MAL-2026-4644 Malicious code in power-platform-playwright-toolkit (npm)

On npm install, the package's postinstall script (postinstall.js) collects host identifiers and CI context — whoami, os.hostname(), os.platform(), cwd, CI, GITHUB_REPOSITORY, NODE_ENV — and sends them off the installer's machine via two channels: an HTTPS GET to 6v2j7oyzq0ehzolr4303sw1vwm2gqje8.oastify.com (a Burp Collaborator out-of-band callback host) at path /microsft?<querystring>, and a DNS lookup of <whoami>.6v2j7oyzq0ehzolr4303sw1vwm2gqje8.oastify.com to leak the username via DNS even when HTTPS egress is blocked. The package name impersonates Microsoft's Power Platform Playwright tooling namespace, and the exfil path token microsft (note the misspelling) serves as a campaign tag. The script self-describes as a 'security research canary' / 'Takeover By lobo', but installers have not consented to off-host data transmission and the captured data (GitHub repository identifier, CI flag, hostname, username) is direct reconnaissance value to whoever controls the OAST subdomain.

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.