Malware facts for kids
Malware is short for malicious software. It is a type of software that can get onto a computer without the owner's permission. Malware can harm computers in many ways. It includes things like viruses and Trojan horses.
Other harmful programs like spyware and ransomware are also malware. These programs can steal passwords or delete important files. They might collect your personal information. Sometimes, they can even stop your computer from working at all.
Computer security or anti-malware programs usually help stop malware. If you do not have security software, malware can easily get onto your computer. Once it is there, getting rid of malware can be very hard. Even special removal programs might struggle.
The word "malware" only means software made to cause harm. It works against what users expect. It does not include programs that cause problems by accident.
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History of Malware
People started creating malware in the 1970s and early 1980s. Computers back then were quite simple. They did not have much interesting information to steal. People often wrote malware just for fun. They also made it to show what they could do.
Most malware from this time did not damage computers. In fact, malware was so rare that the word "malware" was not even invented until 1990.
More people began using computers in the late 1990s and early 2000s. Computers also became much more complex. People then realized they could use malware to steal useful information. This included passwords and credit card details. So, more programmers started writing malware.
The number of malware programs on the internet has grown very fast since the late 1990s. It is still growing today. Experts believe that about 31.5% of computers worldwide have some type of malware.
Why People Create Malware
The main reason people create malware is to hurt others. They also do it to make money. This is usually done by stealing or deleting important information.
For example, the Cryptolocker computer virus locks your computer. You cannot use it until you pay the malware creators. They then give you a software key to unlock it. Another virus, CIH, tries to make your files unusable. It can also stop your computer from turning on again.
Malicious keystroke logging software records everything you type. It then sends this information to the malware creator.
Some governments have even created malware to harm their enemies. Experts think the United States government made a virus called Stuxnet. It was designed to stop an important place in Iran from working. The Chinese government may have used a virus to stop people from protesting.
How Malware Spreads to Computers
Malware can get onto someone's computer in many ways. One common way is through email attachments. These attachments often come from other computers that are already infected. When you download and open the attachment, the virus installs itself. It then uses your computer to send itself to even more people.
Another way malware installs itself is called drive-by downloading. This happens when you visit a website that has malware hidden on it. You do not have to click anything for your computer to get infected. This type of attack is often found on less popular websites. It can also be on sites with old security methods. However, even popular websites can host drive-by downloads if a hacks the site.
Malware creators also attach their programs to real software that people want. This is most common with pirated programs. People who download pirated software cannot complain to authorities. This is because they were doing something illegal themselves.
Some legal websites also bundle malware with real software. This is called "bundling." Computer security experts often complain about these websites. However, their complaints do not always stop the bundling.
Types of Malware
There are many different kinds of malware. Each one acts in its own way.
- Viruses need a program run by a user to work. They cannot copy themselves or move between computers alone. They need a host program. Viruses are very common in pirated software. They can harm computers in many ways. This includes deleting files and stealing passwords.
- Worms are similar to viruses. They can cause the same kinds of damage. However, worms can move through the internet and copy themselves. They do not need a host program. This makes them more dangerous than viruses. Worms are often found in emails and drive-by downloads.
- Trojan horses pretend to be normal, useful programs. They trick you into installing them. A Trojan horse usually has a hidden harmful function. This function activates when the program starts. They need a user to agree to run them. They cannot copy themselves to other computers. However, Trojan horses can cause the same problems as viruses. They can also let the malware creator control your computer. They might install more malware or steal bank data. For example, ransomware is a type of Trojan horse. It stops you from using your files until you pay the person who wrote it. Experts believe Trojan horses are the most common type of malware.
- Adware makes money for its creators through advertising. These programs show you ads. They also force you to use websites that earn money for the malware writers. Adware can also find personal information about you. This includes your age, race, and job. The malware creators then sell this information to others. You can usually uninstall adware more easily than other malware. But it can still be hard without a special program.
- Spyware is a more dangerous type of adware. It steals more information from you. Spyware can steal your internet traffic. It can also steal account passwords. It can even record anything you type on your computer. Spyware is much harder to uninstall than adware.
Why Computers Get Malware
Computers can get unwanted programs for a few reasons. One common reason is because of software bugs in regular programs. Malware can use these bugs, like a buffer overflow. This makes a program do something it was not designed to do.
Malware can also get onto a computer by tricking you into installing it. This can happen if you plug in a USB flash drive that already has a virus. Malware also often uses social engineering to trick users. For example, it might pretend to be an important email attachment for work. Some malware even pretends to be an anti-malware program. It does this to get people to run it.
How Malware is Stopped
Malware is a big problem. Many companies create programs to try and stop it. These anti-malware programs have different ways to find malware.
One way is static analysis. This method looks at the source code of a program before it runs. If the program looks like malware the static analysis program has seen, it stops the code. Another way to find malware is dynamic analysis. Dynamic analysis runs only part of a program it is checking. If this part tries to do anything harmful, the anti-malware program will stop it.
Malware can also be stopped without a program. You can do this by not letting a computer connect to the internet or other computers. This is called creating an air gap. However, these computers can still get malware. This happens if someone puts it there another way. For example, if someone plugs in a USB drive that was already in an infected computer.
See also
In Spanish: Malware para niños
