Pre-fetch is the act of loading content in advance before a user explicitly requests it. Browsers and operating systems do this to reduce waiting time, for example by preparing pages, files, or network resources they think will be needed next. In normal use, pre-fetching improves performance and makes web browsing feel faster.
In cyber security, pre-fetch matters because attackers can abuse it to stage harmful content quietly. A file may be fetched by the browser and stored in cache before the victim sees anything suspicious, making the content look like ordinary web data instead of a direct download. That can help disguise payloads, delay detection, and blur the boundary between browsing and local execution. Defenders should watch for unusual browser-to-shell transitions, unexpected cached objects, and users being instructed to run content that appeared through normal web activity. Pre-fetch itself is not malicious, but it can be part of a delivery chain that makes an attack easier to hide.