12 Types of Malware Attacks (Including Examples + Prevention Strategies)

Updated Dec 2, 2022.
Types of Malware Attacks

Every IT security expert and the regular system user must be concerned about malicious software's dangers.

Many businesses' IT security infrastructure is weak. The strategy deployed to prevent malware from accessing their personal and business information often involves installing an anti-virus and forgotten about it.

No anti-virus, anti-malware, or security software can guarantee 100% protection from malware. The starting point to preventing malware attacks is to know about the different types of malware.

This article will examine 12 types of malware and their best prevention strategies to keep your information safe and secure.

Let's get started.

What is Malware?

Malware is malicious software designed to infiltrate a computer. This unauthorized infiltration can result in either temporary damage, one that you can easily reverse, or permanent and more lasting damage to the infected computer system in extreme cases.

Total Malware
Source: AV-Test

Cyber attackers design the malicious code called malware as sophisticated malware attacks to gain unauthorized access to computer systems, steal vital data from the victim's computer, and encrypt files on the infected systems.

The damage a malware is likely to cause largely depends on the malware that afflicts the system. To a large extent, the level of exposure plays a huge role in determining how much damage is likely to be incurred.

76% of cyber attacks are financially motivted
Source: Safety Detectives

Common Types of Malware

Malware exists in different forms and types, each with unique traits and characteristics. Each type leverages phishing and social engineering attacks to infect devices and deliver malware to its victims.

Polymorphic malware uses an encryption key to regularly change its recognizable features to evade detection by antivirus programs.

With the strengthening of the counter-measures to detect and remove malware completely, some malware types have modernized to become hybrids of one another to strengthen their resolve further.

Cybercriminals now spread malware using physical and virtual means to carry out cyber threats.

Here are some of the common malware types and their malicious intent.

1. Spyware

This type of malware is best known for infiltrating the victim's system without their knowledge and readily gathering and transferring sensitive information to the mastermind behind the attack.

By collecting sensitive data such as the victim's internet data usage, passwords, credit card information and pins, and bank account information, spyware aims to sell this personal information on the dark web.

Spyware can install additional unpatched software to change key settings on the victim's system and open them up to a load of vulnerabilities.

With its application not limited to a desktop browser, spyware can operate on mobile devices. Unlike other malware types, spyware is easy to remove as it is not nefarious. You can use the best anti-spyware software to protect against spyware attacks.

What Is Anti-Spyware Software

Spyware Example

An example of spyware in action was the DarkHotel, which was designed to identify and target businesses and government officials via a hotel WIFI to gain access to the systems of these influential individuals.

2. Adware

Similar to spyware, adware does not install nor capture any software on a user's computer. Adware is a special type of grayware or unwanted software designed as an advertisement or pop-up on the user's web browser screen to track their surfing activity.

One of the most profitable and least harmful forms of malware, adware works by eroding a user's privacy to illegally create a user profile based on their activities on the internet.

The danger is that this collated information can be shared or sold to advertisers without the user's permission.

The most common adware
Source: Dr.Web News

Adware Example

An example of adware is the fireball that found its way to infect over 250 million computers in 2017 by simply hijacking their browsers and changing their default search engines to provide room for the hackers to track their web activity and have a remote control.

3. Ransomware

Unlike other malware types, ransomware is software that uses encryption to restrict and disable a target user's access to their computer system or data until a defined ransom is paid.

By rendering the user partially or unable to carry out basic activities on their system, hackers hold their victims hostage with the promise of a decryption key once the ransom conditions have been met, which is often in the form of cryptocurrency for anonymity.

Ransomware attacks lead to downtime on the victim's part and a series of data leaks and breaches. It has been observed that these ransomware attacks spread through phishing emails and exploiting software vulnerabilities, among other methods.

Common Industries Targeted by Ransomware Q1 2022
Source: Coveware

Ransomware Examples

Ransomware named RobbinHood hit the city of Baltimore, which was designed to disrupt key government accounting procedures, including collecting taxes and transferring properties. It led to city activities being grounded for weeks as government emails were also affected.

According to estimates, this ransomware-type cost the city of Baltimore more than $18 million in revenue for the weeks they grounded city activities.

