Apple has some of the strictest rules to prevent malicious software from landing in its app store, even if on occasion a bad app slips through the net. But last year Apple took its toughest approach yet by requiring developers to submit their apps for security checks in order to run on millions of Macs unhindered. The process, which Apple calls “notarization,” scans an app for security issues and malicious content. If approved, the Mac’s in-built security screening software, Gatekeeper, allows the app to run. Apps that don’t pass the…