Your phone holds access to your bank accounts, private messages, photos, and countless personal details. When hackers gain control of this device, they can steal money, impersonate you, or expose sensitive information. The main signs your phone is hacked include unusually fast battery drain, unexpected data usage spikes, unfamiliar apps appearing on your device, strange pop-ups, and being locked out of your accounts.
Most people don’t realize their phone has been compromised until significant damage occurs. Both iPhones and Android devices face threats from malicious links, fake apps, and SIM swap attacks that transfer your number to a hacker’s control. The good news is that specific symptoms reveal when something is wrong.
Last Updated: May 2026 | Will Montgomery has spent years evaluating mobile security tools and phone privacy practices. He’s personally gone through the process of securing compromised devices and knows firsthand what warning signs matter most.
This guide walks through the warning signs that indicate a hack, how to check your device settings and app behavior, and what steps to take immediately if you suspect your phone has been compromised. It also covers practical ways to protect your device from future attacks.
Common Warning Signs of Phone Hacking
A hacked phone often shows clear warning signs that something is wrong. These signs range from battery problems and unfamiliar apps to unusual data usage and suspicious account activity.
Sudden Battery Drain or Overheating
A phone that suddenly drains its battery much faster than normal may be running hidden malware or spyware in the background. These malicious programs work constantly to collect data or send information to hackers, which uses up battery power quickly.
The phone may also feel warm or hot to the touch even when not in active use. This happens because hacking software forces the processor to work harder than usual.
Normal battery degradation happens slowly over months or years. A sudden change in battery life over just a few days or weeks signals a potential problem. Common warning signs of phone hacking include unusual battery drain and overheating issues.
Users should check their battery usage in settings to see which apps consume the most power. Unknown apps using significant battery power indicate a security issue.
Unfamiliar Apps or Activity
Apps that appear on the phone without being downloaded are major red flags. Hackers install malicious software to gain access to personal information, track location, or control the device remotely.
The phone may also show signs of activity when no one is using it. The screen might light up, apps may open by themselves, or settings could change without permission. Pop-up ads that appear frequently, especially outside of web browsers, suggest malware infection on the device.
Users should regularly review their installed apps and remove anything they don’t recognize. Some malicious apps disguise themselves with generic names or icons that look like system files. Checking app permissions also helps identify programs with suspicious access to contacts, messages, or the camera.
Unexpected Data Usage Spikes
A sudden increase in data usage without any change in phone habits often means malware is sending information in the background. Hacking software transmits stolen data, records conversations, or communicates with remote servers, all of which consume cellular data or WiFi bandwidth.
Users can check their data usage through phone settings to see which apps use the most data. Unknown apps or system processes using large amounts of data need immediate attention.
High data usage is a telltale sign that the phone may be compromised. Even on unlimited plans, carriers often notify users about unusual data consumption patterns.
Some phones allow users to set data limits or restrict background data for specific apps. These features help identify suspicious activity more quickly.
Strange Calls, Texts, or Account Changes
Friends or contacts may report receiving strange messages or calls that the phone owner never sent. Hackers use compromised phones to spread malware to other devices or conduct phishing attacks on the victim’s contact list.
The phone bill might show calls or texts to unfamiliar numbers, especially premium-rate numbers or international destinations. Bank accounts, email, or social media accounts may show login attempts from unknown locations.
Users might get locked out of their own accounts if hackers change passwords. Warning signs of a hacked phone include these types of unauthorized account activities.
Two-factor authentication codes arriving without requesting them suggest someone is trying to access accounts. Any notification about password changes or security settings that the user didn’t initiate requires immediate action.
Investigating Unauthorized App Behavior
Apps on a phone should only perform the functions they were designed for, but malicious software often operates differently. Checking which apps are installed and what permissions they have access to helps identify potential security threats.
Reviewing Installed Apps for Suspicious Software
The first step involves examining all installed applications on the device. Users should open their phone’s settings and navigate to the apps section to see a complete list of what’s currently installed.