Another example of a notorious ransomware attack was the WannaCry attack in 2017, designed to target thousands of systems worldwide using the Windows OS.

The attack affected several corporate business networks that had to retrieve their compromised data via anonymous bitcoin payment.

Randomware statistics by the numbers
Source: Forbes

4. Fileless Malware

Fileless malware is a type of malware disguised as legitimate software programs to carry out the cruel act of infecting a computer.

Unlike other types of malware, fileless malware, as the name implies, does not install its malicious link or files but uses an existing, legitimate program to alter known to the user's operating system.

The fileless malware leaves no footprint, making it difficult for antivirus software to track and remove malware. It uses the fact that the user's operating system would recognize the edited files as legitimate and would not flag them until the damage has been done.

This malware is designed to work in memory. It has a relatively higher success rate than its other traditional malware counterparts as it is largely resistant to many anti-malware forensic strategies, including signature-based detection tools.

Characteristics of a Fileless attack
Source: TrendMicro

Fileless Malware Examples

Astaroth, Frodo, Number of the Beast, and the Dark Avenger are the common and most notable examples of fileless malware that have occurred various times.

The most recent fileless malware witnessed was the Equifax breach, where the Democratic National Convention was the victim.

5. Trojan Horse

Trojan horses are malware disguised as legitimate programs to deceive users of their true intention.

The name was derived from the popular Ancient Greek story of the deceptive Trojan horse that brought about the fall of the city of Troy.

You can spread this malware with social engineering methods such as phishing. This malware disguises an infected file as an executable file that contains the Trojan horse to be installed.

By acting as a backdoor, Trojan gives the attacker remote control to access sensitive information of the users.

Unlike computer viruses and worms, Trojan does not seek to inject malicious code into the infected files to reveal its operation. They are common in games, apps, software patches, or embedded as attachments in phished emails.

Trojan Horse Example

Emotet is one of the popular and most notorious examples of Trojan horse malware which is estimated to cost governments to remediate about $1 million per incident.

Designed as a sophisticated banking Trojan, Emotet is flagged as a visible threat by the US Department of Homeland Security due to its persistency in evading signature-based detection.

6. Computer Worm

A worm is a self-replicating malware program that feeds mainly on vulnerabilities in operating systems to attach itself to a system's network. During self-replication, the worm maintains active status on the network of the infected system.

Worms can access a system's network through backdoors built into the software, intentional software vulnerabilities, or external storage devices such as flash drives.

Once the worm has gained access to a system's network, threat actors use these malicious actors to launch coordinated attacks to steal sensitive information and data or for a broader malware strike.

Unlike viruses, the degree of damage caused by worms to a computer network is relatively minimal. The damage might be in the form of bandwidth consumption compared to viruses that corrupt and modify files on the victim's system.

Although most worms are designed to only spread without directly changing the systems they come in contact with, some other worms can cause major disruptions.

Computer Worm Examples

Examples are the Morris Worm and Mydoom, which usually cause large disruptions resulting in increased malicious traffic.

Another example of a worm in action was the SQL Slammer that terrorized its victims in 2003 by exploiting vulnerabilities in Microsoft's SQL server software.

Although this malware attack only lasted about 10 minutes, it is still regarded as one of the fastest spreading worm malware ever created. WannaCry and Stuxnet are other notable examples of computer worms.

Outbreak - the first five victims of the stuxnet worm
Source: Threatpost

7. Computer Virus

A virus is a type of malware that works on self-replication by inserting itself and then modifying other computer programs via its code. Upon the success of the replication process, the area in contact with the virus becomes infected.

Using social engineering to exploit system vulnerabilities, threat actors use computer viruses to infect a system to spread the virus.

Operating systems of a system are usually the target of many viruses that use complex anti-detection tactics to avoid being caught by antivirus software.

The effect of computer viruses on the world economy has been pegged at several billions of dollars worth of economic damage due to system failure, wasted resources, and increased maintenance costs.

Besides the economic ramifications of viruses, they can be a tool to steal sensitive data such as credit card information and launch coordinated DDoS attacks or malware attacks.

