my mac book after upgrading to catalina shows very often a msg for bad malware called "schedule"

Hi gavrielat,

Thanks for using Apple Support Communities! It looks like you're seeing pop-ups about some unintended software, and I'd like to help out.

How to block pop-ups in Safari has some steps to follow.

If you're still seeing that message, MalwareBytes is a great third-party program to download and run to remove unwanted adware or malware. MalwareBytes

Select the free download, and follow the steps provided.

Take care!

Does the message use the wording "..may damage your computer."?