How to Know If Your Phone Is Hacked | 10 Warning Signs in 2025

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Introduction: That Nagging Feeling Something Is Wrong

You pick up your phone and something just feels off. The battery is draining faster than usual. Apps are crashing for no reason. Your mobile data disappears overnight. You tell yourself it’s just a software glitch — but deep down, a small voice whispers: has my phone been hacked?

You’re not being paranoid. In 2025, knowing how to know if your phone is hacked is as essential as locking your front door. According to a 2025 mobile threat report by Zimperium, 18.1% of all mobile devices globally had malware installed — that’s nearly 1 in 5 phones. Your smartphone stores your banking apps, private messages, two-factor authentication codes, and years of personal memories. For a hacker, it’s a jackpot.

This guide walks you through the clearest warning signs, the sneaky methods hackers use to get in, and exactly what to do if your phone has been compromised.

How Do Phones Get Hacked?

Before you can spot the signs, it helps to understand how hackers get in. Most phone hacks don’t involve a genius sitting in a dark room writing code. They’re far more opportunistic — and far more common — than most people realize.

Malicious apps are one of the biggest culprits. Disguised as games, flashlight tools, or productivity apps, they quietly install spyware once downloaded — often from unofficial app stores outside Google Play or the Apple App Store. Phishing links are equally dangerous; a single tap on a sketchy SMS or email can silently install tracking software on your device. Public Wi-Fi networks are another weak spot, where attackers can intercept your data through what security researchers call a man-in-the-middle attack.

More targeted attacks include SIM swap fraud, where a criminal convinces your mobile carrier to transfer your phone number to a new SIM they control, giving them access to your calls, texts, and two-factor authentication codes. Stalkerware — software designed to hide in plain sight — is often installed by someone who had brief physical access to your phone. Even your cloud backup can be a vulnerability; a compromised Google or Apple account gives hackers access to everything you’ve ever synced.

10 Warning Signs Your Phone Has Been Hacked

1. Your Battery Is Draining Much Faster Than Usual

This is one of the most overlooked — and most revealing — signs. Cybersecurity expert Akash Mahajan warns that sudden, unexplained battery drain is often caused by malicious software running silently in the background, continuously collecting and transmitting your data to a remote server.

Most people blame an aging battery or heavy screen time. But if your battery life has dropped dramatically with no real change in your habits, it’s worth investigating. Go to Settings → Battery → Battery Usage and look for apps consuming power that you don’t recognize or rarely use.

2. Your Phone Feels Hot Even When You’re Not Using It

Malware doesn’t take breaks. When malicious software runs constantly in the background, it burns through your phone’s processing power — which generates heat. If your phone feels warm or hot while it’s just sitting on a table doing nothing, that’s a red flag.

According to McAfee’s mobile security researchers, overheating while idle is a consistent sign that something is overworking your phone’s processor without your knowledge.

3. Unfamiliar Apps Have Appeared on Your Device

Hackers sometimes disguise malicious software as normal-looking apps, or silently install additional apps as part of a larger payload. If you notice apps on your phone that you don’t remember downloading — especially apps that look like system tools or generic utilities — treat them with suspicion.

Go through your full app list carefully. If something looks unfamiliar, search for it online before deleting it to confirm it’s not a legitimate system app you simply overlooked. You can also use Google’s Play Protect to scan installed apps on Android.

4. Your Data Usage Has Spiked Unexpectedly

Spyware needs to send your stolen information somewhere — and it uses your mobile data to do it. A sudden and unexplained spike in data consumption is one of the more measurable signs that something is communicating in the background without your permission.

Check your data usage in Settings and look for apps using data in ways that don’t make sense. A calculator app consuming gigabytes of data is not a glitch — it’s a warning sign. The FTC recommends monitoring your data usage regularly as part of basic mobile security hygiene.

5. You’re Locked Out of Your Accounts

If you suddenly can’t log in to your email, social media, or banking accounts, a hacker may have already stolen your credentials and changed the passwords to lock you out. This is known as Account Takeover Fraud, and it often starts with spyware capturing your keystrokes or login sessions.

