Some of the more commonly known types of malware are viruses, worms, Trojans, bots, ransomware, backdoors, spyware, and adware. In addition to damaging data and software residing on equipment, malware has evolved to target the physical hardware of those systems.
Malware should also not be confused with defective software, which is intended for legitimate purposes but contains errors or "bugs. Two of the most common types of malware are viruses and worms. These types of programs are able to self-replicate and can spread copies of themselves, which might even be modified copies.
To be classified as a virus or worm, malware must have the ability to propagate. The difference is that a worm operates more or less independently of other files, whereas a virus depends on a host program to spread itself. These and other classes of malicious software are described below. Ransomware is a type of malicious software that threatens to publish the victim's data or perpetually block access to it unless a ransom is paid. While some simple ransomware may lock the system in a way that is not difficult for a knowledgeable person to reverse, more advanced malware uses a technique called cryptoviral extortion , which encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them.
A computer virus is a type of malware that propagates by inserting a copy of itself into and becoming part of another program. It spreads from one computer to another, leaving infections as it travels. Viruses can range in severity from causing mildly annoying effects to damaging data or software and causing denial-of-service DoS conditions. Almost all viruses are attached to an executable file , which means the virus may exist on a system but will not be active or able to spread until a user runs or opens the malicious host file or program.
When the host code is executed, the viral code is executed as well. Normally, the host program keeps functioning after it is infected by the virus. However, some viruses overwrite other programs with copies of themselves, which destroys the host program altogether.
Viruses spread when the software or document they are attached to is transferred from one computer to another using the network, a disk, file sharing, or infected email attachments. Computer worms are similar to viruses in that they replicate functional copies of themselves and can cause the same type of damage.
In contrast to viruses, which require the spreading of an infected host file, worms are standalone software and do not require a host program or human help to propagate.
To spread, worms either exploit a vulnerability on the target system or use some kind of social engineering to trick users into executing them. A worm enters a computer through a vulnerability in the system and takes advantage of file-transport or information-transport features on the system, allowing it to travel unaided. More advanced worms leverage encryption, wipers, and ransomware technologies to harm their targets.
A Trojan is another type of malware named after the wooden horse that the Greeks used to infiltrate Troy. It is a harmful piece of software that looks legitimate. Users are typically tricked into loading and executing it on their systems. After it is activated, it can achieve any number of attacks on the host, from irritating the user popping up windows or changing desktops to damaging the host deleting files, stealing data, or activating and spreading other malware, such as viruses.
Trojans are also known to create backdoors to give malicious users access to the system. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate.
Trojans must spread through user interaction such as opening an email attachment or downloading and running a file from the Internet. Bots often automate tasks and provide information or services that would otherwise be conducted by a human being.
They may also be used to interact dynamically with websites. Bots can be used for either good or malicious intent. In addition to the worm-like ability to self-propagate, bots can include the ability to log keystrokes, gather passwords, capture and analyze packets, gather financial information, launch Denial of Service DOS Attacks , relay spam, and open backdoors on the infected host. Bots have all the advantages of worms, but are generally much more versatile in their infection vector and are often modified within hours of publication of a new exploit.
They have been known to exploit backdoors opened by worms and viruses, which allows them to access networks that have good perimeter control. Bots rarely announce their presence with high scan rates that damage network infrastructure; instead, they infect networks in a way that escapes immediate notice.
Advanced botnets may take advantage of common internet of things IOT devices such as home electronics or appliances to increase automated attacks. Crypto mining is a common use of these bots for nefarious purposes. Advanced malware typically comes via the following distribution channels to a computer or network:.
A set of stealthy and continuous computer hacking processes, often orchestrated by a person or persons targeting a specific entity. An APT usually targets either private organizations, states, or both for business or political motives. For example, the detection for the variant ". AF" would have been created after the detection for the variant ". Provides extra detail about the malware, including how it is used as part of a multicomponent threat.
In the example above, "! Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Virus : A virus is a malicious executable code attached to another executable file that can be harmless or can modify or delete data. When the computer program runs attached with a virus it performs some action such as deleting a file from the computer system.
Difference between Worms and Virus : S. A Worm is a form of malware that replicates itself and can spread to different computers via Network.
A Virus is a malicious executable code attached to another executable file which can be harmless or can modify or delete data. The main objective of viruses is to modify the information.
It requires a host is needed for spreading. It is less harmful as compared. It is more harmful. Worms can be detected and removed by the Antivirus and firewall. Antivirus software is used for protection against viruses. Worms are executed via weaknesses in the system. Viruses are executed via executable files.
Boot sector virus, Direct Action virus, Polymorphic virus, Macro virus, Overwrite virus, File Infector virus are different types of viruses 9.
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