A key difference between a virus and a worm is that the former needs a host program to function while the latter can function independently of a host program.

Difference between Virus and Worm
Source: Byju’s

Computer Virus Example

An example of a real-world malware virus was the ILOVEYOU virus of 2000. This virus got hold of millions of its victim's systems by disguising it as a malicious email with the content “ILOVEYOU.” Any user that downloaded the attachment file fell prey to this malware virus.

8. Rootkits

A rootkit is a collection of malware that gives malicious hackers remote control of a user's computer or key segments of a software program with full administrative capabilities. They are directly installed or automated into applications, kernels, hypervisors, or firmware.

Rootkit's access is obtained and can be spread through a direct attack on the system, phishing, malicious downloads and attachments, exploiting vulnerabilities, or compromised shared drives. It can serve as an effective means to conceal the presence of other types of malware.

Removing malware such as the rootkits is difficult and, in most cases, practically impossible as it subverts the system's antivirus program, making it difficult to find it.

In cases where the rootkits have made their way into the kernel or firmware, a replacement of the hardware or specialized equipment of the system is often required.

How to Detect and Remove Rootkit
Source: Spiceworks

Rootkits Example

Zacinlo is a typical example of rootkit malware. It works by infecting a user's system by disguising it as a fake VPN app. Zacinlo offers payload to malicious actors as a cut of the commission from ads clicked on by the malware in the invincible browsers created.

9. Malvertising

Quite contrary to adware, malvertising is malware that disguises as ads on legitimate websites. Both malvertising and adware use online advertising to carry out their attacks.

Advertising has proven to be one of the most effective means of spreading malware. It occurs because significant considerations and efforts are put into making these malicious ads attractive to users.

Malvertising malware works by preying on the popularity and reputation of legitimate websites to carry out their ferocious attacks.

Malvertising Example

The media malvertising malware attack of 2016 is an example of the malvertising malware in action. Unknowingly, the New York Times, BBC and AOL, and a host of other news sites opened up their list of readers to cyber-attack by serving malvertisement disguised as ads.

10. Keylogger

Despite having numerous benefits to organizations and businesses, ranging from effective monitoring of employee activity and parents being able to track and monitor the activities of their children in the digital space, keyloggers can serve as a malware tool in the wrong hands.

A keylogger is non-sophisticated spyware that tracks and monitors user activity by keeping tabs on each keystroke inputted on a user's specific computer keyboard.

The information gathered is then sent to the attacker, who then scrutinizes this information seeking sensitive and compromising user information such as login credentials and credit card details.

Besides desktops, keyloggers plague mobile phones through phishing, social engineering, or malicious downloads. They are readily on the dark web for a mere $25, which makes them very accessible to malicious actors.

Protect Yourself from Keylogging
Source: Norton

Keylogger Example

Olympic Vision was a notorious keylogger that targeted US, Middle Eastern, and Asian business people seeking to compromise their business emails.

Using spear-phishing and social engineering tactics, Olympic Vision infects its target victim's system to steal sensitive data and spy on their business transactions.

11. Bots/Botnets

By acting like a spider, a bot as a malicious program crawls the internet, looking for vulnerabilities in security infrastructures to exploit. A bot performs automated tasks on commands, and hackers use this malware to get the hack done automatically.

Bots have numerous legitimate functions, such as indexing search engines and various other functions but can be used for malicious purposes in the wrong hands.

In the form of self-propagating malware, bots function by connecting directly to a central server to carry out their attack.

Bots used in large numbers make up a botnet that works on gaining access to devices via malicious codes. Botnets directly hack devices and give hackers remote access to launch coordinated attacks.

Unlike other types of malware, botnets are expansive and cover much ground in so little time, making them very deadly.

They serve as effective methods for distributing Denial of Service(DDoS) attacks, spreading keylogger, ransomware, and a host of other types of malware.

Countries which host the most botnets
Source: Hacker Combat

Botnet Examples

The Mira IoT botnet ranged from 800,000 to over 2.5 million computers infected. It was one of the examples of botnets used to carry out coordinated DDoS attacks on systems.

Another notable mention of the botnet malware is the Echobot which came as a variant of the popular Mirai malware. Echobot was designed to attack many IoT devices while exploiting over 50 known vulnerabilities.

