Signs that suggest your device has been compromised
A hacked device usually shows one or more obvious changes in how it behaves. Your computer or phone may run slower than normal, even when you are not using demanding programs. You might see pop-up windows that appear without you clicking anything, or your browser might redirect you to websites you did not intend to visit. Some devices display unfamiliar toolbars, change your homepage without your permission, or show ads in places ads should not appear.
Other warning signs include programs launching on their own, your device restarting without you asking it to, or your keyboard and mouse responding with a delay. You might notice your battery drains much faster than it used to, or your device gets hot even when you are not using it heavily. These are all signals that something is running in the background without your knowledge.
Pay attention to your accounts too. If you notice login attempts from places you have never been, or if you receive password reset emails you did not request, someone may have access to your accounts. Friends might tell you they received strange messages from you that you never sent. These are strong indicators that your device or your online accounts have been compromised.
Key Takeaways
- Slow performance, unexpected pop-ups, and unwanted browser redirects are common signs of a hacked device.
- Check your account activity and login history in your email and social media settings to spot unauthorized access.
- Run a full antivirus scan using established security software like Windows Defender, Malwarebytes, or Bitdefender to detect malware.
- Change all your passwords from a different device once you suspect a compromise, starting with your email account.
- If you find evidence of a hack, disconnect from the internet, contact your bank if financial accounts are involved, and consider professional help for serious infections.
How to check your email and account activity
Your email account is the master key to all your other accounts, so start there. Open your email on a computer or phone and look for the account activity section. In Gmail, click your profile picture in the top right, select "Manage your Google Account," then go to the "Security" tab. Scroll down to "Your devices" and look for "Manage all devices." This shows every device that has logged into your email recently, including the location and device type.
Look for logins from places you have never been or devices you do not recognize. If you see suspicious activity, click on that device and select "Sign out" to end that session. While you are in the Security tab, check "Recent security events" to see if anyone tried to change your password or recovery information.
Do the same check on your other important accounts: social media, banking, shopping sites, and cloud storage. Most services have a "Login history," "Active sessions," or "Connected devices" option buried in settings. On Facebook, go to Settings, then "Security and login," and you will see "Where you are logged in." On Microsoft accounts, visit account.microsoft.com, select "Security," then "Recent activity." Remove any sessions you do not recognize.
Running a malware scan on your computer
If your device is running Windows, you already have built-in antivirus protection called Windows Defender. Open it by typing "Windows Defender" into your search bar and clicking "Windows Security." Select "Virus and threat protection," then click "Scan options." Choose "Full scan" — this takes longer than a quick scan but checks every file on your device. Click "Scan now" and let it run to completion, which may take an hour or more depending on how much data you have.
If Windows Defender finds threats, it will quarantine them automatically. You will see a report when the scan finishes. If you want a second opinion, download Malwarebytes from malwarebytes.com. The free version scans for malware; install it, run a full scan, and let it remove anything it finds. Do not run multiple antivirus programs at the same time — they interfere with each other — but running one scan with Windows Defender and then one with Malwarebytes is safe and effective.
For Mac devices, open System Preferences, go to "Security and Privacy," and check the "General" tab to see if your Mac is set to allow only apps from the App Store. You can also download Malwarebytes for Mac from the same website. Run a full scan the same way you would on Windows.
Checking your browser for unwanted changes
Hackers often install browser extensions or change your settings without permission. Open your web browser and look at the toolbar area. Do you see any extensions or add-ons you do not remember installing? In Chrome, click the three-line menu in the top right, go to "Extensions," and review the list. Disable or remove anything unfamiliar by clicking the trash icon next to it.
Check your homepage and search engine settings too. In Chrome, click the three-line menu, select "Settings," then "On startup." Make sure it is set to open pages you actually want. Go to "Search engine" and confirm it is set to Google, Bing, or whatever you use — not something called "Search" or a random name. If your browser has been redirecting you to unwanted sites, these settings are often the culprit.
In Firefox, click the menu button (three horizontal lines) in the top right, select "Add-ons," and review your extensions. Check your homepage the same way: click the menu, go to "Settings," then "Home," and make sure your homepage is what you set it to be. In Safari on Mac, click "Safari" in the menu bar, select "Preferences," go to the "General" tab, and check your homepage setting.
