Finding things
Malicious packages
A typosquat has no CVE. Neither does a compromised release or a dependency confusion package, until well after it has run.
The published feed
OpenSSF publishes its malicious packages database into OSV, so those advisories arrive with everything else and are recognized as what they are: not a vulnerability in a package, but a package that is the attack.
What only the checkout can answer
An install hook that fetches and runs something, which is how most of these execute. A dependency pointed at a git URL or a tarball rather than a registry. A version specifier that floats, so the next install takes whatever was published last. A name one edit away from a popular one.
Never softened
A malicious package is never recommended for downgrade, whatever the reachability verdict says. It runs when it is installed, so "nothing calls it" is not a mitigation.
What it does not do
The offline signals are suspicions and are graded as suspicions. Socket does nothing but this and does it better; if malicious packages are your main worry, look at them too.
Every feature page carries one of those. The comparison page scores the same ground against five products people pay for, including the rows that go against us.