in the online compiler triggers the generation of outputs in the form of an executable file.
Output
Issues with executable files and malware
Sometimes, malware can be detected within EXE files. Malicious executable files might be concealed under valid file extensions by those who create malware.
The characters after the last dot in a file name signify the file type. File extensions may not always be visible in Windows, which can make it difficult to identify the format of a specific file.
Consider a scenario where a file is named name.pdf.exe. To the user, this file may appear as a PDF because the file name displays as filename.pdf without the extension. If the user clicks on this file, they may expect to open a PDF document. However, instead of opening a PDF, an executable file with harmful code is executed, leading to the user's computer being infected with malware.