The Deno runtime is a JavaScript and TypeScript execution environment that runs code outside the browser. Unlike many older scripting setups, Deno uses a permission model: access to files, networks, environment variables, and subprocesses is denied unless it is explicitly granted. That design helps reduce accidental overreach and makes the runtime attractive for modern development and automation.
In cyber security, Deno matters because it can be used by both defenders and attackers. Security teams may allow it for legitimate developer workflows, while threat actors can abuse it to run attacker-controlled scripts under the cover of a trusted utility. That can make detection harder if monitoring focuses only on classic malware or common scripting tools. Defenses should watch for unusual Deno execution on endpoints, especially launches with broad permissions, suspicious command lines, or activity from user-writable paths.