Receiving unexpected two-factor authentication codes you didn’t request is another strong signal. It means someone has your password and is actively trying to get past your second layer of security. You can check if your credentials have been exposed in a known breach using Have I Been Pwned, a free and trusted tool used by millions.

6. Strange Calls, Texts, or Purchases Are Appearing

If people in your contacts are telling you they received strange messages from you — or if your phone bill shows calls and texts you never made — your phone is almost certainly compromised. Hackers can use your device to send phishing messages to your contacts, make premium-rate calls, or conduct SMS-based scams, all at your expense.

Check your outgoing call log and sent messages regularly. Anything you don’t recognize should be investigated immediately. If fraudulent charges appear on your account, report them to your carrier and follow the FTC’s identity theft recovery steps.

7. Your Camera or Microphone Is Activating on Its Own

This one is unsettling, but it happens. Malicious apps can secretly access your camera and microphone, potentially recording audio or video and streaming it to an attacker without your knowledge. Key warning signs include the camera indicator light turning on unexpectedly, or finding photos and videos in your gallery that you never took.

On both iPhone and Android, you can review which apps have permission to access your camera and microphone in your device settings. Apple’s support guide walks iPhone users through revoking app permissions step by step.

8. You’re Seeing More Pop-Ups and Ads Than Normal

An influx of aggressive pop-up ads — especially ones that appear outside of browsers, redirect you to strange websites, or launch apps on their own — is a hallmark of adware, a type of malware designed to generate ad revenue for the attacker at your expense.

If this is happening on your phone, check your mobile browser’s extensions first. On iPhone, go to Settings → Safari → Extensions and remove anything unfamiliar. On Android, check your installed apps and browser settings. Malwarebytes has a free Android scanner that’s particularly effective at detecting adware.

9. Websites Look Strange or Redirect You Unexpectedly

Some forms of spyware can modify how websites appear on your device, particularly login pages, where the goal is to steal your credentials as you type them. If websites you visit regularly look visually different, redirect you to unexpected pages, or prompt you to re-enter your password for no clear reason, your web traffic may be getting hijacked.

This is especially common after connecting to unsecured public Wi-Fi networks. Using a trusted VPN like ProtonVPN or Mullvad on public networks adds a layer of encryption that makes this type of attack significantly harder to execute.

10. Your Phone Takes Unusually Long to Shut Down

When shutting down takes longer than usual, or your device freezes before turning off, it could be a sign that your phone is transmitting data or completing background tasks before it fully powers down. Surveillance apps are sometimes designed to maintain access and finish operations before the device shuts off.

According to Malwarebytes’ cybersecurity researchers, this delayed shutdown behavior is one of the more specific indicators of active surveillance software on a device.

Quick Reference: Signs vs. Likely Causes

Warning Sign	Possible Innocent Cause	More Likely a Hack When…
Battery draining fast	Old battery, high screen time	Drain is sudden with no habit changes
Phone overheating	Heavy gaming or charging	Happens while idle and unused
Unknown apps	Pre-installed bloatware	App appeared recently without you installing it
Data spike	New streaming habits	Spike is overnight or tied to unknown apps
Account lockout	Forgot password	Combined with unauthorized 2FA requests
Strange texts sent	Messaging bug	Recipients confirm receiving unusual messages
Pop-up ads	Normal web browsing	Ads appear outside browsers or in system UI

What to Do If You Think Your Phone Is Hacked

Acting fast limits the damage. Here’s a clear, step-by-step response plan recommended by security experts at Malwarebytes and Norton LifeLock:

Step 1 — Disconnect immediately. Turn on airplane mode and disable Wi-Fi and Bluetooth. This cuts the hacker’s connection to your device and stops active data transmission.

Step 2 — Run a security scan. Download a reputable mobile security app from the official App Store or Google Play — such as Malwarebytes, Norton, or McAfee — and run a full scan to detect and remove threats.

