1. Computer safety
Filip Hruby

2. Virus
A computer program usually hidden within another seemingly innocuous program that produces copies of itself and inserts them into other programs or files, and that usually performs a malicious action (such as destroying data).

3. Trojan horse
Trojan is any malicious computer program which misrepresents itself to appear useful, in order to persuade a victim to install it.
Trojans are generally spread by some form of social engineering. Although their payload can be anything, many modern forms act as a backdoor.
While Trojans and backdoors are not easily detectable by themselves, computers may appear to run slower due to heavy processor or network usage.
Trojans generally do not attempt to inject themselves into other files.

5. Rootkits
Once a malicious program is installed on a system, it is essential that it stays concealed, to avoid detection. Software packages known as rootkits allow this concealment, by modifying the host's operating system so that the malware is hidden from the user. Rootkits can prevent a malicious process from being visible in the system's list of processes, or keep its files from being read.

6. Worms
A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers
Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it.
Unlike a computer virus, it does not need to attach itself to an existing program.

7. Backdoors
A backdoor is a method of bypassing normal authentication procedures, usually over a connection to a network such as the Internet. Once a system has been compromised, one or more backdoors may be installed in order to allow access in the future, invisibly to the user.
Backdoors may be installed by
Trojan horses, worms, implants,
or other methods.

8. How to prevent malware
Use an antivirus program – Good examples are: Microsoft Security Essentials, Avira, Malwarebytes.
You don’t need a antivirus program if you don’t go on any malicious websites.
Use strong passwords
Use two step authentication
Don’t download any files of unknown origin

9. The End
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