MAL-2026-11501 Malicious code in simple-date-formatter-util-5 (npm)

The package is advertised as a date-formatting utility but its package.json postinstall script curls cloud-provider instance metadata endpoints (AWS 169.254.169.254, Alibaba 100.100.100.200, Tencent metadata.tencentyun.com and 169.254.0.23), retrieves the IAM security-credentials role, captures the output alongside ls -la /data/, and POSTs the collected data to attacker-controlled Interactsh (oast.fun) out-of-band subdomains such as safjhdvsfwzhieemkdzbgr54r0yjhrmok.oast.fun/metadata and ycrqyyjhwepdmhjifyccxss1hrks8lcd2.oast.fun/metadata. The tarball also ships postinstall.js, which enumerates ~/.ssh (reading.pub filenames and directory listing) and POSTs the results with username and platform to hardcoded IP 124.221.154.135:443/post over HTTPS. Behavior fires automatically on npm install, does not match the declared date-formatter purpose, and results in cloud IAM credential and SSH-context exfiltration to attacker infrastructure.

The OpenSSF Package Analysis project identified 'simple-date-formatter-util-5' @ 1.0.0 (npm) as malicious.

It is considered malicious because:

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

• The package executes one or more commands associated with malicious behavior.