For many people, the first thing that comes to mind when discussing the term ‘malware’ or internet security as a whole is the computer virus. This is quite the common misunderstanding, as in reality viruses are only a subdivision of the much larger class of security threats that malware represents. The term ‘malware’ originates from the words malicious software and it refers to all kinds of hostile code, executable scripts, programs and software that are designed with the goal of attacking the victim’s software with malicious intent. However, nowadays one differentiates between various types of malware, each created with its own purpose and methods of inflicting harm.
Nowadays, adware is one of the most heavily used types of malware. One of the main reasons for that probably lies in its low threat level, and subsequent low detection rate. Adware is defined as a program that displays some form of advertisement on the affected device. The most common types of adware appear in the form of popups windows. Adware affects not only computers but mobile devices as well.
As can be concluded from the name of the term, spyware is malware that is designed to secretly gather information about the victim’s activities on their device. The victim is then flooded with adware with content chosen according to the previously gathered data about the victim’s personal interests and hobbies, or the data is collected and sold off to third parties.
Viruses are probably the most famous kind of security attack with their origin dating back to the very early stages of computer development. The main characteristic of viruses that distinguishes them from other types of malware is the fact that viruses are made to replicate themselves as many times as possible. Viruses are typically hard to detect, unless a special software (anti-virus program) is used. Typically, viruses are attached to other files in the system, which makes it easier for them to remain hidden.
Like viruses, worms are also a software that counts on contagious strategy to do its evil deeds. Unlike viruses, worms have no need to be attached to other files or programs as they are standalone programs themselves. Usually, worms destroy all the data they find on a hard drive.
The Trojan horse received its name as a reference to the Ancient Greek mythology of the Trojan horse that was used in the battle for the city of Troy. Like in the original story, the software Trojan horse is normally disguised as an innocent program that does its damage when it’s installed and activated on the victim’s computer. Trojans are typically used to gather access to the system or to extract sensitive information from the affected device.
Often, malicious programs rely on the fact that they are hard to detect, and it is essential for them to remain hidden from the user for as long as possible. Because of this, the creation of rootkits was needed. Rootkits are used to conceal whatever actions the malware is performing and prevent the system from detecting the breach in time.
Keyloggers are typically used to extract valuable information like passwords or credit card details. This type of malicious software is used to record all of the keystrokes that are entered from the keyboard and then forward the typed information to the attacker.
Rogue Security Software
Rogue Security Software usually operates as a disguised version of anti-malware software. It takes advantage of deceiving the user that it is software built with good intentions, and when installed on the computer, usually blocks the functions of the real anti-malware.
For many, ransomware is the harshest of all computer threats there are. Usually, the attacker gains sole access to the victim’s data and threatens to publish, destroy, or exploit it. A popular method is to lock the affected device by encrypting the hard drive and thus, making the computer useless. As the name suggests, the goal of this attack is to extract a ransom in exchange for unlocking the data that is held hostage. Unfortunately, there is no guarantee that paying will lead to receiving the stolen information back.
A browser hijacker is a type of malware that subtly changes the settings of the victim’s web browser. As a result, the home page of the victim can be changed with a new one chosen by the attacker, adware/spyware or even keyloggers can be installed.