How can I check for malware on my iPhone?

BryanWWW wrote:

how can I check for malware on my phone

iPhone security compromises are typically expensive, rare, and (from what is known) targeted.

Password compromises and phishing and such, and compromised-password access into iCloud and such, and occasionally jailbreaks when your iPhone is out of your control, are more common.

If you suspect your iPhone is compromised, factory reset and re-install, and reset all passwords. Particularly passwords on your password-reset paths. mail, etc. Enable two factor authentication, if not already.

That reset and restore is unlikely needed here, absent some specific concerns.

If this is due to one of the website advertisements claiming your iPhone has malware (“you have (3) viruses!”, etc), those are bogus. Websites cannot scan your iPhone and cannot access your data. The adverts can lie though, and can seek to cause you to purchase rubbish add-ons you don’t need for problems you don’t have.

Some of the common scams: Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

All that written… Are you a political dissident, an investigative journalist, someone with access to sensitive or classified or financial information, a senior member of a large private or government organization, of interest to or an annoyance to somebody that is very rich, or similar case? if so, this reply does not apply to you. Do get specific help with your security.

Edit: As for the SMS delivery messages, those are common. And with the trackers in many web services embedded in many websites and the scanning embedded in free mail services and such, all sorts of folks do know when you order stuff. And I’d use the built-in anti-malware in macOS, and generally not an add-on. (One well-known add-on security app for macOS was caught selling user purchasing activities, and user web activities. I’d expect other security add-ons are also still selling that or similar data.) I’d definitely not recommend an add-on first-few-hops VPN client add-on.

Unless you jailbroke your phone or gave it to someone else while unlocked for an hour so they could jailbreak it, your phone doesn’t have any malware.