post-install seems like it shouldn't be necessary anyway, let alone need shell access. What are legitimate JS packages using this for?
replies(4):
Socket:
- Sep 15 (First post on breach): https://socket.dev/blog/tinycolor-supply-chain-attack-affect...
- Sep 16: https://socket.dev/blog/ongoing-supply-chain-attack-targets-...
StepSecurity – https://www.stepsecurity.io/blog/ctrl-tinycolor-and-40-npm-p...
Aikido - https://www.aikido.dev/blog/s1ngularity-nx-attackers-strike-...
Ox - https://www.ox.security/blog/npm-2-0-hack-40-npm-packages-hi...
Safety - https://www.getsafety.com/blog-posts/shai-hulud-npm-attack
Phoenix - https://phoenix.security/npm-tinycolor-compromise/
Semgrep - https://semgrep.dev/blog/2025/security-advisory-npm-packages...
The malware could have been a JS code injected into the module entry point itself. As soon as you execute something that imports the package (which, you did install for a reason) the code can run.
I don't think that many people sandbox their development environments.
To me it's quite unexpected/scary that installing a package on my dev machine can execute arbitrary code before I ever have a chance to inspect the package to see whether I want to use it.