MAL-2026-18295 Malicious code in @capsense/core-ui (npm)

@capsense/[email protected] is published to the public npm registry under a scoped name at an implausibly high version, a shape used to override an organization's internal package of the same scope during resolution. The package's package.json declares preinstall, install, and postinstall lifecycle scripts that all invoke node beacon.js. beacon.js uses os.hostname(), os.userInfo(), and os.platform() to collect the installer's hostname, username, and platform, and transmits those identifiers to two attacker-controlled collectors: a subdomain of oast.pro (dbf2v9d8dg559apcd93guf6i7uxrn5coo.oast.pro) via DNS lookup and HTTPS GET, and webhook.site via query string. The beacon fires automatically on every npm install, before any code review of the package contents. Framing in the package description as a disclosure/PoC does not change the behavior: a successful dependency-confusion resolution causes installer-identifying data to leave the build or developer machine to third-party endpoints the installer did not configure.

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.

The OpenSSF Package Analysis project identified '@capsense/core-ui' @ 99.99.100 (npm) as malicious.

It is considered malicious because:

• The package communicates with a domain associated with malicious activity.