Is your phone hacked? How to tell and what to do

Phones today include strong security protections, but no phone is impossible to compromise. Current iPhones and supported Android phones both use safeguards such as app isolation, secure startup processes and built-in protections against malicious software. Your level of protection also depends on how quickly your phone receives updates, where you install apps from and which security settings you use.

In rare cases, highly sophisticated mercenary spyware can exploit previously unknown software flaws and infect a phone without the owner clicking anything. Pegasus is one well-known example. These attacks require extensive resources and generally target a very small number of journalists, activists, government officials and other high-profile individuals. For most of you, phishing, stolen passwords, malicious apps, carrier account fraud or someone gaining physical access to the phone are more likely concerns.

We received an email from Joyce in Corbin, Kentucky, who wrote:

“I have a family member whose phone has been taken over by someone. It controls her phone at times, so she can’t call. She can only text, not call. How do they take control of your phone? And what can you do?”

That would be frightening, but those symptoms alone do not confirm that someone hacked the phone. A person may still be able to send messages through Wi-Fi while cellular calling fails because of a carrier outage, SIM or eSIM problem, account restriction or unauthorized change to the wireless account. The first step should be contacting the carrier from another trusted phone and asking it to check for unexpected SIM changes, number transfers and account activity.

Common ways your phone can be hacked and how it happens

You do not need spy-grade technology to compromise a phone. Many incidents begin with a convincing message, a stolen password, an unsafe app or physical access to the device.

Phishing messages and calls

Phishing is one of the most common methods. This usually involves receiving a fake text, email or even a phone call designed to trick you into clicking a malicious link or sharing sensitive information. It could look like a message from your bank, a delivery service or even a friend. The goal may be to steal your password, persuade you to install an app or convince you to reveal a one-time verification code. A legitimate company will not unexpectedly contact you and ask you to read back a security code sent to your phone.

SIM swapping and number porting

SIM-swapping is another major threat. In this scam, someone convinces your phone provider to move your number to their SIM card. Once they gain control, they can read your texts, take calls and access accounts that rely on your number. A sudden loss of cellular service can be a warning sign, especially when other phones on the same carrier are working normally. However, service loss can also result from an outage or technical problem, so contact the carrier immediately rather than assuming the phone was hacked.

Malicious apps and stalkerware

Malicious apps are also a big risk, especially on devices where users sideload apps or install them from unofficial sources. Some apps appear harmless but are designed to spy on your activity, steal data or give remote access to an attacker. Harmful apps have occasionally reached official app stores as well. Stalkerware is another concern, particularly when someone has had physical access to your unlocked phone. It may track your location, read messages or collect other activity without your knowledge.

Stolen passwords and compromised accounts

Sometimes the phone itself remains secure, but an attacker signs in to your Apple, Google, email, messaging or social media account. That can allow the attacker to read synchronized information, impersonate you or change account settings without installing malware on your phone.

Remote-support apps and management profiles

A scammer may persuade you to install a remote-support app or grant powerful accessibility, screen-sharing or device-management permissions. These tools can be legitimate when used by a trusted employer or technician, but dangerous when controlled by a scammer.

Public Wi-Fi and Bluetooth

Public Wi-Fi deserves caution, but the risk should not be overstated. Because most websites and apps now encrypt their traffic, connecting through public Wi-Fi is generally safer than it once was. You should still confirm the network name, avoid unexpected login pages and make sure websites use HTTPS. A VPN can add another layer of privacy when you do not trust the network. Bluetooth attacks are possible, but they are far less common than phishing, stolen passwords and unsafe apps. Keep your phone updated and turn off Bluetooth when you are not using it, particularly in crowded public areas.

Signs your phone has been hacked and what may be a false alarm

Not every glitch or slowdown on your phone means you’ve been hacked. Sometimes, it’s just a buggy app, a bad update or your phone running low on storage. Battery drain, overheating, slow performance and higher data use can accompany malicious software, but none of those symptoms proves that a phone has been hacked. Background noise during a call is also not a reliable sign of spying.