Finding apps that were not personally downloaded can indicate unauthorized access to the device. These unfamiliar programs may appear with generic names or icons that blend in with legitimate software.
Apps that behave strangely also warrant investigation. This includes programs that crash frequently, open on their own, or consume excessive battery power and data. Users should delete any application they don’t recognize or remember installing.
It’s important to note that some malware disguises itself as system apps. Any application requesting unusual permissions for its stated purpose should be removed immediately.
Understanding iPhone App Permissions
iPhone users can control what information and features each app can access through the Settings menu. Apps commonly request permissions for location services, camera, microphone, contacts, and photos.
Each permission request should align with the app’s actual function. A basic calculator app requesting microphone access, for example, raises red flags. Users should tap on Privacy & Security in Settings to review all permission categories.
The system displays which apps have requested each type of access and whether the permission was granted. Revoking unnecessary permissions strengthens device security. Apps that require extensive permissions to function properly deserve extra scrutiny before installation.
Using the App Privacy Report on iPhone
The App Privacy Report provides detailed insights into how apps use granted permissions over time. iPhone users can enable this feature by going to Settings, selecting Privacy & Security, and turning on the App Privacy Report.
Once activated, the report tracks which apps accessed sensitive data like location, camera, or contacts during the past seven days. It also shows what websites apps connected to and which domains they contacted most frequently.
This information helps identify apps that access data more often than expected. An app checking location hundreds of times per day when it shouldn’t need constant tracking indicates suspicious behavior. The report also reveals if apps are sharing data with third-party services without clear justification.
Analyzing iOS Privacy and Security Settings
iOS includes built-in privacy controls that help users limit what apps can access and track. Disabling precise location and reviewing which apps use your camera and microphone can reduce potential security risks if your phone is compromised.
Navigating iOS Privacy Settings
Users can access privacy controls by opening the Settings app and tapping on Privacy & Security. This menu displays all permission categories including Location Services, Camera, Microphone, Contacts, Photos, and more.
Each category shows which apps have requested access. Tapping on any category reveals a list of apps with their current permission status. Apps typically have options like “Never,” “Ask Next Time,” or “Allow” depending on the feature.
The App Privacy Report provides detailed information about how apps access data and sensors. Users can enable this feature in Privacy & Security settings to track which apps access location, camera, microphone, and other sensors over time.
Reviewing these settings regularly helps identify apps with excessive permissions. Users should revoke access for apps that don’t need certain permissions to function properly.
Disable Precise Location on iPhone
Location Services can be found under Privacy & Security in the Settings app. Users can toggle off Location Services entirely or customize settings for individual apps.
Most apps offer two location permission levels: “While Using the App” and “Always.” The “Always” option lets apps track location even when closed. Users should select “While Using the App” for most applications.
iOS also includes a Precise Location toggle for each app. When disabled, apps receive only an approximate location within several miles rather than exact coordinates. This feature works well for weather apps, shopping apps, and other services that don’t require pinpoint accuracy.
Users can disable Precise Location by selecting an app in Location Services and turning off the Precise Location switch. This reduces tracking while maintaining basic functionality.
Manage Camera and Microphone Access
The Camera and Microphone sections under Privacy & Security list all apps with access to these features. Users should verify that only trusted apps like video calling services and social media platforms have these permissions.
Suspicious or unfamiliar apps with camera or microphone access could indicate spyware or monitoring software. Users should immediately revoke permissions for any unrecognized apps.
iOS displays an orange dot at the top of the screen when the microphone is active. A green dot appears when the camera is in use. These indicators help users identify when apps access these features without permission.
Users can also review recent camera and microphone usage through the App Privacy Report. This shows which apps accessed these sensors and when, making it easier to spot unauthorized activity.
Monitoring Background and Network Activity
Apps running in the background and unusual network traffic can reveal if someone has compromised a phone. These activities drain resources and send data without the user’s knowledge.
