Malware is an ever-rising threat to information technology security. Understanding the different types of malware is essential to better equip IT specialists and security professionals in their fight against various forms of malicious software. In this blog post, we’ll provide a comprehensive overview of the 16 most common types of malware and brief descriptions to help you identify them and address potential cyber threats.
Figure 1 – The Image Depicts Various Types of Malware
Phishing attacks are fraudulent emails, text messages, phone calls, or websites designed to manipulate people into downloading malware, sharing sensitive information, or taking other actions that expose themselves or their organizations to cybercrime.
Bulk email phishing is the most common type of phishing attack. A scammer creates an email message that appears to come from a large, well-known legitimate business or organization. And sends the message to millions of recipients. The victim clicks on a malicious link or file, and the malware is downloaded to their device.
Types of Phishing
Impact on Businesses
Despite being one of its oldest tactics, phishing is an effective method for cybercriminals to access organizations. However, even though these attacks continue to work today, most enterprise risk management (ERM) and cybersecurity solutions must prioritize phishing detection and mitigation more.
Vishing is a term that combines “voice” and “phishing” to describe a scam that relies on either mobile devices or landline phones. These attacks usually come as a phone call that sounds urgent or alarming. An unsolicited caller tells you your bank account has been compromised and that they need your PIN to verify your identity or unlock the account.
Vishing is an especially insidious cybercrime, because the criminal callers often use threatening language to convince people they could get in serious trouble if they don’t follow the instructions (including legal action or arrest).
Types of Vishing
There are almost an endless number and types of Vishing scams. Criminal callers could pretend to be from your bank to get personal information. They could pretend to be from the IRS to collect money.
Enrollment scams include criminals posing as representatives for government programs, such as the Social Security Administration or Medicare, and managing personal or financial information under the guise of helping you enroll or receive payments.
A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt the regular traffic of a targeted server, service, or network by overwhelming the target or its surrounding infrastructure with a flood of Internet traffic. From a high level, a DDoS attack is like an unexpected traffic jam clogging up the highway, preventing regular traffic from arriving at its destination.
DDoS attacks are carried out with networks of Internet-connected machines. These networks consist of computers and other devices, such as internet of things (IoT) devices which have been infected with malware, allowing them to be controlled remotely by an attacker. These infected devices are referred to as bots (or zombies), and a group of bots is called a botnet. They send traffic or requests to the victim network, inevitably shutting down the ability of the network to handle legitimate requests such as customer orders, shipping orders, and email and chat communication.
Types of DDoS Attacks
Impact on Businesses
Distributed denial of service (DDoS) attacks are now an everyday occurrence. DDoS attacks are expected to continue to increase in number and complexity as botnets and inexpensive DDoS-as-a-service platforms proliferate. One of the most significant factors in the 2020 DDoS attacks was the COVID-19 lockdown, which drove a rapid shift to online for everything from education and healthcare to consumer shopping and office work, giving hackers more targets than ever.
Adware is a type of software that automatically displays or downloads advertising content, such as banners or pop-ups, on a user’s device, often without their consent. Adware generates revenue for its developers through advertising, and it can be intrusive and negatively impact user experience.
Adware bundles itself with free software or infiltrates devices through malicious websites or email attachments. Once installed, it monitors user behavior, displays targeted ads, and may even collect personal data.
Types of Adware:
Impact on Businesses
Adware impacts businesses in several ways. Loss of productivity can occur as intrusive ads distract employees and slow down their work. Security risks are also a concern, as malicious adware may steal sensitive data or lead to more severe cyberattacks.
In addition, adware infections can damage a company’s reputation, causing customers to lose trust in its ability to protect their data. Finally, businesses may face financial costs as they must invest in cybersecurity measures and employee training to combat adware and its consequences.
Ransomware is a type of malicious software (malware) designed to encrypt files, rendering it inaccessible until a ransom is paid to the attacker for a decryption key.
Ransomware infiltrates a user’s system, often through phishing emails or infected software downloads, then encrypts the target’s files. The attacker then demands a ransom, usually cryptocurrency, for the decryption key to unlock the data.
Types of Ransomware
Impact on Businesses
The impact on businesses includes financial losses from ransom payments, downtime, critical data loss, reputational damage, and potential legal liabilities. It also forces companies to invest more in cybersecurity measures to prevent future attacks.
Fileless malware is malicious software that operates without leaving any traces on an infected computer’s hard drive or file system. Instead of relying on traditional files or executables, fileless malware resides in system memory, which makes it difficult to detect using traditional antivirus or anti-malware tools.
Fileless malware threats typically use legitimate tools and processes already present in the system, such as PowerShell, Windows Management Instrumentation (WMI), or macros in documents, to carry out its malicious activities. This makes it challenging to detect and block, as it can blend in with normal system activities.
