Malware is malicious software, an application that is built with the sole purpose of compromising computers, either stealing data from them, or damaging them. The article will discuss the most common types of malware.
VIRUSES
Believe it or not, the first self-replicating virus was created by a company – BBN Technologies – back in 1971. Modern viruses are much more advanced, of course, being able to attach their code to other applications, and then infect any storage device, including USB memory sticks, external hard drives, and so on. Most virus makers use their creations to steal other people's financial information, create remote-controlled botnets, display unsolicited advertisements, etc.
ADWARE
This type of malware is not that aggressive, but it doesn't mean it's welcome on our computers. Adware creators build applications which display pop-ups and ads that earn them money whenever we click them.
Sadly, many high-quality freeware programmers incorporate adware in their future application versions, after they have amassed a large user base. So, to be safe, don't install any freeware without reading its users' reviews first, thus making sure that the application is free from adware.
RANSOMWARE
Search our blog and you will find an article that's dedicated to ransomware, one of the most dangerous species of malware. In a nutshell, ransomware sneaks into your computer using an infected website or application, and then starts encrypting the data on your PC.
When the process ends, the program displays a warning, asking for a ransom (usually in a bitcoin account) in exchange for the data decryption key. Sadly, most malware creators won't send anything in return for your hard-earned cash, so you'll have to format the entire drive and reinstall the OS and applications anyway.
ROOTKITS
These malware pieces are advanced viruses which can bypass the protection that's provided by the operating system and the installed antiviruses, by loading their code into the memory before the OS loads its modules.
There are a few dedicated applications which can detect rootkits, such as Kaspersky's TDSSKiller, and many modern antiviruses can deal with rootkits as well. If your computer is infected with one of these terrible pests, it's best to boot it using a rootkit scanning tool that's been copied to a DVD or memory stick; this way, the risks of having the malware load in the background are reduced to zero.
SPYWARE
If you think that spyware spies on computer users' activity, well... you are right! This malware variety will try to monitor your actions, logging any keystroke, the visited websites, taking screenshots of your activity every few seconds, and sometimes even recording videos of it!
As you can imagine, all this information is then silently and secretly uploaded to the malware creator's server, where it is analyzed carefully. Those cyber criminals are especially interested in harvesting financial data and account logins, of course.
TROJAN HORSES
Just like the horse that was utilized in the Trojan War, this piece of malware tries to mislead computer users. People are convinced to open an email attachment that doesn't look suspicious, for example, or to click a normal looking ad. Still, this seemingly innocent action will trigger an infection with dangerous malware; most ransomware programs are installed by making use of a trojan horse, which can spread quite fast through social engineering (i.e. psychological manipulation), especially on social media websites.