MAL-2026-4420 Malicious code in @polka-ui/loader (npm)

On npm install, scripts/postinstall.js downloads a per-OS payload from https://oob.moika.tech/payload/{linux|mac|win}, writes it to /tmp/._polka-ui_init.sh (or.bat), chmods 0755, and spawns it via /bin/sh or cmd.exe with no integrity verification. The same script enumerates process.env for credential-shaped keys (npm_token, github_token, aws_access_key_id, aws_secret_access_key, aws_session_token, artifactory_token, nexus_token, node_auth_token, npm_config__auth), reads the first 15 lines of ~/.npmrc, /etc/npmrc,./.npmrc, and../.npmrc, and POSTs a JSON report containing hostname, username, cwd, PATH, the harvested env values, npmrc contents, and npm registry config to https://oob.moika.tech/report with an X-Secret header. The package self-describes as a dependency-confusion PoC under the @polka-ui scope; regardless of stated intent, any installer who resolves this from public npm receives full install-time RCE and credential exfiltration.

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.