Just as a virus can be used as a technical term and a health-related term, malware can also be broken down using that analogy.

In the same way, diseases can be categorized into bacteria, fungi, viruses, and prions, so also there are different type of  malware. Malware is the mother name of different kinds of infectious and dangerous software or programs.

Malware (malicious software) is software designed to steal data, destroy files, and damage computer systems themselves. They are designed by cyber hackers.

There are several types of malware, some more dangerous than others. We will learn about 9 types of malware and they include:

Worms

A worm is more like a virus that can self-replicate without a host program and spread without any human interaction. A worm is considered to be a Lonewolf kind of malware. The unique feature worms have over viruses makes them more catastrophic. A worm infects a device via a downloaded file or a network connection before it multiplies and disperses exponentially. Just like viruses, worms can severely disrupt the operations of devices.

Stuxnet is a popular example of a worm that was used on a large scale. It was introduced to Iran’s government via a flash drive.

Trojans

They are disguised as helpful software programs. Once downloaded by unsuspecting users, the Trojan can take control of victims’ systems for malicious purposes. Trojans may hide in games, apps, or even software patches, or they may be embedded in attachments included in phishing emails. 

Emotet is a sophisticated banking trojan and it has been around since 2014.

Rootkits

A rootkit is a type of malware that gives attackers remote control of a victim’s computer with complete administrative privileges. Mostly, they spread through malicious downloads, social engineering attacks, or malicious attachments.

Zacinlo is an example ofo a rootkit that infects systems when users download a counterfeit VPN app.

Ransomware

Being one of the most rampant types of malware, ransomware is malicious software that uses encryption to disable a victim’s access to its own data and demands a ransom (usually in a cryptocurrency) in return to decrypt the encrypted data. Ransomware can be prevented just like any type of malware. However, once it infects a system, an offline backup is usually the only solution (except for paying the ransom) to recover a system. This is because they use well-known and difficult-to-crack encryption schemes to render the data inaccessible to the victim. In rare cases, it could be possible to find implementation faults in the malware through reverse engineering to recover the encrypted data back.

An example is RobbinHood.

Spywares

A spyware is a malicious software that runs secretly on a computer and reports back to a remote user. Rather than simply disrupting a device’s operations, spyware targets sensitive information and can grant remote access to hackers. Spyware is often used to steal financial or personal information. Spyware is not limited to the desktop browser; it can also operate in a critical app or on a mobile phone.

An example is DarkHotel, which targeted business and government leaders using hotel WiFi.

Keyloggers

A keylogger is a type of spyware that monitors user activity. Keyloggers have legitimate uses; businesses can use them to monitor employee activity and families may use them to keep track of children’s online behaviors. However, when installed for malicious purposes, keyloggers can be used to steal passwords, banking information, and other sensitive information.

Olympic Vision has been used to target US, Middle Eastern, and Asian businessmen.

Adware

Adware tracks a user’s surfing activity to determine which ads to pop up. Although adware is similar to spyware, it does not install any software on a user’s computer, nor does it capture keystrokes like keyloggers. The danger in adware is the erosion of a user’s privacy — the data captured by adware is collated with data captured, overtly or covertly, about the user’s activity elsewhere on the internet and used to create a profile of that person. The profile includes what they’ve purchased, where they’ve traveled, and more. That information can be shared or sold to advertisers without the user’s consent.

Fileless Malware

Usually, malware infects and spreads through the file system. Fileless malware, instead of exploiting and spreading in memory only to prevent detection by anti-malware or other security mechanisms. In clearer terms, they exploit initially non-file OS objects such as registry keys or APIs and persist only in the memory to leave few traces as possible on the infected system.

Astaroth is an example of fileless malware.

Viruses

This is the most common known malware type that is capable of infecting other files and spreading to other computers. Once downloaded, the virus will lay dormant until the file is opened and in use. They spread to other computers by attaching themselves to other programs when a user launches an infected program. 

Most malware is not one type in nature, they consist of two or more of the above-explained malware.