What Is Malware?

Malware refers to computer programs or code designed to disrupt, damage, or gain unauthorized access to computer systems. These systems may include servers, networks, and end-user mobile devices or computers. Attackers may have various goals for using malware, including:

• Financial gain

• Data theft

• Sabotage

• Disruption

• Espionage

Corporations might use malware to gain a competitive edge. In some cases, malware is the tool of state-sponsored threat actors. In other cases, hacktivists use malware to promote an ideology or make a statement.

In this article, we’ll explore the different types of malware and how they infect devices. We’ll also cover attack prevention and how to combat malware with cutting-edge cybersecurity tools.

Types of malware

Malware is classified based on its behavior when infecting a system. In this section, we’ll cover the most common types of malware and the threat that each type poses to computers or networks.

Ransomware

Ransomware encrypts data and demands that a victim make a ransom payment to regain access. An increasingly common tactic in recent years is double extortion, where attackers steal data before encrypting it.

Fileless malware

As the name implies, fileless malware is a stealthy threat that does not rely on a file to carry out malicious activity and infect computer systems. Instead, fileless malware operates in the computer’s memory, using legitimate system features and disappearing after a reboot. As a result, this type of malware is difficult to detect and remove.

Spyware

When spyware infects a computer, it gathers information without consent. It harvests personal information before sending it to attackers.

Adware

Adware delivers unwanted advertisements, such as through pop-ups or browser hijacking. Often bundled with free software, adware can serve as a vector for more dangerous malware.

Trojan

A trojan appears as a legitimate software application. If installed, attackers gain backdoor access to computers that allows them to steal personal information, monitor activities, and destroy files.

Worms

A worm self-replicates and spreads across computer networks without user intervention. Worms exploit vulnerabilities in the operating system to penetrate a network, and then they spread and cause disruptions.

Rootkits

Rootkits offer attackers remote access and control of computers, giving them deep system access at the kernel level. Rootkits are commonly used to hide other malware.

Mobile malware

Mobile malware attacks mobile devices, especially those running on Android. They can infect phones if an end user downloads and installs applications from unofficial sources.

Exploits

An exploit is a piece of programming code that targets a vulnerability in a computer software application or operating system. Attackers use exploits to install malware on computer systems.

Botnets

Botnets are malware-infected computer networks. Whoever controls this network can use it to launch distributed denial-of-service (DDoS) attacks, spamming attacks, and cryptojacking attacks. For example, the Mirai malware exploits default internet of things (IoT) credentials to add devices to a botnet.

Malspam

Malspam refers to spam email messages that deliver malware to computers using infected email attachments or malicious links. The malware is installed after the user clicks a link in the email or opens an attachment.

Cryptojacking

Attackers use cryptojacking malware to hijack computer resources and mine cryptocurrency without consent. 

Malware infection across devices

Any internet-connected or networked device without adequate protection is vulnerable to malware infection. In this section, we’ll explore how these devices can become infected with malware along with signs of an infection.

PCs and laptops

The widespread use of PCs and laptops running Windows and Linux makes them prime targets of malware creators. Common indicators of infection include slow performance and unexplained rebooting. In the case of ransomware, unusual network activity may occur as threat actors exfiltrate data.

Macs

Once considered immune to malware, Macs are susceptible to infection like other devices. Atomic Stealer and Cthulhu Stealer are examples of Mac malware that steal web browser cookies and cryptocurrency wallets before sending them to attackers. Possible signs of infection include unusual login locations or unauthorized access attempts into the web accounts on a user’s Mac.

Android devices

Mobile malware can infect Android devices if the user is a victim of SMS phishing (smishing). For example, in 2021, TianySpy malware lured users through smishing. Unfamiliar applications on devices can be a sign of malware.

iOS devices

Exploited vulnerabilities and jailbreaking are two ways iOS devices can become infected with malware. For example, in 2023, researchers discovered that iOS devices could be infected with malware after receiving a message via iMessage. Without user interaction, the message triggered a vulnerability that executed code.

IoT devices

Default settings or weak security protocols (such as adopting default passwords) can leave IoT devices vulnerable to malware. As a result, malware can infect smart home devices, cameras, or other connected appliances, potentially allowing attackers to control or monitor them.

Preventing malware attacks

Below are several practices that can help organizations prevent or recover from malware attacks. 

Next-gen antivirus (NGAV)

NGAV solutions combine machine learning and behavior analysis to identify known and unknown threats on a system. Over time, NGAV continuously learns from observed patterns and suspicious behavior.

Regular system updates and patching

Applying regular updates and patches can offer up-to-date protection against malware. Hardware, software, and operating system vendors release security updates to help safeguard systems from vulnerability-targeting malware. However, this protection depends on users to apply patches and keep their systems updated.

Zero Trust architecture

To mitigate malware attacks, limit access to systems and networks using a Zero Trust architecture. This type of approach operates on strict identity verification. Even after initial verification, users and devices are required to continuously authenticate whenever permissions are needed to perform tasks or access systems.

Email and web security awareness

End-user education is important for stopping malware attacks. Organizations should train their teams and employees about email and web security. Explain terms like phishing, smishing, social engineering, and more. Additionally, organizations should emphasize the importance of scrutinizing applications, ensuring they are from official, vetted sources before downloading and installing them.

Backing up critical data

Regularly backing up critical data helps with malware attack response, especially when responding to ransomware. For simplicity, some organizations follow the 3-2-1 rule of backups:

• Three copies

• Two different types of media

• One in an offsite location

This general rule ensures that files can be restored during a ransomware attack.

Multi-factor authentication (MFA)

Threat actors can use stolen credentials to breach networks. Enable MFA for an extra layer of security to prevent unauthorized access, even if credentials are compromised.

Endpoint detection and response (EDR)

An EDR system enables organizations to monitor and respond to potential threats in real time. They can identify unusual activities indicative of malware by utilizing advanced behavioral analysis, AI, and machine learning.

Combat malware with cutting-edge cybersecurity tools

The evolving nature of malware requires up-to-date strategies and tools. Advanced malware protection, such as EDR and NGAV, is essential. For NGAV, consider CrowdStrike® Falcon Prevent®. For EDR, consider CrowdStrike Falcon® Insight XDR.

The CrowdStrike Falcon® platform uses AI, machine learning, and behavior-based detection to stay ahead of advanced malware. The platform neutralizes malware across all devices and environments, providing real-time protection and advanced threat detection. 

Experience the Falcon platform with a free trial today.