How to Tell if Your Phone Has Been Hacked
June 17, 2025 • César Daniel Barreto

People now store more sensitive information on their phones than ever before. From work login credentials to credit card details, pretty much everything that’s important is just a tap away at all times. Unfortunately, this convenience comes with a cost. If a hacker breaks into your phone, they gain access to all your data. The worst part? You may not even realize it’s happening.
That’s why in this article, we look at five warning signs that your phone may have been hacked and what you can do about it.
Unrecognized Logins
One of the surefire signs of a hacker attack is noticing logins into your accounts from devices or locations you don’t recognize. Most social media platforms and other services like Gmail send notifications when they detect a new login from an unfamiliar device or IP location. If you haven’t signed in yourself, it indicates somebody got their hands on your credentials.
From that point, they can access all your chats, photos, and even linked accounts. Moreover, they can pretend to be you and try to scam your friends or family members. In other words, it’s a very serious breach that requires immediate action to prevent further damage.
The first thing to do in this situation is to log out of all devices and change your password to something you haven’t used before. Additionally, you may want to enable two-factor authentication to add an extra layer of security.
To avoid falling victim to this type of attack in the first place, be extra careful where you leave your login data. When signing up for a new website, do some research to ensure it’s safe to use. For example, if you’re trying a new productivity app or cloud storage service, check reviews and user feedback first. Similarly, if you’re playing payline slots, make sure the platform is reputable and uses secure payment methods.
Battery Draining Quickly
If your battery is draining quickly, it could be a sign that it’s time to change it. However, it could also indicate that you have spyware running in the background and constantly using system resources. The tricky part is that apps like this operate silently and it’s not always easy to find them.
Another thing that often happens in this situation is that the phone gets warm even when you’re not using it. The subtle signs are warning signs that something suspicious may be happening in the background.
In case you notice either of these signs, it’s time to act. Start by going through all apps installed on your device and reviewing anything you weren’t aware of having. Keep in mind that not everything you don’t recognize is necessarily malicious. Some system tools or manufacturer apps may install automatically with new updates or OS patches.
To stay safe, always have an antivirus or antimalware app installed on your app. These tools will review anything new that gets downloaded or installed and alert you if something looks wrong.
Phone Running Slower
A similar sign to rapid battery drain is your phone running slower without a real reason. The culprit is often the same — hidden spyware running in the background and taking valuable resources from the apps you’re actually using.
Unlike legitimate apps, this spyware cannot be closed or uninstalled easily. So, if you notice your apps taking forever to load or being less responsive than before, it could be a sign of something else running behind the scenes.
The remedy is the same as with rapid battery drain. Review all your apps and data usage, and install a security app that’ll be able to detect spyware automatically.
Another smart thing to do is to run your device in safe mode. Spyware won’t be able to operate in this mode, and you might notice things running smoother. From there, you can start reviewing and uninstalling newly downloaded and unfamiliar apps.
If you still can’t identify the app that’s slowing your device down, you can always perform a factory reset. This will wipe all data from your phone and give you a clean slate. Just make sure to back up photos, contacts, and other data you don’t want to lose.
Strange Behavior
One of the common hacking techniques involves installing keyloggers that monitor your activity and record everything you write. When one of these finds its way into your phone, the hacker behind it will see not only your messages but also your login credentials and banking information.
Like other spyware, keyloggers operate quietly in the background and are difficult to detect. They may not necessarily slow down your phone, but some signs could give them away.
Keyloggers often cause strange device behavior such as apps crashing, settings changing on their own, or long delays and autocorrect failure when typing.
These apps can be removed from your device in the same way as other spyware apps can. However, it’s also important to change all your login credentials because the hacker may have already saved your passwords and other sensitive information.
The safest way to reset your passwords is from another secure device to avoid giving the attacker another opportunity to steal your data.
Pop-Ups and Redirects
Pop-ups have been one of the biggest indicators of viruses and other forms of malware since the early days of the internet. They still serve as a red flag today, especially on mobile devices.
If you start seeing frequent pop-ups and redirects to suspicious websites, it could mean you’re dealing with adware or malicious software.
You’ve probably seen these pop-ups at some point, but be extra careful with those that look like virus alerts, promotional offers, or prize notifications. They’re designed to make you tap on them and be redirected to phishing pages that may try to steal your personal data.
Your safest bet is to eliminate them entirely. Begin by installing an adblocker on your device and clearing your cache and history.
Conclusion
Even if you believe you’re safe, there’s always a chance of somebody breaking into your phone and trying to steal your data. Make a habit of regularly reviewing your device’s performance, checking for unfamiliar apps, and monitoring account activity. If you notice something suspicious, reacting quickly will minimize the damage and potentially save you from financial loss, identity theft, or further breaches.

César Daniel Barreto
César Daniel Barreto is an esteemed cybersecurity writer and expert, known for his in-depth knowledge and ability to simplify complex cyber security topics. With extensive experience in network security and data protection, he regularly contributes insightful articles and analysis on the latest cybersecurity trends, educating both professionals and the public.