Stronger warning signs include:

• Messages, calls or social media posts you did not create
• Apps or configuration profiles you do not recognize
• Passwords, recovery details or security settings changing without your permission
• Unknown devices signed in to your Apple, Google or other important accounts
• Your carrier confirming an unauthorized SIM or eSIM change
• Losing cellular service while other nearby phones on the same carrier continue working
• Contacts receiving messages from your accounts that you did not send
• Unexpected changes to accessibility, device-administrator, call-forwarding or sharing settings

If you are locked out of accounts linked to your number or your mobile service suddenly stops working, it could point to SIM swapping. However, you should contact your carrier to confirm what happened.

What to do if you think someone controls your phone

If you cannot make calls or your cellular service suddenly disappears, use another trusted phone to contact your wireless provider. Ask whether your SIM, eSIM, account password, authorized users or number-porting settings were changed.

Next, use a trusted device to secure your primary email account, Apple Account or Google Account. Your email often controls password recovery for your other accounts, so protect it first. Change the password, review your recovery information and sign out devices you do not recognize.

If you suspect that a partner, former partner or family member installed monitoring software, think about your physical safety before removing apps, changing settings or resetting the phone. Those actions may alert the person doing the monitoring. Use a separate trusted device to seek assistance and preserve possible evidence before making changes.

How you can protect your phone from hackers

Want to keep your phone safe from hackers? Follow these essential steps to protect your device, your data and your privacy.

1) Secure your most important accounts from a trusted device

One of the first things to do if you suspect your phone has been compromised is to change your passwords, especially for critical accounts like email, banking and social media. Make sure your new passwords are strong and unique. Consider using a reputable password manager to create and store complex passwords without the headache of remembering them all.

Start with your primary email, Apple Account or Google Account because those accounts often control password recovery for everything else. Review the devices signed in to each account and remove anything you do not recognize. Also check whether anyone changed your recovery email address, phone number or security methods.

2) Be wary of potential phishing attacks and use security software appropriately

Phishing attacks try to trick you into revealing sensitive information by pretending to be trustworthy sources like banks or friends. Always double-check the sender’s email address or phone number before clicking links or downloading attachments.

Instead of opening a link in an unexpected message, open the company’s official app or type its known website address yourself. Never share a one-time verification code with someone who unexpectedly contacts you.

Security software can provide malicious-site warnings, scam protection and other useful features. However, its abilities differ between iPhone and Android.

On Android, Google Play Protect already scans apps for potentially harmful behavior. A reputable security app may add web protection, identity alerts and other tools.

On an iPhone, third-party apps are isolated from other apps and system files. That means an iPhone security app cannot scan the entire phone in the same way antivirus software scans a Windows computer. It may still help identify dangerous websites, suspicious messages, unsafe networks or exposed account information.

No consumer security app can guarantee that it will detect highly sophisticated mercenary spyware.

3) Update your device

Regularly updating your phone’s operating system and apps is crucial for security. Developers release updates not only to add new features but also to patch security flaws that hackers can exploit. Ignoring updates leaves your device vulnerable to attacks, so make it a habit to install them as soon as they become available.

Also confirm that your phone still receives security updates. An older device that no longer receives patches may need to be replaced.

4) Enable two-factor authentication

Two-factor authentication (2FA) is one of the simplest and most effective ways to protect your accounts. With 2FA enabled, logging in requires two steps: your password plus a second verification method.

Whenever an account supports them, a passkey, authenticator app, trusted-device prompt or physical security key generally provides stronger protection against phishing and SIM swapping than a code sent by text message.

An SMS code is still better than using only a password when no stronger option is available. Never give a verification code to someone who calls, texts or emails you asking for it.

5) Use public Wi-Fi networks carefully

Public Wi-Fi is not automatically unsafe because most modern websites and apps encrypt traffic. Still, confirm the correct network name before connecting and be cautious if a network unexpectedly asks you to install software, enter payment information or sign in with an email or social media password.

Look for HTTPS when using a browser. A virtual private network can encrypt the connection between your device and the VPN provider, adding privacy when you are using a network you do not control.