Checking Background App Refresh Settings
Background App Refresh allows apps to update content when not in active use. On an iPhone, this setting lets apps pull new data even when closed. Hackers exploit this feature by hiding spyware that runs constantly in the background.
Users should review which apps have background permissions enabled. On iPhone, they can navigate to Settings > General > Background App Refresh. They should look for unfamiliar apps or apps that don’t need this feature turned on.
Apps like calculators or flashlights don’t need background refresh. If these basic tools have the setting enabled, it raises a red flag. Users should disable background refresh for any suspicious or unrecognized apps immediately.
Android users can check similar settings under Settings > Apps > Special Access > Optimize Battery Usage. They should look for apps running when they shouldn’t be.
Observing High Network Usage and Pop-Ups
Spyware transmits stolen information from the phone to hackers, which causes data usage to spike. Users should check their data consumption regularly through their phone’s settings. Unexpected increases often indicate malicious activity.
On iPhone, they can view data usage under Settings > Cellular or Mobile Data. On Android, the path is Settings > Network & Internet > Data Usage. Users should look for apps consuming large amounts of data despite limited use.
Pop-up ads appearing outside of web browsers signal adware or malware infections. These pop-ups might appear on the home screen or while using other apps. If websites look different than usual, malware might be redirecting the browser to fake copies designed to steal login credentials.
Users who notice excessive pop-ups should avoid clicking on them. They should close the browser completely and scan their device for malicious software.
Account and Financial Security Red Flags
Hackers often target phones to access sensitive accounts and financial information. Unauthorized charges and locked accounts are two of the clearest signs that someone has compromised a device.
From experience: A SIM swap attack can escalate faster than you’d expect. The first sign was a strange text that seemed ignorable — until sign-in attempt notifications started hitting crypto accounts and passwords had already been changed. The attackers worked their way from phone number to email to iCloud, eventually factory resetting every device on the account. Recovery took over three months. The hardest part: the attackers had quietly set up email forwarding rules inside the account to intercept messages from the crypto platform, rerouting them without a trace — something that went undetected until well after the breach.
Detecting Account Takeovers
A hacked phone can give attackers direct access to email, social media, and other online accounts. Users may notice they cannot log into accounts they previously accessed without issue. Password reset emails that arrive unexpectedly indicate someone is attempting to take over accounts.
Friends or contacts might report receiving strange messages or friend requests that the user never sent. New posts, comments, or activity on social media accounts that the account holder did not create are major warning signs. Email accounts might show sent messages the user never wrote.
Account settings may change without the user’s knowledge. This includes updated recovery email addresses, phone numbers, or security questions. Some users discover new devices or login locations listed in their account activity that they do not recognize.
Spotting Unusual Financial Activity
Unexplained charges on bank accounts or credit cards often indicate hackers have stolen financial information from a compromised phone. Small test charges may appear first before larger fraudulent transactions occur.
Users should check for unauthorized purchases on payment apps like PayPal, Venmo, or Apple Pay. Subscription services the user never signed up for are another red flag. Bank statements might show withdrawals or transfers the account holder did not authorize.
Credit card companies may send fraud alerts about suspicious purchases. Users who receive these alerts should take them seriously and investigate immediately. Monitoring financial accounts regularly helps catch unauthorized activity quickly before significant damage occurs.
Responding to Suspected Hack Attempts
Acting quickly when a phone hack is suspected can limit damage to personal accounts and data. The key steps involve securing all passwords, eliminating suspicious software, and determining whether a full device reset is necessary.
Changing Passwords Securely
Password changes should happen immediately after detecting signs of a hack. Users need to change passwords for all accounts connected to the compromised phone, starting with banking apps, email accounts, and social media platforms.
The new passwords must be strong and unique for each account. A strong password contains at least 12 characters with a mix of uppercase letters, lowercase letters, numbers, and symbols. Avoid using common words, birthdays, or personal information that hackers can easily guess.
Password changes should occur on a different device if possible. Using the hacked phone to change passwords might allow the attacker to capture the new credentials. A separate computer or tablet provides a safer environment for this task.