Changing your passwords after a suspected hack
If you found signs of a hack, change your passwords — but do it carefully. Never change passwords on the device you suspect is compromised, because malware on that device can intercept the new password. Instead, use a different device: a phone, tablet, or another computer. If you only have one device, restart it in Safe Mode first, which loads only essential programs and makes it harder for malware to run.
Start with your email password, because your email is the key to resetting all your other accounts. Go to your email provider's website directly by typing the address into your browser — do not click a link in an email. Log in and find the password change option, usually in Settings or Security. Create a new password that is at least 12 characters long and includes uppercase letters, lowercase letters, numbers, and symbols. Write it down in a safe place or use a password manager like Bitwarden or 1Password.
After your email is secure, change passwords on your most important accounts: banking, shopping, social media, and any site that stores payment information. You do not need to change every password immediately, but prioritize accounts with sensitive information. Change the rest over the next week or two.
What to do if you find serious malware
If your antivirus scan found multiple threats, or if your device is still behaving strangely after you have run scans and removed extensions, the infection may be serious. Disconnect your device from the internet immediately — unplug the ethernet cable or turn off Wi-Fi. This stops malware from sending your data anywhere or downloading more threats.
If you have a bank account or credit cards linked to this device, contact your bank by phone using a number from your bank statement or their official website, not from a search result. Tell them you suspect your device has been compromised and ask them to watch your account for unauthorized charges. They may freeze your accounts temporarily or issue new cards as a precaution.
For serious infections, consider taking your device to a local computer repair shop. They have tools and experience to remove stubborn malware that consumer antivirus software sometimes misses. This costs money — usually between 50 and 150 dollars depending on the shop and the severity — but it is worth it if your device is still compromised after your own attempts. If you are not comfortable doing this yourself, professional help is the safest option.
Preventing future hacks
Once you have cleaned your device, take steps to prevent the next infection. Keep your operating system updated by turning on automatic updates in your settings. Updates patch security holes that hackers exploit. Enable two-factor authentication on all your important accounts — email, banking, social media — so that even if someone steals your password, they cannot log in without a code from your phone.
Be cautious about what you download and where you download it from. Stick to official app stores and official websites. Do not open email attachments from people you do not know, and do not click links in unsolicited emails or text messages. If an email claims to be from your bank or a service you use, go to that service's website directly instead of clicking the link in the email.
Use a password manager to create and store strong, unique passwords for every site. This way, if one site is breached, hackers cannot use that password to access your other accounts. Consider using a reputable antivirus program like Bitdefender or Norton if you want extra protection beyond Windows Defender, though Windows Defender is sufficient for most users.
Frequently Asked Questions
Can I tell if I am hacked just by looking at my device?
You can spot some signs — slow performance, unexpected pop-ups, unfamiliar programs, or strange browser behavior — but not all hacks show obvious symptoms. The only way to be sure is to check your account activity and run an antivirus scan. Some malware runs silently in the background without changing anything you would notice.
What if my antivirus scan finds nothing but my device still seems compromised?
Run a scan with a different antivirus program, like Malwarebytes if you used Windows Defender first. Restart your device in Safe Mode and scan again — malware sometimes hides from scans when your device is running normally. If scans still find nothing but problems persist, the issue might be hardware failure rather than a hack, or the malware might be too advanced for consumer tools to detect. A professional repair shop can help diagnose the real problem.
Do I need to replace my device if it has been hacked?
Not usually. Most hacks can be removed with antivirus software and password changes. You only need to replace your device if the infection is so severe that antivirus software cannot remove it, or if the device is so old that it no longer receives security updates. A professional can tell you whether your device is worth saving.
If I change my password, will that remove malware from my device?
No. Changing your password protects your accounts from unauthorized access, but it does not remove malware from your device. You need to run an antivirus scan to remove the malware itself. Do both: scan your device to remove the infection, and change your passwords to prevent hackers from using stolen credentials.
Should I be worried if I see my device in the login history from a location I do not recognize?
Not necessarily. Your location can appear different if you are using a VPN, if your internet provider routes traffic through a different city, or if the location database is simply inaccurate. However, if you see a device you do not own, or a location you have never been to, sign that session out immediately and change your password. It is better to be cautious.