Check for spyware — 5 signs your phone may be compromised

Smartphones have long turned into personal safes containing messages, photos, passwords, and banking apps, making them a more valuable target for criminals than laptops. A single careless action, a suspicious app, or a click on a phishing link can open the door to your data.

SlashGear writes about the signs that may reveal hackers’ activity on your smartphone.

Suspicious apps and intrusive ads

If you notice an app on your phone that you definitely didn’t install, that’s a serious reason to be cautious — especially if it appeared after downloading something outside the official app store.

The two most common types of smartphone malware are adware and Trojans. Adware floods users with pop-up ads, generating illegal profits for its distributors. Trojans are more dangerous; they can intercept passwords, read messages, and provide attackers with remote access to your data.

If you suddenly start seeing strange banners, ad windows, or unfamiliar apps, it’s best to immediately check what's installed on your device.

Phone suddenly slows down

Another alarming sign is a sharp drop in performance. The smartphone begins to take longer to open apps and freezes, even though all programs are closed and background activity is limited.

This may indicate that hidden malware is running in the background: it loads the processor, consumes RAM, and uses system resources, but remains invisible on the screen. If such behavior appears suddenly, without updates or the installation of "heavy" apps, it’s worth taking a closer look.

Battery drains faster and smartphone heats up without reason

Cryptominers, spyware, and other types of malware often run in the background constantly. As a result, your phone's battery drains noticeably faster, even when you use it as usual or when it's idle.

Another warning sign is overheating for no apparent reason. If your device heats up when you aren't using games, the camera, or navigation, a hidden program may be loading the processor.

You can check this in the Settings → Battery menu, where you can see that apps consume the most energy. If you see an unfamiliar app draining an unusually large amount of power, investigate it immediately.

Unusually high mobile data usage

Another indirect sign of outside interference is a sudden increase in mobile traffic consumption. If you haven’t changed your habits, but your carrier bill or the statistics in settings show a significant rise in data usage, it may mean that information from your smartphone is being sent to external servers.

Spyware apps often transmit logs, call history, SMS, location, or other data in the background — and all of this requires traffic.

Verification codes you didn't request and phishing messages

Phishing remains one of the most effective tools for fraudsters. Messages can arrive via SMS, email, or messengers and may look like official notifications from a bank, service, or social network.

It is especially dangerous when your phone starts receiving login confirmation codes that you did not request. This may indicate that someone is trying to log into your account using already stolen data, and now they only need the one-time code.

If such messages become regular, it is a serious signal that your accounts or phone number are already in the sights of attackers.

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