(Ex) Spouse has paid a company to hack my account.

Actually hacking an Apple mobile device is actually extraordinarily difficult to do, and to date, no credible account of any remote hacking of a device has been reported.

Hacking your AppleID is a different issue, especially if you don’t use 2 factor authentication, and only use a password. Especially so if you use easily guessed or brute force hacked passwords.

Once someone has compromised your AppleID, then can even restore a device they have with your own iCloud backup, alter things in your backup and put it back in iCloud. If you restore from that altered backup, then yes they can add spyware, key loggers and so forth to your device. And they don’t even need to pay anyone for that - there are open source and commercial apps that will allow one to spy on someone via their iPhone or iPad if the person using the app knows their victims AppleID and can use it just as their victim normally uses their AppleID. If the AppleID is compromised, it’s really quite easy to wreak havoc on someone’s devices and privacy.

But the key was gaining access to your AppleID so they could login to iCloud as you.

If you use a strong AppleID password, enable 2 FA, and keep your trusted devices and contact numbers private, it is extraordinarily difficult for anyone to compromise your AppleID.

Thus is precisely a prime reason Apple is requiring 2FA with AppleIDs. Your AppleID is the key to everything you have with regard to your Apple devices. If you don’t keep access to your AppleID secure, then nothing else really matters in terms of whatever devices you own and use.

If you think your Apple ID has been compromised - Apple Support

It isn’t easily hacked. It is extremely expensive to hack an iPhone. In one instance it cost the FBI $980,000. And they had physical possession of the phone, which is a requirement to hack an iPhone. It is easier to hack your Apple ID if you don’t have a strong password on it and don’t have 2 factor authentication, so I hope you do have those requirements met. As far as the phone is concerned, if he has had physical possession of it at any time for more than a few minutes restore it to factory settings using DFU mode—>How To Put An iPhone In DFU Mode, The Apple Way

If you think someone is trying to hack your account or phone that is a felony, and anyone who tries it will go to jail, so contact the police.

DPJ88 wrote:

My spouse has actually paid a company to hack my phone in the past and is trying to do the same again as per his own emails to this company (verified-hackers.com)

Unless he has, or someone has, also jailbroken your phone, it is highly unlikely this will happen.

Lots of claims to phone hacks are made but none are proven.

It is more possible to hack your accounts. Change your passwords and where possible, add two factor authentication to them. This means physical control of your phone will be required to sign in

You need to check for weak links in your security. Your iPhone 11 Pro Max running iOS 14 is literally the strongest and virtually unbreakable link, but there are others weak links you can look at.

The single biggest weak link for most people is their email address. Specifically if you are using a free email such as Gmail, Hotmail/Live/Outlook, AOL, Yahoo, etc. you should use a computer web browser (if possible, or your iPhone's Safari web browser) and log into your email that way so you can access your email-provider's account settings. You cannot do this via the iPhone Mail app you probably normally use. From your email-provider's account page buried deep in the settings you can see if any forward rules or filters have been set up that send him a copy of your emails.

You should also take a deep-dive into your social media accounts' settings page, again using a web browser (ideally a computer web browser) to see if anything has been set up there that could be giving him access.

You should also contact your mobile phone carrier to change the account pass-word they ask for when you (or anyone else tries) to manage your account. You should also call them about changing the 4-digit PIN code that can be used to access your voice mail. You should also ask your phone company if they are able to flag your account to lock out any changes or to flag it for higher security should anyone call in to manage it (which would include you).

These are the three biggest potential weak links that cover about 99% of the most likely ways you could be getting hacked. It's also worth taking note than none of these relate to your Apple ID account or to your Apple hardware device.

You’re welcome. If you need any help securing your AppleID, you can also contact Apple support to make sure it’s locked down so only you know everything needed to login to your AppleID.

https://getsupport.apple.com/