Has Your Computer Been Hacked Without You Knowing It?

Everybody worries about their computer getting hacked, just as some of us are occasionally concerned that our phones have been tapped. It’s natural to worry about your security online, especially as we do more banking, shopping, backing up our files, and socializing over the internet. Has your computer been hacked by a black-gloved attacker with a personal vendetta against you? Probably not. But it’s becoming more and more common to have your systems and accounts compromised by automated software or via online vulnerabilities.

Ahead, read up on how you can figure out whether your computer has been hacked without knowing it. And make sure that you know how to respond if your computer has been hacked, and what you need to do to prevent future hacks.

How to tell if your computer has been hacked

A computer hacker stealing credit card information

You may be a victim of a computer hacking without even realizing it | iStock.com

If your computer has been hacked, it’s easy for some time to elapse before you figure out what’s going on. But there are some obvious signs to look out for. You may receive a call or message from your bank or your credit card company alerting you to suspicious activity. Your friends may send you messages saying that they received unusual messages from your email address. Or, you might find new toolbars in your web browser. You might notice new software installed on your computer. Or, your computer’s behavior may change. It might start acting strangely, or its performance might slow down significantly.

Roger A. Grimes reports for InfoWorld that some “sure signs” that your computer has been hacked include fake antivirus messages, unwanted browser toolbars, and redirected internet searches. Frequent, random popups, fake emails being sent from your personal accounts, and passwords that suddenly change are also red flags. You should also be worried if you notice unexpected software installs, if your mouse moves you between programs, or if your antivirus software, Task Manager, or Registry Editor is disabled and can’t be restarted. Finally, if your bank account is missing money or if stores call about insufficient funds for shipped goods, you should suspect a hack.

Nonetheless, most hacks aren’t as dramatic as movies might indicate. Christian Cawley reports for MakeUseOf that actually recognizing a hack can be tricky. Self-important hackers “might leave you a note — perhaps a bit of desktop graffiti or a malware ‘time bomb’ — but those are rare,” Cawley notes. “Most hacks are courtesy of Trojan software and related automated tools, so uncovering an intrusion — particularly an online one — can prove difficult.”

Other ways to determine whether your computer has been hacked

Businessman looking at his laptop

Most hackers leave very few clues that you’ve been hacked | iStock.com

If you suspect that you’ve been hacked, think about where you might be vulnerable. If you have sensitive, private files stored on your computer, check them in your directory browser. Cawley recommends noting their “Last Modified” times and dates, but not opening them. Opening them could activate malware. Instead, run an antivirus or anti-malware app, and make backups of the files and folders before opening them.

You should also check your firewall software and find the log where its activities are stored. Cawley notes that if there’s been an attempt to hack your computer in the past few days, that will show up in the log. But you shouldn’t take the lack of a successful intrusion record as evidence that there was no hack at all. It could also mean that the hacker is “skilled in keeping their fingerprints off your ports.” But Cawley reports that “in 99.9% of cases a good quality firewall will keep your computer secure.”

If you don’t already have a firewall installed on your computer, there are some other things you can check. You can check the logs on your router to determine whether your computer has been hacked and any of its data copied. But Cawley warns that tracking that kind of information down can be pretty time-consuming, so you’ll need to have an idea of when the hack occurred.

You’ll quickly be able to tell if a Trojan is running on your system and has opened remote access to your computer. Slow performance, plus network activity when you aren’t using your browser, email client, or an IM client point to an intrusion. So will the more obvious, but more rare, loss of control over your computer. If the network activity seems odd, then you can switch off your router or disconnect your Ethernet cable, since the hacker has probably disabled your ability to disconnect within the operating system. After you disconnect, you should restart your computer and then, staying offline, run your antivirus software. Then, use a secondary computer to download an update to your firewall software and install it on your primary computer.

What to do if your computer has been hacked

Portrait of upset young woman in front of her computer

Having your computer hacked can be stressful, but you can take action | iStock.com/JackF

You should always keep an eye out for the signs that your computer has been hacked. To be as safe as possible, you should perform a complete computer restore once you detect a breach. As Grimes reports, “the bad guys can do anything and hide anywhere” once your computer has been compromised. In that case, “it’s best to just start from scratch.” Restoring your system isn’t as scary and time-consuming as it sounds. Depending on your operating system, it may be as simple as hitting a “Restore” button.

You should also reset all of your passwords after a hack. Start with your email account. Then proceed to your financial accounts, and other important accounts. (You should start with your email because that’s where all of the password reset messages for your other accounts will go.) If you get locked out of an account, follow the website’s instructions for regaining access.

If you think that your email or your social media accounts were compromised, let your friends know that you’ve been hacked. Report the issue to any site that was involved. Scan your computer with a trusted (and up-to-date) antivirus program. If your identity has been stolen, get a copy of your credit reports, and file a fraud alert with Equinox, Experian, and TransUnion. You should contact the police to report the identity theft, and request new cards from your bank and your credit card issuers. Going forward, you should monitor your statements for unusual activity.

You can’t completely eliminate the risk of getting hacked, having your identity stolen, or falling victim to other online crimes. But by following basic security protocols and being aware of what to look for, you’re a step closer to minimizing the damage if or when your computer is hacked.

What to do to prevent your computer from getting hacked

Man on his computer outdoors

Keep your antivirus software up-to-date to avoid computer hacks | iStock.com

You should always run up-to-date firewall and antivirus software to protect your computer. You should also consider a registry protection tool, and take advantage of hard disk encryption tools. Keep your operating system updated, and pay attention to the new security features rolled out with updates.

Bonnie Cha reports for Recode that you can take many precautions to protect yourself against hacking online, too. You should create strong, unique passwords for each account you use. It can help to set up a password manager to keep track of those passwords. Additionally, password managers can generate strong passcodes for you. That makes it easier to use strong, random passwords that are difficult to crack. It’s a good idea to enable two-factor authentication where supported. Two-factor authentication protects your accounts by requiring you to provide an extra form of authentication, like a PIN code sent to your phone. It adds an extra layer of protection, and services from Google, Apple, Facebook, Microsoft, and Dropbox support it.

Additionally, you should always exercise common sense when sharing personal information online. Don’t respond to emails, ostensibly from your bank or credit card issuer, demanding immediate action or requiring you to click suspicious links. If you receive such an email, call the institution and verify the email’s authenticity. Similarly, never click suspicious links. Don’t browse unsafe websites. Don’t install apps from untrustworthy sources. Ensure that your OS and apps are all current on updates.

Finally, watch what you do online. Be aware of the things you should never post on Facebook. Make sure your email and social media accounts are keeping your information private. Keep track of which files you have in cloud storage. Be wary of using free Wi-Fi networks when you’re making transactions or sharing personal information. Don’t engage with pop-ups. And make sure that your home Wi-Fi network is using WPA-2 with AES encryption settings.