The term malware is a portmanteau of the words malicious and software and it denotes any piece of software that is used to cause harm to someone else’s computer, device or system. This entails compromising a device’s functions, stealing data and bypassing access controls, among other things, mostly for financial gain, but for other purposes as well. The following are the most common types of malware that users face today.
Viruses are among the oldest types of malware and they got their name thanks to their similarity with biological viruses. Namely, this type of malware is capable of multiplying and spreading to previously uninfected computers and systems. Most commonly, viruses attach themselves to other software and activate once the infected software is executed. They are also able to spread via documents, script files and scripting vulnerabilities in apps.
Viruses are used for a number of purposes, including stealing information, creating botnets, stealing money, and harming networks and computers.
Worms are another “traditional” form of malware that is very common. They exploit the vulnerabilities in operating systems and spread over various computer networks. They consume bandwidth and overload web servers, thus harming the networks in question. They can also be used as “payload” carriers that can spread all over the network and deliver those payloads to targeted computers or subsystems. The main difference between worms and viruses is that worms do not require user action to spread and activate.
Trojans, which are officially called Trojan horses, assume the appearance of regular programs or files so that the user would download them without suspecting anything. Attackers use them to gain remote access to your system. They can steal data, install additional malware and monitor everything the user does on the infected computer.
Adware is a malware type that is used to automatically deliver advertisements. Everyone has had experience with pop-up ads or advertisements that come as part of certain software. That is adware. In more “malicious” cases, adware comes combined with spyware (described below) in these so-called adware/spyware bundles that can track user activity as well as steal information.
As its name suggests, spyware is malware which spies on the activities of users without letting them know. This can include collecting keystrokes (what is being typed), data harvesting and simple activity monitoring. Spyware can also modify security settings and interfere with network connections. Spyware often bundles itself with perfectly legitimate software.
A rootkit is malware which is used to remotely access a computer and even control it without the user or their security measures becoming aware of its existence. Once the computer is infected by rootkit, the malware starts “hiding” itself and executing other operations, allowing the attackers to alter software (often security software), steal data, execute files, modify configurations of the system, install additional malware and use the computer as part of a botnet.
Bots are everywhere you look and the majority of them are created with perfectly legal purposes in mind, such as online contests, Internet auctions and so on. However, bots can also be used for illegal purposes, often combined in remotely-controlled botnets which are then used for DDoS attacks. They can also be used to scrape server data, distribute malware and render advertisements on websites.
Ransomware is a relatively new form of malware that entails an added layer of illegality, so to say. Namely, when a computer is infected with ransomware, its functions or data are being held captive by this malware. The user then has to pay the malware creator in order to get back control or access to their files or functions. Ransomware usually spreads like worms.
The Importance of Anti-Malware Software
Consider all these threats and the harm they can do to your computer, it is absolutely essential that you install the most comprehensive anti-malware and anti-virus software. Closing your eyes and hoping for the best will simply not do anymore.