Can Apple devices be hacked/compromised?

With enough time, money and expertise, anything can be compromised. By "enough money" I mean $500,000 to a million dollars. Generally, this type of hacking is done by state actors. In my opinion (IANAL), your attorney is either paranoid or completely unfamiliar with Apple produces or both.

What could be at issue is your Apple Account. That would be an easier target,

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

If your attorney remains convinced that your devices have been compromised, the obvious answer is to stop using them for this project. Use a burner phone for calls and use the postal service for sending documents. Leave all devices outside of the room, preferable in a faraday bag, during meetings. 

Yes, Apple devices can be hacked or compromised despite their strong security reputation. Given your high-stakes legal situation, if confidential details are being leaked, it is crucial to act immediately. Apple devices can be targeted through advanced spyware, phishing attacks, compromised iCloud accounts, rogue apps, or network vulnerabilities. To secure your devices, start by changing all passwords, especially for your Apple ID, email, and any sensitive accounts. Enable two-factor authentication (2FA) on all accounts to add an extra layer of protection. Next, check for spyware by reviewing your device’s analytics logs under Settings → Privacy & Security → Analytics & Improvements. Also, verify your Apple ID for any unknown devices by going to Settings → Apple ID → Devices and remove any unauthorized access. Review installed profiles under Settings → General → VPN & Device Management and delete any that seem suspicious. Keeping your devices updated is essential, as Apple frequently releases security patches to prevent vulnerabilities. Additionally, secure your home network by changing your Wi-Fi password and ensuring your router uses WPA3 encryption. If you suspect your devices are still compromised, consider performing a factory reset by erasing all content and settings after backing up your important data. As an extra precaution, avoid discussing sensitive matters over calls or messages and use encrypted communication apps like Signal. If the issue persists, consulting a cybersecurity expert is advisable to thoroughly inspect your devices.

[Edited by Moderator]

GMSSUK wrote:

To secure your devices, start by changing all passwords, especially for your Apple ID, email, and any sensitive accounts. Enable two-factor authentication (2FA) on all accounts to add an extra layer of protection.

Good advice

Next, check for spyware by reviewing your device’s analytics logs under Settings → Privacy & Security → Analytics & Improvements. Also, verify your Apple ID for any unknown devices by going to Settings → Apple ID → Devices and remove any unauthorized access. Review installed profiles under Settings → General → VPN & Device Management and delete any that seem suspicious.

Not so good advice. Without the specialized training and software that Apple engineers have, pretty much everything in Analytics looks suspicious. It's a rabbit hole that leads to .... a great steaming pile of rabbit droppings.

Keeping your devices updated is essential, as Apple frequently releases security patches to prevent vulnerabilities.

Excellent advice.

Note that iMessages is end-to-end encrypted.

Every system of any significant size has bugs in it. If you're looking for mathematical proof that it is impossible for anyone to have hacked your devices, you are not going to find it here.

However, unless the bad actor targeting you is someone like Vladimir Putin or Kim Jong Un, who has the resources of an entire country at their disposal, you probably are not being hacked. It seems much more likely that you have compromised your own security in some way, e.g., by

• Allowing an adversary to have physical access to your devices
• Failing to use passcodes and passwords that an adversary does not know and cannot guess
• Falling for "phishing" messages aimed at getting you to disclose your credentials

Analogy: If you leave the key to your house inserted in the lock to your front door, it does not matter how good the lock is, or whether it's a metal door, or whether the frame is a metal frame. All the bad guy has to do it is to see the key, use the key, and walk right in.