MAL-2026-10748

    Dashboard / Malicious Package / MAL-2026-10748

    MAL-2026-10748

    Published: 16 Jul 2026Last Modified: 16 Jul 2026

    Summary: Malicious code in string-formatter-pro (npm)

    Details: Source: amazon-inspector (966ebbfb039acea9e1f98c5f74f13e2aab1617e371719bc9543315702dbd67cd) The package advertises itself as a string-formatting utility whose main module exports only a trivial one-line capitalize() function, but ships a postinstall.js lifecycle script that runs automatically on `npm install`. postinstall.js issues a chain of curl commands against cloud instance-metadata endpoints (AWS IMDS at 169.254.169.254, Alibaba at 100.100.100.200, Tencent at metadata.tencentyun.com, and 169.254.0.23) to harvest IAM security credentials, EC2 user-data, the instance identity document, and the host's OpenSSH public key, then POSTs the aggregated output plus a directory listing of /data/ to the hardcoded destination pwpzhsrbtvmfqrqr7onqcwnrcii960up.oastify.com (a Burp Collaborator subdomain). The trivial library surface is a decoy for install-time credential theft against the installer's cloud environment.

    References: https://www.npmjs.com/package/string-formatter-pro/v/1.0.1, https://www.npmjs.com/package/string-formatter-pro/v/1.0.0

    Affected packages

    Package

    Name: string-formatter-pro

    Purl: pkg:npm/string-formatter-pro

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    1.0.1
    1.0.0