6) Protect your wireless account and lock your SIM

Contact your mobile provider and set up a PIN or port-out protection for your account. This prevents scammers from transferring your number without your permission, a key defense against SIM swapping.

Ask whether your provider offers a number lock, port freeze, SIM protection or another safeguard that blocks unauthorized transfers.

You can also enable a SIM PIN on many iPhones and Android phones. A SIM PIN prevents someone from using the SIM or eSIM after the phone restarts or the SIM is moved. It is different from your carrier account PIN and does not replace carrier-level number-transfer protection.

Do not guess the default SIM PIN. Entering the wrong PIN repeatedly can lock the SIM and require a carrier-provided PUK code.

7) Remove suspicious apps, profiles and powerful permissions

Take time to review all the apps installed on your phone. Uninstall anything you don’t recognize, no longer use or that seems suspicious.

Pay particular attention to apps with access to accessibility controls, device administration, notifications, location, the microphone, the camera or screen sharing.

On Android, open the Google Play Store, tap your profile icon and select Play Protect to check for harmful apps. Also review apps with device-administrator and accessibility access in Settings. Menu names can vary by phone manufacturer.

On an iPhone, open Settings > Privacy & Security > Safety Check to review sharing, connected devices and account access. You should also open Settings > General > VPN & Device Management and look for profiles you do not recognize.

Do not remove a legitimate work or school management profile before checking with the organization that manages the phone.

8) Use a strong screen lock and theft protection

Protect your phone with a strong passcode and biometric authentication. Avoid easy-to-guess codes such as birthdays, repeated digits or the last four digits of your phone number.

On an iPhone, consider turning on Stolen Device Protection. It adds biometric checks and security delays for sensitive changes when the phone is away from familiar locations.

Android theft-protection features vary by phone, but supported devices may include Theft Detection Lock, Offline Device Lock, Remote Lock and Identity Check. Search for “theft protection” in your phone’s Settings app to review the options available on your device.

9) Use a personal data removal service

A personal data removal service cannot remove malware, regain control of your phone or secure a compromised account. Its role is separate from phone recovery.

If your phone has been compromised, it’s possible that your personal information, like your name, address, phone number or email, is already being shared or sold online. Hackers often collect this data to commit identity theft or launch targeted phishing attacks. A personal data removal service can scan data broker sites and request that your information be deleted, reducing the amount of information scammers can easily find.

While no service can guarantee the complete removal of your data from the internet, these services can submit removal requests to participating data brokers and repeat those requests when information reappears. By limiting the information available, you can make it more difficult for scammers to combine breach data with details found on data broker sites.

10) Factory reset your device as a last resort

If your phone continues to act strangely after you’ve tried other fixes, a factory reset on your iPhone or Android might be necessary. This process erases all data and settings, giving you a fresh start. Before doing this, back up your important files, photos and contacts because a factory reset will delete everything on your device. A factory reset removes most ordinary malicious apps and stalkerware. After the reset, install the latest operating-system updates before adding apps. Reinstall apps only from trusted sources and avoid restoring questionable apps or settings from an old backup.

A reset will not fix a compromised email account, stolen password, unauthorized SIM transfer or carrier account problem. You must secure those separately. If Apple sends you a threat notification warning that mercenary spyware may have targeted you, take it seriously. Follow Apple’s instructions, seek qualified cybersecurity assistance and consider turning on Lockdown Mode, which Apple designed for the small number of individuals facing highly targeted attacks.

Related Links: 

• Apple AI security update proves hackers move fast
• Should you change your phone number after a hack?
• Russian hackers hijacked old Wi-Fi routers

Kurt’s key takeaway

A phone that behaves strangely has not necessarily been hacked. Calling problems, battery drain and glitches can have ordinary explanations. However, unexpected account changes, unknown apps, unauthorized messages or a sudden loss of cellular service deserve immediate attention. For most of you, the greatest risks come from phishing, stolen passwords, malicious apps and carrier account fraud rather than spy-grade attacks. Protect your primary email, keep your phone updated, review powerful app permissions and secure your wireless account before trouble starts.

Should phone companies be doing more to stop these kinds of attacks, or is it all on us? Let us know in the comments below.

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