The @uwr/colors npm package version 1.3.6 includes a postinstall script that executes os.hostname() to obtain the installer's machine hostname and then performs a DNS lookup to a domain under oastify.com, a known Burp Collaborator service used for out-of-band data exfiltration. This behavior leaks sensitive environment information during installation without user consent. The package's minimal functionality and empty author field indicate it is likely a malicious package designed for reconnaissance or dependency confusion attacks targeting internal namespaces.

The vulnerability results in unauthorized leakage of the installer's machine hostname to an external attacker-controlled domain during package installation. This can aid attackers in reconnaissance and potentially facilitate further targeted attacks. There is no indication of code execution or other direct compromise beyond information leakage.

No official patch or remediation is currently available. Users should avoid installing the @uwr/colors package version 1.3.6. Verify package authenticity before installation, especially for packages with unverified authors or suspicious scopes. Monitor for updates or advisories from trusted sources regarding this package.