Filejpgexe

Filejpgexe is a term used to describe a class of disguised executable files that use a misleading filename to appear as a jpg image while actually being an executable. It is a form of masquerading commonly employed in malware distribution and phishing campaigns.

Mechanism and characteristics follow a double-extension pattern. In Windows, file extensions can be hidden by default, causing a file named something like invoice.jpg to actually be invoice.jpg.exe. When extensions are hidden, the true nature of the file is not immediately clear to the user. Attackers may also place files with names such as image.jpg in archives or email attachments that, once opened, execute without the user realizing the risk. This technique leverages user trust in image files and the ubiquity of JPEGs to prompt a click or execution.

Risks and contexts of use include malware delivery, such as Trojans, ransomware, or spyware, as well as credential theft and data exfiltration. Filejpgexe variants can appear in email attachments, malicious downloads, or drive-by infection scenarios, exploiting social engineering and security gaps in user behavior and endpoint protection.

Detection and mitigation focus on reducing ambiguity around file types and improving user awareness. Best practices include configuring systems to show file extensions, using reputable antivirus and endpoint protection, and applying strong email and web filters. Users should verify the source of any unexpected file, avoid opening files from unknown senders, and rely on digital signatures and sandboxing for executable content.

Related concepts include double extensions, masquerading, and phishing.