Most of the malicious ones just curl something in a postinstall script, scanners already catch that. The sneaky ones don't look malicious until they run, and three days may not help.
I don't think that HNers understand the recent supply chain attacks very well at all. I also don't think they realize the tests the SCA/package providers do to all the major packages.
Almost all these attacks try to reach out to external sites to steal your data. That is exceptionally hard to hide in any meaningful way.
You can make it much less suspicious. In particular, if you can compromise the package publishing process, and not just pushes to main, you can add your malicious code to binary artifacts, not to the source code.
Build provenance, maintainer alerts on new releases, tying releases to specific git tags, etc all help.