Blog – Infurpose — Phone Privacy & Security Guides

Quick answer: The clearest signs your Android phone has been hacked are fast battery drain and overheating, unexpected data-usage spikes, pop-up ads appearing outside your browser, apps you never installed, sudden slowdowns or crashes, and unexpected charges on your bill. If a few of these sound familiar, this Infurpose guide covers the seven warning signs and exactly what to do about them. The 7 Signs Your Android Phone Has Been Hacked No single symptom proves your phone is hacked, but several of these together are a strong signal that something malicious is running in the background. 1. The battery drains fast and the phone overheats Malware and spyware run constantly, hijacking your processor to track activity or mine data, which drains the battery and heats the phone even when it's idle. Open Settings, then Battery, and look for an unfamiliar app quietly using far more power than it should. 2. Your data usage spikes without explanation A hacked phone often sends your information to someone else in the background, which shows up as a sudden jump in mobile data. Check Settings, then Network & internet, then app data usage to spot an app consuming data that has no reason to. 3. Pop-up ads appear outside your browser If you're seeing intrusive pop-ups on your home screen or inside apps when you're not browsing the web, that's a classic sign of adware or a malicious app. Legitimate ads stay inside the app or browser you're using — pop-ups that follow you everywhere do not. 4. Apps you never installed show up Open your app drawer and Settings, then Apps, then See all apps, and look for anything unfamiliar — especially apps that are hard to remove or have vague, system-sounding names. Malware often installs extra apps, and some disguise themselves to avoid attention. 5. The phone suddenly slows down, freezes, or reboots When malicious software competes for your phone's resources, everything else gets sluggish. Frequent freezing, crashing, or random restarts that started recently — with no new demanding apps of your own — can point to something running that shouldn't be. 6. You see unexpected charges or premium texts Some malware signs you up for premium text services or makes charges without your knowledge. Review your phone bill and app subscriptions for anything you don't recognize; unexplained charges are one of the most concrete signs of a compromise. 7. There's strange account activity or call forwarding Watch for login alerts from unfamiliar locations, password-reset emails you didn't request, or calls and texts that never reach you. You can dial *#21# on your Android to check whether your calls or texts are being forwarded somewhere without your knowledge, then reset it if needed. Hacking or Stalkerware — Which Are You Dealing With? It helps to know whether you're facing a random criminal or someone close to you, because the response differs. A traditional hack usually comes from a stranger through a malicious link, app, or public Wi-Fi, and aims to steal data or money. Stalkerware, by contrast, is installed deliberately by someone who knows you and had physical access to your phone, and it's designed to monitor you specifically. If the "hack" lines up with a controlling partner, ex, or family member knowing things they shouldn't, treat it as a potential stalkerware situation and read the safety note in the next section before you act. The distinction matters for a practical reason: a random malware infection is safe to remove the moment you find it, because the attacker doesn't know you personally and won't retaliate. Stalkerware installed by someone in your life is different — removing it can tip that person off. When you're not sure which one you're dealing with, it's safer to assume the more sensitive case and plan accordingly. Android's openness makes both possible: it's easier to install apps from outside the Play Store than on an iPhone, which is convenient for you but also convenient for anyone who wants to slip something onto your device. From experience: On an Android I suspect is compromised, the very first place I look is Accessibility and Device Administrator settings. An app you don't recognize sitting in either list is the biggest red flag there is — those permissions let it read the screen, capture what you type, and resist being uninstalled. If something unfamiliar is in there, that's where I start. What to Do If Your Android Has Been Hacked Work through these steps in order rather than panicking and wiping the phone right away. If there's any chance the person responsible is someone close who could react badly, plan with a domestic violence advocate first — the National Domestic Violence Hotline (thehotline.org or 1-800-799-7233) can help. Turn on airplane mode to cut the phone off from the internet and stop data leaving the device. Delete unfamiliar apps you identified above through Settings, then Apps. Run a scan with Google Play Protect (open the Play Store, tap your profile, then Play Protect) or a reputable security app to catch what you can't see. Change your passwords from a safe device — starting with your Google account — and turn on two-factor authentication. Revoke risky permissions under Settings, then Security & privacy, and remove Accessibility or Device Admin access from anything suspicious. Factory reset as a last resort, and set the phone up fresh instead of restoring an old backup that could reinstall the problem. How to Keep Your Android From Being Hacked Prevention comes down to closing the doors attackers use. Keep your Android and its apps updated, since updates patch the security holes malware exploits. Install apps only from the Google Play Store, review the permissions each app requests, turn on two-factor authentication for your important accounts, and lock your phone with a strong PIN or biometric only you know. A few extra habits go a long way. Be wary of links in texts and emails from people you don't know, since a single tap can install malware. Avoid entering passwords or banking details on public Wi-Fi without a VPN, and turn off Bluetooth when you're not using it. Finally, glance through your installed apps every month or so — catching an unfamiliar app early is far easier than untangling a full compromise later. Infurpose's Android privacy settings guide walks through exactly which switches to flip. Frequently Asked Questions How do I know if my Android is hacked or just old?An aging phone slows down gradually and evenly. A hacked phone tends to show sudden changes — new apps you didn't install, pop-ups outside the browser, data spikes, or unexpected charges. Several of those together point to a hack rather than age. Does a factory reset remove hackers from my phone?Yes, a full factory reset removes almost all malware and spyware — but only if you set the phone up fresh afterward and avoid restoring an old backup that could reinstall it. Change your account passwords from a safe device once you're done. What does dialing *#21# do?It shows whether your calls, texts, or data are being forwarded to another number without your knowledge. If forwarding is active and you didn't set it up, you can disable it and contact your carrier. Can Google Play Protect detect everything?Play Protect catches many threats, but some well-hidden spyware slips past it. Use it as a first check, then combine it with reviewing your installed apps, permissions, and account logins. Could someone I know have done this?Yes. If the signs match someone close knowing private details about you, it may be stalkerware rather than a random hack. In that case, make a safety plan before removing anything, since cutting off access can alert them. The Bottom Line Fast battery drain and heat, data spikes, pop-ups outside your browser, unknown apps, sudden slowdowns, surprise charges, and strange account activity are the seven signs your Android may be hacked. Start by disconnecting, scanning with Play Protect, and changing your passwords from a safe device — and if the culprit might be someone close to you, plan with trained help before you act. If reading this confirmed a nagging worry, taking it seriously is the right call. Explore Infurpose's guides on removing spy apps and securing your accounts to get your Android back under your control. Written by Samuel Smith, Consumer Technology Writer & Digital Privacy Researcher at Infurpose. This article is for general information and is not legal advice.