OpenSSF/OSV advisory MAL-2026-11485 confirms this npm version as malicious. The package.json postinstall script runs on every npm install and uses curl to probe cloud instance-metadata services (AWS 169.254.169.254, Alibaba 100.100.100.200, Tencent metadata.tencentyun.com, 169.254.0.23), writes their responses to /tmp, and POSTs the concatenated contents together with a listing of /data/ to an attacker-controlled OAST collector at ycrqyyjhwepdmhjifyccxss1hrks8lcd2.oast.fun...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in simple-date-formatter-util-2 (npm)
Details
The package.json postinstall script runs on every npm install and uses curl to probe cloud instance-metadata services (AWS 169.254.169.254, Alibaba 100.100.100.200, Tencent metadata.tencentyun.com, 169.254.0.23), writes their responses to /tmp, and POSTs the concatenated contents together with a listing of /data/ to an attacker-controlled OAST collector at ycrqyyjhwepdmhjifyccxss1hrks8lcd2.oast.fun. Cloud IMDS endpoints return role credentials for the installer's instance, so the beacon exfiltrates cloud credentials on install. The tarball also ships a postinstall.js that enumerates the installer's ~/.ssh directory and POSTs the collected data with username and platform fields to https://124.221.154.135/post. The package advertises date-formatting utility functionality; none of the observed behavior relates to that purpose.
## Source: ghsa-malware (6e2619c38c0a6e4c2bf346194ff3de102d18ef08ddd7c864c4470d17d62837b8) 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.
Decision reason
OpenSSF Malicious Packages via OSV confirms simple-date-formatter-util-2@1.0.0 as malicious (MAL-2026-11485): Malicious code in simple-date-formatter-util-2 (npm)