What are “malicious attachments”?

Malicious attachments refer to files that, when opened, can install harmful software (often known as malware) on a device. These attachments are often disguised as legitimate documents, images, or other file types to trick users into opening them. Once opened, they can execute harmful code that may steal sensitive information, compromise system security, or cause various forms of damage to the operational integrity of the device. Understanding this definition is crucial in recognizing the importance of exercising caution when handling attachments in emails or messages, particularly those from unknown or suspicious sources.

Files that come with printer software typically do not fit this definition, as they are generally included as part of a legitimate software installation. Meanwhile, encrypted files, while secure in their information encoding, do not inherently constitute a threat unless they contain malicious content. Lastly, files sent from known contacts can also be harmful if the sender's account was compromised, demonstrating that the source alone does not guarantee safety. Thus, the primary characteristic of malicious attachments lies in their potential to harm upon being opened.