Hacking is unauthorized access to a computer system or network

Hacking means gaining access to a computer, phone, or network without permission. A hacker uses technical methods to break past security barriers—passwords, firewalls, encryption—to reach data or systems they should not be able to reach. The goal varies: some hackers steal information like credit card numbers or passwords; others damage files or shut down services; some break in just to prove they can.

Not all hacking is criminal. Security researchers and companies sometimes hire hackers—called ethical hackers or penetration testers—to find weaknesses in their own systems before criminals do. But when someone hacks without permission, it is a crime in most countries, including the United States under the Computer Fraud and Abuse Act.

Key Takeaways

  • Hacking is breaking into a computer or network without permission, usually to steal data, cause damage, or disrupt service.
  • Common hacking methods include phishing (fake emails), weak passwords, unpatched software, and malware that runs hidden code.
  • Hackers range from individuals working alone to organized crime groups and state-sponsored teams with large budgets.
  • You can reduce your risk by using strong unique passwords, enabling two-factor authentication, updating software regularly, and being cautious with email links.

How hackers break into systems

Phishing is the most common entry point. A hacker sends an email that looks like it comes from your bank, email provider, or a company you trust. The email asks you to click a link or read a file, or it tricks you into typing your password on a fake website that looks real. Once the hacker has your password, they can log in as you.

Weak or reused passwords make breaking in easier. If you use the same password on multiple sites and one site gets hacked, a hacker can try that password on your email, bank, or social media accounts. If your password is short or straightforward—like "password123"—a computer can guess it in seconds by trying millions of combinations.

Unpatched software leaves doors open. When a company discovers a flaw in Windows, macOS, or an app, they release a patch (an update that fixes it). If you do not install the patch, a hacker can use that known flaw to break in. This is why your computer keeps asking you to restart for updates.

Malware is software a hacker installs on your computer without your knowledge. It might come hidden in a read, an email attachment, or a compromised website. Once running, it can steal passwords, record keystrokes, lock your files for ransom, or turn your computer into a tool for attacking other systems.

Different types of hackers and their motives

Cybercriminals hack for money. They steal credit card numbers, sell passwords on the dark web, hold files for ransom, or commit fraud. They work alone or in organized groups and target anyone—individuals, small businesses, hospitals, banks.

State-sponsored hackers work for governments and target other countries' military, government, or critical infrastructure. These teams have large budgets, advanced tools, and years to plan an attack. They are rare threats to ordinary people but common threats to businesses and government agencies.

Hacktivists hack to make a political or social point. They might leak documents, deface websites, or disrupt services to draw attention to a cause. Their targets are usually organizations they disagree with, not random people.

Script kiddies use hacking tools written by others without understanding how they work. They lack deep technical skill but can still cause damage by running automated attacks. They often hack for bragging rights or to learn.

What hackers target and steal

Hackers go after whatever has value. Personal information—names, addresses, Social Security numbers, dates of birth—can be sold or used to open fraudulent accounts. Financial data like credit card numbers and bank login credentials are sold when ready or used to drain accounts. Passwords to email and social media accounts let a hacker impersonate you or lock you out of your own accounts.

Health records are valuable because they contain personal details and insurance information. Business secrets and customer lists can be sold to competitors. Intellectual property—designs, source code, research—can be stolen and used or sold. In some cases, hackers do not steal anything; they just encrypt your files and demand payment to unlock them, a crime called ransomware.

Signs your account or device has been hacked

If you notice you cannot log into an account, your password no longer works, or you see a message saying your password was recently changed—someone else may have changed it. Check your email's login history or recent activity log (most email providers show where and when your account was accessed). If you see logins from places you have never been, your account is compromised.

Watch for unexpected charges on your credit card or bank statement, emails you did not send in your sent folder, or contacts saying they received messages from you that you did not write. Your device may be hacked if it runs slowly, crashes often, shows pop-up ads constantly, or uses a lot of data even when you are not using it. If you see unfamiliar programs installed or your browser homepage changed without your action, malware may be running.

Steps to reduce your hacking risk

Use a strong, unique password for every account that matters—email, banking, social media. A strong password is at least 12 characters long and mixes uppercase letters, lowercase letters, numbers, and symbols. A password manager like Bitwarden or 1Password can generate and store these for you so you only have to remember one master password.

Enable two-factor authentication (also called 2FA) on accounts that offer it, especially email and banking. Two-factor means even if a hacker has your password, they cannot log in without a second proof—usually a code sent to your phone or generated by an app. This stops most account takeovers.

Update your software as soon as updates are available. Turn on automatic updates in Windows, macOS, iOS, and Android so you do not have to remember. Update your apps regularly too, especially browsers and security software.

Be cautious with email. Do not click links or read attachments from senders you do not recognize. If an email from your bank or a company asks you to log in, do not click the link in the email—instead, go directly to the official website by typing the address yourself. Hover over links to see where they actually go before clicking.

Use antivirus or antimalware software. Windows Defender (built into Windows) and Malwarebytes are both solid free options. They scan for known malware and block suspicious files.

What to do if you have been hacked

If you realize your account has been hacked, change your password when ready from a different device if possible. Use a strong, unique password you have never used before. Check your account's login history and remove any sessions or devices you do not recognize.

If your email was hacked, check your recovery email and phone number—hackers sometimes change these to lock you out. Reset them to information only you control. Check your connected apps and services (the page that shows which apps have permission to access your account) and remove anything unfamiliar.

If your financial accounts were hacked, contact your bank or credit card company when ready. They can freeze accounts, dispute fraudulent charges, and monitor for further fraud. Consider placing a fraud alert or credit freeze with the credit bureaus (Equifax, Experian, TransUnion) so no one can open new accounts in your name without extra verification.

If your computer has malware, run a full scan with your antivirus software in Safe Mode (a Windows startup mode that loads only essential programs). If the scan finds nothing but the problem continues, consider wiping the device and reinstalling the operating system, or take it to a repair shop.

Frequently Asked Questions

Can hackers see me through my webcam?

Yes, if malware is installed on your device or if a hacker gains remote access. This is rare but possible. Cover your webcam with tape or a sliding cover, and keep your software updated and antivirus current. Only use webcams on trusted devices and with trusted applications.

Is public WiFi safe to use?

Public WiFi is risky because hackers can intercept unencrypted data sent over it. Avoid logging into banking or email accounts on public WiFi. If you must, use a VPN (virtual private network) like Proton VPN or Mullvad, which encrypts your traffic so hackers cannot see it.

What is the dark web and do hackers use it?

The dark web is a hidden part of the internet that requires special software to access and offers anonymity. Hackers use it to sell stolen data, buy hacking tools, and communicate without being traced. Ordinary people do not need to go there; it is not safer or more private than the regular internet for normal use.

Can my phone be hacked?

Yes. Phones can be hacked through malicious apps, phishing texts, unpatched software, or by connecting to compromised WiFi. Protect your phone the same way you protect a computer: use a strong passcode, enable two-factor authentication, update iOS or Android when prompted, and read apps only from the official App Store or Google Play.

What is a data breach and how is it different from hacking?

A data breach is when hackers successfully steal data from a company's servers. A company might be hacked (broken into) but not suffer a breach (data stolen). When a breach happens, the company usually notifies affected users. You may receive a letter or email saying your information was exposed; if so, change your password and monitor your accounts for fraud.