Two-factor authentication adds another layer of protection. Enabling this feature on all important accounts means hackers need more than just a password to access them. Users should change all passwords immediately after discovering a breach.
Removing Malicious Apps and Profiles
A complete audit of installed apps helps identify suspicious software. Users should look through their app list and delete anything they don’t recognize or didn’t intentionally download. Malicious apps often have vague names or appear similar to legitimate applications.
Some dangerous apps hide themselves or reinstall after deletion. If an app keeps reappearing, the phone likely has deeper malware issues that require antivirus software. Reputable security programs can find and remove malware or spyware that standard deletion methods miss.
Settings profiles also need checking, especially on iPhones. Hackers sometimes install configuration profiles that give them access to phone data. Users can check for these in Settings under General or Profiles & Device Management.
Third-party app stores increase security risks. Sticking to Google Play Store or Apple’s App Store reduces the chance of downloading infected apps in the future.
When to Reset Your Device
A factory reset becomes necessary when other methods fail to remove malicious software. This option erases everything on the device and returns it to its original state. Users should back up important photos, contacts, and files before proceeding.
Signs that a reset is needed include persistent pop-ups, apps that keep reinstalling themselves, or ongoing unusual behavior after removing suspicious apps. Restoring a phone to factory settings serves as the nuclear option when dealing with severe infections.
The reset process varies by device. iPhone users go to Settings > General > Transfer or Reset iPhone, while Android users find the option under Settings > System > Reset options. The phone should be fully charged before starting this process.
After completing the reset, users must reinstall apps carefully. Only download essential applications from official stores and restore data from clean backups created before the hack occurred.
Best Practices for Future Protection
Installing security software and keeping all updates current forms the foundation of phone protection. Strong passwords, careful app selection, and regular privacy audits create multiple layers of defense against hackers.
Safe App Downloads and Updates
Users should only download apps from official stores like Google Play or the Apple App Store. Third-party app stores often host malicious software disguised as legitimate applications.
Before downloading any app, users need to check ratings and read recent reviews. Apps with few downloads, poor ratings, or complaints about suspicious behavior should be avoided. Checking the developer’s name and verifying it matches the official company helps prevent fake app downloads.
Key steps for safe downloads:
- Review app permissions before installing
- Avoid apps requesting unnecessary access to contacts, location, or files
- Delete unused apps regularly
- Enable automatic updates for security patches
Software updates fix known vulnerabilities that hackers exploit. Users should install operating system updates as soon as they become available. Delaying updates leaves phones exposed to threats that have already been patched.
Enabling Security Features on iPhone
iPhone users should enable Find My iPhone through Settings > Apple ID > Find My. This feature allows remote device location and data wiping if the phone is lost or stolen.
Two-factor authentication adds critical protection to Apple ID accounts. Users can activate this under Settings > Apple ID > Sign-In & Security. This requires a second verification step when logging in from new devices.
Face ID or Touch ID should be enabled with a strong passcode backup. Users can set this up in Settings > Face ID & Passcode. The passcode should be at least six digits and avoid obvious patterns.
Additional iPhone security settings:
- Turn on automatic iOS updates
- Enable “Erase Data” to wipe phone after 10 failed passcode attempts
- Disable lock screen notifications for sensitive apps
- Use Screen Time to restrict app installations
Encrypting iPhone backups through iTunes or Finder adds another protection layer for stored data.
Routine Privacy Check-Ups
Users should review installed apps monthly and remove anything unfamiliar or unused. Suspicious apps can appear unexpectedly when phones are compromised.
Checking app permissions quarterly ensures programs only access necessary data. Both iPhone and Android allow users to view which apps access location, camera, microphone, and contacts. Revoking unnecessary permissions reduces risk.
Bank statements and phone bills need regular monitoring for unauthorized charges. Unexpected data usage spikes or unfamiliar transactions indicate possible compromise.
