iPhone audio recording by itself

You may have a bad digitizer.

First, try a forced restart. If that doesn't work take it in to the Apple store to have it looked at.

• Press and quickly release the volume up button

• Press and quickly release the volume down button

• Press and hold the side button.

• When the Apple logo appears, release the button.

Force restart iPhone - Apple Support (IN)

Make an appointment at the Genius Bar to have it diagnosed.

Genius Bar Reservation and Apple Support Options - Apple

While smartphones themselves can't harbor malicious intent, we must actively fortify their defenses. Tighten your device settings, be mindful of how you sync, and protect your digital treasure trove by safeguarding sensitive information with your loved ones. Don't underestimate the power of simple security measures. Employ strong passwords, enable two-factor authentication, and regularly update software.

 However, the vulnerabilities lie in our usage and connectivity. Unsecured settings, careless syncing, and oversharing sensitive information can transform this innocuous device into a Trojan horse for attackers. Vigilance is key.

If you feel an unauthorized person/app is remotely using, controlling or monitoring your device, then that is possible only if you have done one or more of the following Don'ts...

1. Don't hand over an iPhone to kids or to a stranger without Enabling Guided Access
2. Don't share Apple IDs
3. Don't Jailbreak
4. Don't share sensitive information pertaining to your device
5. Don't give in to Phishing
6. Don't plug in your device in Airports and Public places through third-party cables and trust the device. Beware of Juice Jacking. (Especially in India)
7. Don't leave your iPhone unlocked and unattended in public places like offices, schools, malls, etc.

If one of the above is true then quickly change the Apple ID Password and Return iPhone settings to their defaults.