Step 3 — Change your passwords from a different device. Use a laptop or a trusted friend’s phone to change your email, banking, and social media passwords. Never change passwords from the compromised device until it’s been cleaned.

Step 4 — Enable multi-factor authentication. Add an extra layer of security to all critical accounts, ideally using an authenticator app like Google Authenticator or Authy rather than SMS codes, which can be intercepted via SIM swap attacks.

Step 5 — Audit your app permissions. Go through every app on your phone and disable camera, microphone, location, and contacts access for anything that doesn’t genuinely need it.

Step 6 — Update your operating system. Software updates patch known security vulnerabilities that hackers exploit. Never ignore them. On both Android and iPhone, keeping your OS up to date is one of the most effective defenses you have.

Step 7 — Factory reset as a last resort. If threats persist after all of the above, back up your essential data to a secure cloud account, then perform a full factory reset. This eliminates most forms of malware. After resetting, change all your passwords again before restoring data.

If you’ve suffered financial fraud or identity theft, report it to the Cybersecurity and Infrastructure Security Agency (CISA) or file a complaint with the FBI’s Internet Crime Complaint Center (IC3).

How to Protect Your Phone Going Forward

Prevention is always easier than recovery. Here are the habits that security professionals consistently recommend:

Keep your OS and all apps updated at all times
Only download apps from Google Play or the Apple App Store
Never tap links in unsolicited SMS messages or emails
Use a trusted VPN on public Wi-Fi networks
Disable Bluetooth when you’re not actively using it
Use strong, unique passwords stored in a password manager like Bitwarden or 1Password
Enable biometric authentication — Face ID or fingerprint — wherever possible
Regularly review and revoke unnecessary app permissions

Frequently Asked Questions

Can my phone be hacked without me clicking anything? Yes. Zero-click attacks exist and have been used in targeted surveillance campaigns, most notably with Pegasus spyware. However, for the average user, most hacks still require some form of interaction — clicking a link, downloading an app, or connecting to a malicious network.

Can iPhones be hacked? Absolutely. While Android devices receive significantly more malware threats due to the open app ecosystem, iPhones are not immune. Phishing attacks, compromised Apple ID accounts, and malicious Wi-Fi networks can all affect iOS devices.

Will a factory reset remove all hacking software? In most cases, yes. A factory reset erases all installed apps and data, including spyware. However, if your device has been jailbroken or rooted, some advanced malware can embed itself in the firmware and survive a reset. In those cases, professional help may be needed.

Can someone hack my phone just by calling me? A standard phone call cannot hack your device. However, sophisticated attacks like the Pegasus spyware have exploited missed call vulnerabilities in apps like WhatsApp. These are rare, highly targeted attacks — not the typical threat most people face.

How do I know if I have stalkerware on my phone? Stalkerware is designed to be invisible, but signs include unexpected battery drain, a phone that’s always warm, and a contact who seems to know your whereabouts without being told. The Coalition Against Stalkerware offers resources and guidance if you suspect you’re being monitored.

Is there a code I can dial to check if my phone is hacked? Yes. Dialing *#21# on most phones shows if your calls or messages are being forwarded to another number. Dialing ##002# cancels all call forwarding. These won’t detect all forms of hacking, but they’re a quick check for call-diversion attacks.

Should I be worried if my phone gets hot while charging? Mild warmth while charging is completely normal. What’s abnormal is significant heat while the phone is idle, not plugged in, and not running any visible apps. That’s the scenario that warrants concern.

Final Thoughts

Your smartphone is arguably the most personal device you own — and that makes it the most valuable target for cybercriminals. Knowing how to know if your phone is hacked isn’t about living in fear; it’s about staying one step ahead. The warning signs are often subtle at first: a battery that drains a little faster, an app you don’t remember installing, a login that suddenly stops working.

Trust your instincts, act quickly when something feels wrong, and build habits that make your phone a harder target. Cybersecurity doesn’t have to be complicated — it just has to be consistent.

If this guide helped you, share it with someone who could use it. And if you spotted something suspicious on your device, drop a comment below — we’d love to help you figure it out.