And if you want to get the same "we serve the code directly" benefit as well, you can set up an npm proxy and require its use. That way you're getting a very specific version, and downloading that version from a location you control.

(And then for the ultimate level of "slow your project to a crawl, but hey at least it's really secure", you can only allow versions that pass an internal security review to be added to the proxy and disable automatic fetching of un-cached versions. Ain't no sneaky code getting in unawares there!)