Types of Fileless Malware Infections
Impact on Businesses
Fileless malware significantly impacts businesses, with recent examples such as the Emotet malware showcasing its destructive potential. Emotet enters systems via email attachments or links and then uses fileless techniques, such as PowerShell, to download and spread additional payloads within a network. This has resulted in widespread financial losses, data breaches, and disruptions to business operations. Fileless malware, including banking Trojans like Dridex, has also been observed using macros in documents or other legitimate tools to evade detection and steal sensitive information, leading to financial fraud and reputational damage for targeted businesses.
Spyware is a type of malicious software that is designed to infiltrate a device or system without the user’s knowledge or consent. It is typically installed on a device covertly and gathers information about the user’s online activities, including websites visited, passwords entered, and personal data such as credit card numbers and browsing habits. This information is then transmitted to a remote server where it can be used for nefarious purposes.
Spyware can be installed through various methods, including email attachments, infected USB drives, and malicious websites. It can also be bundled with legitimate software or disguised as a legitimate application. Once installed, spyware operates in the background, silently collecting data without the user’s awareness. It can also have the ability to capture screenshots, record keystrokes, intercept communications, and even activate cameras and microphones to monitor the user’s activities.
Types of Spyware
Impact on Businesses
Spyware can result in the theft of sensitive business data, such as trade secrets, intellectual property, and customer information, which can lead to financial loss, reputational damage, and legal liabilities. Spyware can also disrupt business operations by causing system slowdowns, crashes, and other technical issues. Additionally, businesses may face regulatory fines and penalties for failing to protect customer data from spyware attacks.
It is crucial for businesses to implement robust cybersecurity measures, including anti-spyware software, employee training, and regular security audits, to mitigate the risks posed by spyware.
Trojan malware, commonly known as a Trojan or a Trojan horse, is a type of malicious software that appears to be legitimate and benign but is designed to deceive users and gain unauthorized access to their systems or steal sensitive information.
Trojans typically disguise themselves as harmless files or programs, such as attachments in emails or software downloads, and trick users into executing or installing them. Once installed, Trojans can perform various malicious activities, such as stealing personal data, logging keystrokes, taking control of the victim’s computer, launching distributed denial-of-service (DDoS) attacks, or installing other malware.
Types of Trojan Malware
Impact on Businesses
Trojans, such as Emotet and TrickBot, have been used to gain unauthorized access to businesses’ systems and steal sensitive data, leading to data breaches. For example, in 2020, Emotet was responsible for several high-profile data breaches, including those of government agencies, financial institutions, and healthcare organizations, resulting in financial losses and reputational damage.
Worms malware are self-replicating malicious software that can spread through networks or the internet without requiring any human intervention. They are designed to exploit vulnerabilities in computer systems and can cause harm to the infected systems and networks.
Worms malware typically infiltrates a system by exploiting security vulnerabilities, such as unpatched software or weak passwords. Once inside, they can replicate and spread autonomously to other systems, often using various communication methods such as email, instant messaging, or network shares. Worms can also carry payloads, which can include malicious actions such as data theft, destruction of files, or creating backdoors for future attacks.
Types of Worm Malware
Impact on Businesses
Worms malware continues to pose significant threats to businesses, and there are many examples highlighting their damaging impact.
For instance, the NotPetya worm, which emerged in 2017, caused widespread disruption and financial losses for global companies such as Maersk, Merck, and FedEx. NotPetya leveraged a Windows vulnerability to propagate rapidly across networks, encrypting data and rendering systems inoperable, resulting in massive business interruptions and financial damages.
Computer viruses are a type of malicious code that can infiltrate an application and activate when the application is run. It has the potential to infiltrate a network and be used for various malicious purposes, such as stealing sensitive data, launching Distributed Denial of Service (DDoS) attacks, or executing ransomware attacks.
Virus malware works by exploiting vulnerabilities in computer systems or networks to gain entry. Once inside, it can replicate itself and spread to other devices or systems, often without the knowledge or consent of the user. It can execute various malicious activities such as deleting files, stealing passwords, intercepting communications, and conducting other harmful actions.
Types of Viruses
Impact on Businesses
The impact of virus malware on businesses can be severe, resulting in financial losses, reputational damage, legal and regulatory consequences, operational disruptions, and high remediation costs.
For example, the 2021 ransomware attack on Colonial Pipeline, a major US fuel pipeline operator, led to temporary shutdown of operations, estimated losses of millions of dollars in ransom payment, and significant operational disruptions, highlighting the detrimental effects that virus malware can have on businesses. It emphasizes the critical need for robust cybersecurity measures to protect against such threats.
A rootkit is a type of malicious software that grants unauthorized access and remote control of a victim’s computer, providing full administrative privileges to the attacker. Rootkits can be injected into various components of a system, including applications, kernels, hypervisors, or firmware. They are often distributed through methods such as phishing, malicious attachments, downloads, or compromised shared drives. Rootkits can also be utilized to hide other types of malware, such as keyloggers, making them a potent tool for cybercriminals.