This botnet malware affects Oracle WebLogic Server and VMWare's SD-Wan networking software to launch DDoS attacks, interrupt supply chains, steal sensitive supply chain information, and conduct large-scale corporate sabotage.

12. Mobile Malware

Attacks on mobile devices have risen by more than half over the past years as mobile malware is now leading the charge and becoming more popular among other types of malware. This malware type is as ferocious as its desktop counterparts.

Trojans, Ransomware, advertising links fraud, and a host of others are notable examples of malware that affect mobile phones and computer systems. Similar to desktops, it is distributed through phishing and malicious downloads.

Mobile malware targets vulnerable phones (iOS and Android phones) that lack the basic default protections incorporated in the devices' operating systems to shore their defense against this malware.

Mobile Malware Example

An example of malicious mobile programs that affected mobile devices was the Triada.

The Triada was a rooting Trojan that was injected into the supply chain of millions of Android devices. These infected devices were shipped and distributed with the pre-installed malware program.

Triada works by gaining access to sensitive information and areas in the operating system of the infected devices and installing spam apps on them. These spam apps now override legitimate ads and replace them with malicious ads.

This malware was very profitable for their developers as they could divert the revenue from these legitimate ads into their coffers as their malicious ads were on display on the infected mobile devices.

Malware Detection and Removal Strategies

In counteracting the effect of a well-coordinated malware attack, it is important to ensure the counter strategies and prevention tactics employed are also well coordinated.

These detection and elimination strategies ensure the malware identified is completely exterminated from the affected computer networks.

Here are some of the best malware detection and removal strategies to impede further malware spread for effective malware removal.

1. Install a Multi-Factor Authentication System

Using a multi-factor authentication system helps further bolster the security of your system by adding an extra layer of security. This additional layer of security can either be in the form of a verification code mechanism or a biometric scan.

A multi-factor authentication system is one of the easiest ways of reducing the likelihood of identity theft, as only the users whose data can be identified are granted access to the system.

2. Avoid Malicious Links, Sites, and Emails

A large part of being cyber-conscious requires you to stay suspicious. It is necessary to be alert as, most often, unsuspecting users fall victim the most to malware attacks.

Cybercriminals use malicious advertising to catch the attention of their ready prey to their often suspicious malware camouflaged as links and files that you can easily download.

By being suspicious at all times, you can depict suspicious attachments from unknown sources and avoid them. Security awareness training teaches you to avoid suspicious and malicious links, sites, files, and emails.

3. Regularly Update Your Software

Some software updates are designed to deal with various lapses identified in the security system to make the software more secure.

You are better protected from software vulnerabilities by regulating updating your computer software and programs as new updates arise.

Software updates are configured to identify and provide an immediate solution to vulnerabilities threatening user privacy and safety.

4. Use an Effective Antivirus Software

Although most malware infections show up with some signs that indicate their presence, these signs are often ignored or unnoticed at the least.

Signs such as a sluggish system and a slow booting process are some of the telling signs that indicate the presence of a malware virus.

Antivirus or anti-malware software acts as the perfect antidote to this universal problem. An antivirus software tool is designed to help monitor, prevent and eliminate the occurrence of a series of malware threats.

Using antivirus or anti-malware software alongside your system is one of the most effective malware detection and removal strategy.

Anti-Malware Market for Windows is Still Wide open
Source: Statista

5. Regularly Backup Files

A data backup's main aim is to secure the importation of data or information further. This particular strategy comes in handy in the occurrence where the malware has already been rooted into the system and has sown malicious files into your system. With a file backup system in place, the system is less likely to suffer from data loss as the data saved are usually free from the infected files.

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Martin Luenendonk

Editor at FounderJar

Martin loves entrepreneurship and has helped dozens of entrepreneurs by validating the business idea, finding scalable customer acquisition channels, and building a data-driven organization. During his time working in investment banking, tech startups, and industry-leading companies he gained extensive knowledge in using different software tools to optimize business processes.

This insights and his love for researching SaaS products enables him to provide in-depth, fact-based software reviews to enable software buyers make better decisions.