A pop-up you’ve never seen is telling you your computer is infected. It’s 11:32 on a Wednesday, and you have work to finish.
Take a breath. A scary warning on your screen does not prove your computer has a virus. Some are fake alerts designed to make you call a number, click a link, or pay for help you don’t need. And if something really is wrong, a few careful first steps can help you avoid making it worse.
First, don’t follow instructions in the pop-up
If an alert says to call a phone number, click a link, download a tool, or give someone remote access, don’t do it. Don’t enter a password or payment details, either.
Fake tech-support warnings often imitate messages from familiar companies. Their goal is to rush you into contacting the scammers behind them. The Federal Trade Commission explains how to recognize and avoid tech-support scams.
If the message appeared inside your web browser and you haven’t clicked anything, try closing the tab or browser window. If it won’t close, use your computer’s normal controls to quit the browser. Reopen it without restoring the previous tabs. Don’t use a phone number or link shown in the warning.
What signs should you look for?
One odd moment doesn’t automatically mean malware. A slow computer can have many causes, and a browser pop-up may simply be a bad webpage. Still, pay attention if you notice several unusual changes, such as:
- Getting unwanted pop-ups, especially when you aren’t browsing or when they keep returning.
- Programs you don’t recognize appearing on your computer.
- Your computer suddenly running much slower than usual.
- Files that have unfamiliar names, won’t open, or seem to have changed.
- Security settings or software turning off unexpectedly.
If you’re unsure what you’re seeing, avoid guessing or installing a random “cleaner” tool. Use trusted security software or ask a reliable support person to check.
If files are acting strangely, disconnect first
If files have suddenly become inaccessible, changed names, or a ransom message has appeared, treat it as a possible ransomware incident. Ransomware is malicious software that can lock or encrypt files and demand money to restore access.
Disconnect the affected computer from the internet and other networks. Turn off Wi-Fi and Bluetooth, or unplug the network cable. If it’s connected to shared drives or other computers, avoid using those connections until you’ve received guidance. This can help limit the spread while you work out what happened.
Don’t pay a ransom demand. Paying doesn’t guarantee that your files will be restored, and it can’t assure you that the attacker won’t demand more. The Cybersecurity and Infrastructure Security Agency’s ransomware guide offers practical response and recovery guidance.
If this is your work computer, contact your IT provider or the person responsible for your business technology. Tell them what you saw and what you did next. Don’t reconnect backup drives or shared storage until they’ve been assessed.
If you clicked, downloaded, or shared information
Did you click a link, download a program, or let someone access your computer? Don’t blame yourself. These messages are made to look convincing, and the next steps are manageable.
- Stop using that computer to sign in to email, banking, shopping, or other important accounts.
- From a different device you trust, change passwords for accounts you may have exposed. Turn on two-step verification where it’s available.
- If you shared card or bank details, contact your financial institution promptly.
- If you gave someone remote access, disconnect the computer from the internet and get help from a trusted technician.
- Use trusted security software to scan the computer, or ask a professional to help check and clean it.
The FTC’s malware guidance explains ways to protect your devices and respond to suspected malware. If you lost money or shared personal information, you can also report a tech-support scam at ReportFraud.ftc.gov.
Backups matter before anything goes wrong
It’s easy to put off checking your backups when everything seems fine. But if your computer isn’t backing up, a lost, damaged, or locked device can turn a computer problem into a problem with your business files.
A backup gives you another copy of important information to recover from. It’s not the same as simply seeing your files in a folder that syncs across devices. If a file is damaged or encrypted, changes may sync too. Ask how your backup works, what it covers, and how you would restore a file.
It’s also worth checking that backups are actually completing and that you can restore what you need. A backup you can’t access when you need it isn’t much help.
Do you need antivirus protection?
Antivirus and malware protection can help detect and block malicious software, but it isn’t a reason to ignore suspicious messages or skip backups. Updates, careful sign-in habits, and a recovery plan all matter, too.
If you need antivirus protection for your business computers, consider who will manage it and what happens if a warning appears. Business-class protection can help monitor devices and respond to threats, while managed backup adds another way to recover important files.
For a busy solo business owner, the useful question is not just “Do I have antivirus?” It’s “Do I know what to do if something looks wrong?”
Get help without turning it into a big project
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A few quick questions
Does a pop-up warning mean my computer has a virus?
No. A warning in a browser can be a fake tech-support message. Don’t call the number or click links in it. Close the browser and use trusted security software or support to check if you’re still concerned.
Should I disconnect from the internet?
Disconnect if files are suddenly changing, won’t open, or a ransom demand appears. For a pop-up you haven’t interacted with, close the browser safely and don’t follow the alert’s instructions.
Can a backup protect my business files from ransomware?
A backup can give you a way to recover files, but it’s important to know what it covers and whether it can be restored. Ask how backups are protected and what to do before reconnecting them after a suspected infection.
What if I’m not sure what happened?
Stop interacting with suspicious messages, note what you saw, and contact someone you trust for help. A calm check is better than rushing to call a number on your screen.