How can someone tell if their phone is hacked or being spied on, and what steps should they take to secure it?

Signs your phone may be hacked or spied on

• Battery drains much faster than normal, even when you haven't changed how you use your phone [1][16][43][50].
• Data usage goes up for no clear reason, or your phone bill and charges look higher than usual [2][20][22][43][88].
• Apps appear that you didn't install, or apps start acting strange: opening or closing on their own, taking a long time to load, or crashing [3][15][88].
• Pop-up ads show up outside the apps you're using, and you see unexpected notifications or unrequested two-factor authentication codes [4][19].
• Camera or microphone permissions change, or the camera flash and recording icon turn on by themselves [4][23].
• Your phone slows down, freezes, crashes, restarts, drops calls, or shuts down unexpectedly [14][43][51].
• Online accounts show strange activity like unfamiliar logins, new signups, or password reset emails, or you get locked out of your Apple ID, Google account, or other accounts [5][17][52].
• Call and text logs contain numbers you don't recognize [18][88].
• Websites you normally visit suddenly look distorted, have odd layouts, or redirect you somewhere else [21].
• A phone that has been jailbroken or rooted is less secure and may behave in odd ways [43][75].

How to check for spyware or malware

• Run a scan with a trusted security app. Examples named in the sources include Malwarebytes on iPhone [38], Bitdefender Mobile Security, which can detect even disguised or partially installed spyware [40], and mobile security options from vendors like Avast, F-Secure, Lookout, Sophos, Symantec, and Trend Micro [69]. A good scan can help show whether the phone has actually been hacked and can help remove malware [6][25][55].
• On Android, go to Settings > Apps > See all apps, scroll through the full list, and look for blank spots or apps with generic names like "Cleaner" or "Booster" [30].
• On iPhone, normal scanner apps can't look outside their own app area, so they may miss spyware [31]. Apple's Safety Check feature can review and reset permissions so unwanted people or apps lose access [34].
• One practical reality check for iPhone: if you haven't jailbroken it, nobody has had unsupervised access to your unlocked phone for more than a few minutes, and you're not a high-profile person whose data would be worth hundreds of thousands of dollars to acquire, then spyware is unlikely [33].
• Spyware generally requires physical access to your phone to be installed [32][41].
• If spyware is present, it commonly monitors call history, text messages, contacts, internet browsing, location, photos, and email [42].
• When searching for help or calling for support, use a phone or device you don't think is being monitored [46].

What to do if you think your phone is compromised

1. If you're worried about being tracked or recorded, turn the phone off. Spyware only works while the phone is on and connected, so this temporarily stops GPS tracking and camera or microphone risks [45].
2. Do your research and calls for help on another device you trust [46].
3. Go through your apps and delete anything unfamiliar or suspicious, then restart the phone and check again [9][24].
4. Run antivirus and anti-malware scans [6][25][40][55][89].
5. Change your passwords, starting with iCloud or Google, and do it from a different device. This is one of the most important steps [8][27][36][56][86][90][94].
6. Contact banks, credit card companies, and other financial services. Lock your credit and debit cards and report possible fraud, especially if you use Apple Pay or Google Pay [7][57][92].
7. Warn friends and contacts to ignore or delete any suspicious messages that appear to come from you, because hackers may use your device to send scams [11][28].
8. If the problem continues, do a factory reset. This can remove spyware and malware, but it erases everything on the phone [10][29][35][44][54]. One source says to back up your data first [89], while another says don't restore an old backup afterward so you don't bring the problem back [35].
9. Some detailed guidance suggests calling your carrier to reset the eSIM, resetting the phone, installing the SIM or eSIM again, changing your Apple password and phone passcode, and reinstalling your apps [39].
10. For higher security, consider recovery keys or security keys along with Apple's Lockdown Mode [37]. Also write down hard backup two-factor authentication reset codes in case you get locked out [93].
11. Notify law enforcement if that's appropriate [87].
12. Try to identify likely compromise points so you can close the security gap [95].

Good habits to keep it from happening again

• Keep your operating system and apps updated, ideally with automatic updates, since updates patch security holes [12][65][74][77].
• Turn off Wi-Fi, Bluetooth, AirDrop, and hotspot when you're not using them [13][26][82].
• Use a strong screen lock: a PIN or passcode of at least 6 digits, or face, fingerprint, or pattern unlock [59][60][64][68][79].
• Install apps only from official or trusted app stores. On Android, disable "allow installation from unknown sources" and enable "verify apps" [47][62][78].
• Research an app before downloading it; some apps carry malware or send you to harmful websites [76].
• The most common ways spyware gets on a phone are installing software from shady sites and clicking links in shady emails or messages, so avoid that [48].
• Avoid suspicious links and random apps, and be careful with public Wi-Fi. If you use public Wi-Fi, use a VPN [13][49][58][61][83].
• Back up your phone data regularly so you can recover your information if you need to wipe the phone [63][66][73].
• Enable a "Find My"-style feature so you can locate, lock, or erase your phone remotely [67][71][81][85].
• Use encryption if it's available; it protects your data from someone who gets physical access to the phone [70][80].
• Don't jailbreak or root your phone, because that makes it much easier to attack [75].
• Don't reuse passwords across accounts, and use strong passwords plus two-factor authentication [49][84].
• Remove apps and services you don't need, because fewer extras means fewer ways in [72].
• Be careful with public charging stations as well as public Wi-Fi [13].