The signs your account or device has been hacked can be subtle and easy to ignore, but spotting them early can keep them from spiraling into a larger problem. These are the early signs to watch for to help you nip a security breach before it becomes more serious.

An unexpected password reset request - If you get one of these or a two-factor authentication code text or email that you didn’t initiate, it could mean someone is trying to get access to your accounts.
Unrecognized login attempts - It’s a red flag if you’re not trying to access your account and get a notification of a login attempt, so you should change your password right away.
Unusual device behavior - If your computer or phone suddenly starts acting differently, it may have been compromised with malware. Warning signs include rapid battery drain or overheating when you’re not using it, processes like shutting down taking longer than usual, unusual permissions requests and spikes in data usage.
Finding an app you didn’t download - Seeing an app you don’t remember downloading on your device is cause for alarm, as it could be spyware or another type of malware that can be used to track your activity or steal your information.
Increased spam calls or emails - We all get phishing emails and spam calls and texts, but if you start getting a lot more of them suddenly, scammers may be targeting you. It could be a data breach, so watch for notices and use the dark web monitoring tools in your password manager.
Test charges on credit cards - Hackers who get access to your financial accounts may test which ones still work before making larger purchases. Check your statements regularly and if you see charges for as little as a few cents, don’t ignore them.
New messages or emails marked as read - This is a warning sign someone has accessed your account and looked at it on another device.
Being locked out of an account - If you can’t get into your account, it could be because hackers have tried and failed to log in too many times.
Strange content in your streaming history - See things in your Netflix, Spotify or YouTube history that you didn’t stream? It could be a sign someone got access to your account, which may not seem like a big deal, but could lead to bigger issues if your data has been compromised.

Source: Lifehacker