If you downloaded a malware-infected version, it shouldn’t be able to access your accounts.

It remains unknown what the malware that found its way into the official SmartTube APK files can actually do. Thankfully, SmartTube is programmed to only request minimal account permissions and does not ask for any login information directly. Even if you granted the app access to your Google Drive for backup purposes, your Google account and general Google Drive files remain out of the app’s scope of permissions. Permissions regarding control of your YouTube account seem like the only thing that could have easily been exposed to the malware, as far as account access is concerned.

To be safe, factory reset anything you installed it on and double check for Google/YouTube account activity and permissions.

That said, since very little is know about the malware, you should assume the worst. If you use SmartTube and are concerned about your exposure to this malware, you should factory reset any device that had the app installed, especially if you installed or updated the app in November. It would also be a good idea to audit your Google account permissions and your YouTube account activity for anything unusual. Once your devices and account are in order, if you wish to reinstall SmartTube, be sure to only install the latest version through the codes/links above.

This is a bit clearer, or so I think anyway https://github.com/yuliskov/SmartTube/releases/tag/notification