In recent years in IT environments, some words including “hacked”, “hacker”, and “virus” have acquired a second meaning. In IT, these words can also loosely mean “something has happened or has changed and I don’t understand, please help me.” While it is possible this is a “hacker” or a “virus”, there can be other and entirely benign causes. This second and benign case and the entirely reasonable concern about changes or about nascent hardware problems is arguably more common around here, too. (And in the interest of full disclosure, those same words can also mean that IT or the app developer or the platform vendor screwed up, too.)
In short… Please explain what you are encountering.
”Things are changed” covers a whole lot of possible changes, for instance. And might cover a hardware problem with the display that can cause missed touches or so-called “ghost” touches, or can mean that y’all are unfortunately sharing an Apple ID, or can mean y’all have changed shared settings on some other device or some other Mac and iCloud has updated the settings on this device.
As for rather more expensive approaches such as “get new phone and new phone number”, if the exploits are being targeted, or if the problem is a trusted person locally, or if the problem is a misunderstanding or involves the user making the changes and then forgetting the changes were even made (cases of forgetfulness I’ve directly observed with folks I’ve supported), that expense won't address the issue.
Put more simply, what is happening here that has you concerned about your security? Please be specific, too.
