Eh, more likely than not, these days. Anywhere you leave your phone number, there will be folks who’ll try hacking into people’s phones out of mere boredom. For fun. Or to store files on that they don’t want others to see. Hacking is a largely risk-free crime. Unless you hack into the Pentagon or steal really large sums of money, it doesn’t matter what you do, in practice, because it is such a hard crime to investigate and tackle.

Norton says the following. 

(Italics = my words)

If your phone is displaying one of the following unusual behaviors, and especially if it’s displaying more than one, there’s a good chance that it may be hacked. 

1. Strange or inappropriate pop-ups:

One apparent sign of a hacked phone is nonstop pop-ups. Bright, flashing ads or X-rated content popping up on  your phone is a big indicator that your phone has been compromised. (Note: They can also be innocent-looking.)  

2. Texts or calls not made by you

As the owner of your device, you likely remember every time you use your phone throughout the day. So, if you  notice texts or calls from your phone that you didn’t make, you may have had your phone hacked.   

3. Higher than normal data usage

There are many reasons for high data usage (for example, increased use of a new app). But if your phone behavior  has stayed the same and your data usage has skyrocketed, it’s time to investigate.  

4. Apps you don’t recognize on your phone

Keep in mind that new phones often come with pre-downloaded apps. But if you notice new apps popping up  once you already own the phone, there may be malware involved.  (Note: This is almost impossible to check on Androids nowadays because Google installs so much crap.)

5. Battery draining quickly

Phone batteries aren’t meant to last forever, but they’re also designed efficiently. So, if your phone use habits have  remained the same, but your battery is draining more quickly than normal, hacking may be to blame. (This tends to include that the phone gets HOT.) 

Reset your phone

The majority (=not all!) of malware can be removed with a factory reset of your phone. This will, however, wipe any data  stored on your device, such as photos, notes, and contacts, so it’s important to back up this data before resetting  your device. Follow the instructions below to reset your iPhone or Android.  

Instructions for resetting an iPhone

1. If you have a Mac with macOS Catalina 10.15, open Finder. Otherwise, open iTunes. 
2. Connect your iPhone to your computer. 
3. Select your device on your computer. 
4. Select “Restore iPhone.” 

For more detailed instructions, visit Apple support. 

Instructions for resetting an Android phone

1. Android reset instructions vary by manufacturer. You should visit your phone manufacturer’s website for specific instructions. 
2. For most Android phones, you can access the reset option via your Settings menu, or by holding down the  power and volume buttons.  

For more detailed instructions, visit Google support. 

Change your passwords

It’s possible that your login credentials were compromised when your phone was hacked. Once you’ve removed  the malware, reset all of your passwords and create unique passwords for each account. (Tip: write them down on index cards if you find it hard to have many different passwords. My locks get picked all the time, but yours likely are not so your index cards should be safe.) 

Does resetting your phone get rid of viruses? 

Yes, a factory reset is one way to potentially remove a virus from an infected mobile device. 

Why do hackers hack your phone? 

Hackers compromise smartphones to access the personal information stored on each device, oftentimes  exploiting and/or selling what they get their hands on. (Note: They can also do this for fun, out of boredom, in the hope to find compromising or silly photos or videos, just for a laugh, or to mess with you.)

Does turning off your phone stop hackers? 

Yes, turning off your phone can stop hackers, as most cyberattacks targeting cell phones require the device to be  turned on. (Note: Your phone can still be detected though, if the battery is still in it, even if there is no SIM card in it.)

Can hackers hear you? 

Yes, hackers may be able to hear you if they’ve gained access to your phone’s camera and microphone. (Note: This is probably often the first thing that they do.) 

Does airplane mode block hackers? 

Turning on airplane mode can temporarily block hackers while the device is not connected to Wi-Fi or a cellular network.

What can a hacker do with your phone number? 

Hackers often compromise phone numbers in order to: 

• Verify 2FA requests 
• Send malicious links 
• Complete vishing attacks
• Clone your phone
• Redirect outgoing calls and texts (possibly also as part of vishing)
• Block access to the nearest cell phone tower to force you to go somewhere else (this may be called “jamming” – it’s happened to me here in Portsmouth)
• Spy on you (exes, stalkers, jealous partners, parents)
• Record your voice (to use in voice-cloning)
• Look at your contacts (and your communications) so that they can contact them (text, e-mail, voice-cloning), pretend to be you and for example ask for money (or high-jack e-mail conversations with suppliers or clients)
• Steal video or image files (for revenge porn or deepfakes)

Can someone hack your phone and turn on your camera? 

Yes, cybercriminals can hack phones to gain access to their cameras. (Note: This is probably often the first thing that they do.) 

https://us.norton.com/blog/malware/is-my-phone-hacked#