Malware Apps

No ... but you should take a few precautions, like:

• Don't jailbreak your phone.
• Keep your iPhone's iOS updated.
• Don't install apps without doing a bit of research about the developer. Note that apps, from the Apple App Store, have passed multiple levels of scrutiny before they are made available ... but even that is not 100% foolproof.
• Do give out your Apple ID credentials to anyone.

HighhatSteppers Said:

"Malware Apps: With Apple Security, do I need additional protection?"

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Making a Mac Secure:

I. Scan your Mac for Malware: 

Use MalwareBytes for Mac --- This is software that searches for malware/adware, and is developed by long time users of these forums. So, scan with it and then remove what is found. Once removed, uninstall MalwareBytes for Mac. Then restart the Mac.

Downloads:

1. Malwarebytes Anti-Malware for Mac
2. Malwarebytes Uninstaller

II. Report Items to Apple:

Take some screenshots of issues, and forward it off to Apple. Use my User: Using the Photos App to Report Scams - User Tip

HighhatSteppers wrote:

With Apple Security, do I need additional protection?

No.

The built-in iPhone malware scanning and malware removal tools, and the scanning performed by the app store, among other features, works.

Add-on anti-malware apps — which you generally don’t and won’t need — also cannot scan your storage.

To learn more about this, start here: Apple Platform Security - Apple Support

HighhatSteppers Said:

"Malware Apps: With Apple Security, do I need additional protection?"

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As for an iPhone...

Blocking Out Spammers:

Use Malwarebytes Mobile Security. The free version blocks popups. The paid version blocks out known spam numbers. So, consider using it. Read the following post to see how to use this software: Blocked numbers - Apple Community

Phone spammers can and variously do switch “calling” numbers for every call. This no different from email spammers, where the ”sender” email addresses are routinely spoofed. If the spammers don’t switch “calling” numbers, they’re trivial to block using existing capabilities. And Safari can block pop-ups.

MrHoffman Said:

"Phone spammers can and variously do switch 'calling' numbers for every call. This no different from email spammers, where the 'sender' email addresses are routinely spoofed. If the spammers don’t switch 'calling' numbers, they’re trivial to block using existing capabilities. And Safari can block pop-ups."

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As for Malwarebytes Mobile & Spoofing:

MalwareByte Mobile, as I understand it, looks for reputation of what has been blocked and why in the past. I still get texts from my Contacts. But, it has always blocked out spoofs, if something doesn't seem right from the App's POV.