ASAR is Electron’s archive format for bundling an app’s JavaScript, assets, and other resources into a single packaged file. It is designed for convenience and portability, letting developers ship a desktop app with most of its runtime content stored in one archive.
In cyber security, ASAR matters because attackers can hide malicious or modified code inside a package that still looks like a normal application. A trojanized Electron app may run its visible features while also loading hidden scripts or contacting a second-stage payload. Defenders often inspect ASAR contents, compare hashes, and monitor runtime behavior to spot unexpected files, altered resources, or suspicious child processes. ASAR is not malicious by itself; the risk comes from trust in packaged software and the difficulty of noticing what changed inside the archive.