Try using the unzip command to extract the sublime package into the /tmp dir (create a new subdirectory). You should be able to noodle around in the contents. More importantly, you should be able to checksum the files and compare to their open source versions on SublimeHQ/Packages (on github). Builds are tagged in that repo, so it should be easy to correlate.
If the checksums match, then you have a pretty high assurance that it’s a false positive. But if it still makes you nervous, you can look over the files.
Nothing in that package is executable, even as a plugin, so the odds of this being legit seem extremely small to me.