Password changes every three to six months help protect accounts even if credentials leak. Users should create unique passwords for each account and store them in a password manager. Reusing passwords across multiple sites lets hackers access all accounts if one is breached.
Bluetooth and WiFi should be turned off when not in use. Public WiFi networks pose particular risks. Users connecting to public networks should use a virtual private network (VPN) to encrypt their data transmission.
Frequently Asked Questions
Phone hacking can happen to anyone, and knowing what to look for helps protect personal data and financial accounts. These questions address the most common concerns about detecting and responding to unauthorized access.
What are the most common warning signs that a smartphone has been compromised?
A fast-draining battery is one of the first indicators something is wrong. The phone may also feel hot even when not in heavy use.
Unexpected data usage spikes appear on phone bills when malware sends information in the background. Apps may open or close on their own without any user input.
Pop-ups and notifications that seem unfamiliar can indicate suspicious behavior on a hacked device. The phone might also slow down significantly or take longer to load basic functions.
Users may notice apps they never downloaded appearing on their home screen. Settings like camera or microphone permissions might change without explanation.
How can I check my iPhone for signs of unauthorized access or spyware?
iPhone users should review all installed apps in Settings to identify anything unfamiliar. Legitimate apps only come from the official App Store in most cases.
Check battery usage in Settings to see which apps consume the most power. Any unknown app using significant battery could be malicious.
Review privacy settings to see which apps have access to location, camera, microphone, and contacts. Revoke permissions for any suspicious applications immediately.
Look at Screen Time data to identify unusual phone activity. High usage during hours when the phone wasn’t actively used suggests background processes running without permission.
How can I check an Android phone for suspicious apps, permissions, or hidden admin access?
Android users should open Settings and navigate to Apps to view all installed applications. Uninstall anything that looks unfamiliar or wasn’t intentionally downloaded.
Check app permissions by going to Settings, then Privacy or Permissions. Look for apps with access to sensitive features like the microphone, camera, or location that don’t need those permissions.
Review Device Admin apps in Settings under Security. Malware often tries to gain administrator access to prevent removal.
Look at battery usage statistics to identify apps consuming excessive power in the background. Data usage statistics also reveal which apps send large amounts of information.
Which settings should I review to detect unusual activity on my phone without using paid tools?
Battery settings show which apps drain power the most. Unexpected apps at the top of this list indicate potential problems.
Data usage settings reveal how much bandwidth each app consumes. A sudden increase in mobile data usage suggests unauthorized activity.
Check location services to see which apps track location and when. Turn off location access for apps that don’t require it.
Review notification settings for any unexpected two-factor authentication codes. These codes arriving without request often mean someone is trying to access accounts.
Login activity for email and social media accounts shows recent access locations and devices. Any unfamiliar locations or devices require immediate password changes.
What USSD or dial codes can help reveal call forwarding or routing changes on a Samsung phone?
Dialing *#21# shows the current call forwarding status for voice calls, data, and messages. This code works on most Samsung and Android devices.
The code *#62# reveals where calls forward when the phone is unreachable or turned off. Hackers sometimes redirect calls to intercept communications.
Enter ##002# to disable all call forwarding at once. This code stops any active redirects that may have been set up without permission.
Dial *#06# to display the phone’s IMEI number. Write this number down to verify the phone’s identity and report it if the device gets stolen.
What steps should I take immediately if I suspect my phone has been hacked or cloned?
Contact financial institutions first to secure bank accounts and credit cards. Monitoring for unauthorized transactions prevents further financial damage.
Change all passwords immediately using a different device. Create strong, unique passwords for each account rather than reusing the same one.
Remove any suspicious apps from the phone right away. Restart the device after deletion to ensure complete removal.
Install reputable antivirus software from trusted companies like Bitdefender, Norton, or Kaspersky. Run a full scan to detect and remove malware.
Alert contacts that the phone was compromised. Tell them to ignore and delete any suspicious messages that appear to come from the hacked device.
Consider a factory reset if malicious apps keep reappearing. Back up important data to a secure location before resetting the phone to its original settings.