Malware is a term used to refer to a wide range of hostile or intrusive software which can take the form of scripts, executable code, active content, or rogue security software. They vary in their purpose, how they infect a computer, how they replicate and the damage or security risk they pose. Here is a list of commmon Malware types:
Virus
Viruses are very varied and there are over 1 million viruses in existence. All attach themselves to an existing program and either replicate themselves when that program is run or modify a program in some way. The main purpose of a computer virus is to corrupt the system or destroy data. They can infect data files, or even the boot sector of the hard drive
Spyware
These are programs that can covertly record what you do on your computer. Some spyware is legitimate and is used to help a user. For example gaining access and viewing another person’s computer screen. Even controlling the curser. However the majority of Spyware is malicious and usually used to capture logins and passwords or even bank or credit card details.
Worms
A computer worm is an independent, self-contained computer program that can replicate itself in order to spread to other files on a computer or other computers within a network. Unlike a virus, a worm does not need to attach itself to an existing program.
Adware
While the least dangerous malware it’s one of the most common. It is also one of the most lucrative in that it downloads and displays unwanted ads that redirect the user to advertiser websites. Benign Adware requests the Users permission before displaying ads while malicious adware does not notify the user or obtain his or her consent.
There are two ways that Adware can infect your computer. This can be via Freeware or shareware and can involve a legitimate way of generating advertising revenue from a program you have downloaded. A second way is from an infected website which can result in unauthorized installation of adware on your machine whereby a hacker can gain access to a browser vulnerability, even placing a Trojan on your computer. These are usually cased Browser Hijackers.
Trojan
A computer Trojan is one of the most dangerous forms of malware due to its ability to deceive users of its true intent, often disguising itself as legitimate software. After a Trojan has infected a computer, they can then be activated and in some cases be used by cyber-criminals to gain backdoor access to a computer and steal sensitive data.
A denial of service attack can also occur when sending multiple requests from your computer and several other infected computers, overwhelming the target address.
Rootkit
These are one of the hardest to detect and remove as they are designed to conceal certain activities or programs on your computer with the main purpose of preventing malicious programs from being detected – thereby extending the time by which a program can run on an infected computer. A rootkit can enable an unauthorized user to gain control of a computer without being detected and can be hard to remove even when using anti-virus software.
Keyloggers
Keyloggers are used to record every keystroke made on a computer, often with the intent of gaining access to logins and passwords or other confidential information. However they are sometimes legitimately used by companies to record an employee’s activity or by parental software.
Ransomware
Ransomware is a type of malicious software designed to lock the system or block access while online. It will often display a message until a sum of money is paid, sometimes appearing as a notification from the police or FBI, or demand money for the removal of a non-existent virus. More advanced Ransomware may encrypt a victims files and make them inaccessible until the user provides a ransom payment to decrypt them.
Browser Hijacker
A Browser Hijacker is malware that changes your browser’s settings, often redirecting you to a different website. Usually this involves changing your homepage or search engine without permission. The purpose is usually to force traffic to a particular website, thereby generating revenue. Some Browser Hijackers can install a software keylogger to gather unauthorised information or they can damage the Windows registry.
Rogue security software
This is software designed to appear like legitimate security software and misleads users into believing their computer is infected with a virus, with the intent of tricking them into paying money for a fake malware removal tool. The fake malware removal tool can even introduce real malware onto the computer
