How Can I Tell If My Laptop Was Hacked?

The free Microsoft Defender Antivirus software is built into Windows 11, one good reason to upgrade if you’re one of about two-thirds of PC users in the U.S. who are still using Windows 10. Defender is a part of Windows 10, too, but Microsoft will stop updating software and security for that operating system on Oct. 14 this year.

Numerous antivirus programs from other companies are out there too, some free, others not. Keep in mind that whether you’ve paid for antivirus software or not, the scans won’t catch or eradicate all the malignant software, often called malware, that may be hiding on your laptop.

Hiding is often the right way to put it. Your computer may have been infected with spyware or other concealed programs that steal your keystrokes, passwords or financial data.

Of course, some hacker attacks are painfully obvious, such as when ransomware takes over your laptop. You suddenly cannot open the files on your computer. Then you receive an ominous message from a cybercriminal: The only way to unlock the machine is to pay, sometimes in cryptocurrency.

The good news for you is that businesses or governments are the targets of most ransomware attacks. But that doesn’t rule you out for this type of extortion.

Related: Another darn breach? How to protect your personal data

How your laptop may have been compromised

Before figuring out how to proceed, consider how your laptop could have contracted a virus. Even if you dodged a bullet this time, keep the following in mind to lessen your risk in the future.

1. Toxic links. Were you tricked into clicking on what you believed was a harmless link on a website or in email? Always be careful before clicking any link, even if you think it’s from someone you know.

2. Poisonous attachments. Did you open an email attachment that was not squeaky clean? Unless you’re expecting the attachment, exercise extreme caution before opening it. If possible, reach out to the sender independently to make sure what you received was intended.

3. Website impersonations. Did you stumble onto a sketchy website that may closely resemble a site you thought you were visiting? This could have occurred because you typed a web address incorrectly.

Crooks can trick you by changing a few characters in a domain name, so always check for typos. Enter the proper suffix too, “.gov,” say, instead of “.com.”

You’re probably safe, though nothing’s a sure thing, if you see a 🔒 padlock symbol to the immediate left of the URL, which Apple Safari and Microsoft Edge use to indicate a site adheres to certain security protocols and the data between your computer and a web server is encrypted. In Firefox, you’ll typically see the padlock at a bank, other financial institution or e-commerce site where you’re asked to type in information.

4. Dicey downloads. Did you insert a USB thumb drive or download an application that infected your machine? Again, plug in drives or boot up software only when you’re absolutely confident that the program is what it says it is and came from a trusted person.

Related: What I learned after hackers attacked me and stole $4,000

What you should do next

1. For starters, disconnect the computer from the internet, which may stem any potential loss of data, i.e. keep any busybodies from rooting around inside your machine and grabbing any information that looks good.

2. Run your antivirus software if you haven’t done so already. It won’t catch everything but could be the remedy for your situation.

3. Change your passwords immediately, and avoid using passwords that are the same or similar to ones you’ve employed elsewhere. And make sure your operating system and software are kept up to date.

4. If you are the victim of a ransomware attack, contact law enforcement. The FBI urges people not to pay the ransom, which only encourages similar attacks. The FBI also recommends filing a detailed complaint at its Internet Crime Complaint Center.

If you’re lucky, you have secure backups of the files you cannot access now, meaning those files were not connected to the computer or network that may have gotten compromised. Try opening the backup on another computer. If successful, and you do need to replace your hardware, at least you know not all is lost.

Related: Why experts say everyone should be using a password manager

Bonus tip: Steer clear of fake antivirus software

Sometimes crooks attempt to exploit your insecurities posing behind fake antivirus software. The nerve, right?

Use what your updated computer already has on it; get recommendations from respected technology news websites such as CNET, Laptop Mag, PCMag, TechCrunch or Wired; or go with established brands such as Bitdefender, Malwarebytes, McAfee, Norton or Trend Micro.

And always:

• Keep your guard up.
• Avoid pop-ups that purport to remove a virus or help you with tech support.
• Never pay money or enter credit card credentials on the spot.
• And under no circumstances grant a stranger remote access to your machine.