Rootkits work by modifying or replacing system files, processes, or components in order to hide their presence and gain elevated privileges on a system. They can intercept system calls and manipulate system data to control system behavior and evade detection by security or antivirus software. Rootkits often operate at the kernel level, which gives them deep access to the operating system and allows them to hide their presence from regular system monitoring tools.
Types of Rootkits
Impact on Businesses
The impact of rootkits on businesses can be severe, resulting in significant financial and reputational damage.
For example, the SolarWinds supply chain attack in 2020, which involved a rootkit injected into software vulnerabilities during updates, led to data breaches and disruptions for numerous organizations, including government agencies and Fortune 500 companies. This incident resulted in financial losses and reputational damage and highlighted the need for robust cybersecurity measures to detect and mitigate rootkits and their potential impact on businesses.
Malware Attacks is an umbrella term for almost every type of cyber attack. For the most part, a cyber attack and a malware attack are synonymous terms. A malware attack is a common cyberattack where malware (normally malicious software) executes unauthorized actions on the victim’s system. The malicious software (a.k.a. virus) encompasses many specific types of attacks such as ransomware, spyware, command and control, and more.
Malware discussion typically encompasses three main aspects:
Types of Malware
The types of malware attacks are almost endless. Any type of attack that involves delivering malicious programs, code, or website links to malicious sites that automatically deliver the malicious program to the victim system.
Malware attacks include:
Impact on Businesses
Because “malware attack” is an umbrella term, any attack under it, including ransomware attacks, has a devastating impact on businesses.
SQL injection (SQLi) is a cyberattack that injects malicious SQL code into an application, allowing the attacker to view or modify a database. SQL injection attacks often target confidential information in a database like customer PII. There are a variety of SQL attacks; many will give criminals full access to a system, allowing them to change, delete or exfiltrate data.
SQL is a language used in programming that is designed for data in a relational data stream management system. SQL queries execute commands, including commands to retrieve data, update data and delete records. To execute malicious commands, an attacker can insert malicious code into strings that are passed to a SQL server to execute.
Types of SQL Injection Attacks
Impact on Businesses
SQL, an abbreviation of Structured Query Language, is a programming language that makes it easy for application developers and relevant stakeholders to access and store data within a relational database. And as we know, databases contain personal customer data, proprietary company data, and more.
MitM is a cyberattack where the attacker secretly relays and possibly alters the communications between two parties who believe that they are directly communicating with each other, as the attacker has inserted themselves between the two parties.
An attacker within the reception range of an unencrypted Wi-Fi access point could insert themselves as a man-in-the-middle. As it aims to circumvent mutual authentication, a MITM attack can succeed only when the attacker impersonates each endpoint sufficiently well to satisfy their expectations.
Types of MitM Attacks
Impact on Businesses
In a banking scenario, an attacker could see that a user is making a transfer and change the destination account number or amount being sent. Threat actors could use man-in-the-middle attacks to harvest personal information or login credentials.
A cross-site scripting attack occurs when cybercriminals inject malicious scripts into the targeted website’s content, which is then included with dynamic content delivered to a victim’s browser. The victim’s browser has no way of knowing that the malicious scripts can’t be trusted and therefore executes them.
Malicious scripts can access any cookies, session tokens, or other sensitive information retained by the browser and used within that site. Attackers can also use XSS to spread malware, rewrite the contents of websites, cause trouble on social networks.
Types of Cross-Site Scripting
There are 3 types of cross-scripting attacks, including Reflected (non-persistent) XSS, which is the most popular. To execute this type of invasion, attackers craft malicious links, phishing emails, or use various other techniques to trick victims into sending malicious requests to the server.
Impact on Businesses
Attackers can masquerade as authorized users via session cookies, allowing them to perform any action allowed by the user account. XSS can also impact a business’s reputation. An attacker can deface a corporate website by altering its content, thereby damaging the company’s image or spreading misinformation.
Password attacks are one of the most common forms of corporate and personal data breach. A password attack is simply when a hacker tries to steal your password.
Criminals can get passwords through phishing, MITM attacks, and other types of attacks, which they use to have the either type their password into a fake website that the criminal can view. Or through the phishing example above.
Types of Password Attacks
Impact on Businesses
In 2021, hackers used different password attack types, but brute force was used for more than 60% of the breaches.
It’s essential to be aware of the many different types of malware, how they work, and the damage they can cause as part of securing any online infrastructure. With advanced techniques and tactics, cybercriminals have become more sophisticated in creating new forms of malicious software that often go unnoticed. With the right knowledge and resources at your disposal, you can always stay one step ahead of cybercriminals and their malware attacks.