More useful than reading the code, in most cases, is looking at who's behind the code. Can you identify the author? Do they have an identity and reputation in the space? Are you looking at the version of the package they manage? People often freak out about the number of packages in such ecosystems but what matters a lot more is how many different people are in your dependency tree, who they are, and how they operate.

(The next most useful step, in the case where someone in your dependency tree is pwned, is to not have automated systems that update to the latest version frequently. Hang back a few days or so at least so that any damage can be contained. Cargo does not update to the latest version of a dependency on a built because of its lockfiles: you need to run an update manually)