/ Glossary / What is Malware and How to Prevent Malware Threats?

What is malware?

Malware, short for malicious software, is an umbrella term for many types of computer programs created to disrupt or exploit a network, device, or service. This includes a wide array of cyberattacks like computer viruses, ransomware, and spyware. Malware is designed to gain unauthorized access to a computer or network, disrupt business operations, or damage data and systems. Attackers use malware to distribute malicious code, or “payload,” via a link or file over email.

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What are the 3 types of malware?

Malware can be categorized based on how the malicious software spreads. According to this categorization, there are three basic malware categories:

  1. Computer worm: This type of malware starts by infecting one machine and then spreading computer by computer through the network. Worms can infect entire networks very quickly.
  2. Virus: This is the most common type of malware. A virus works a lot like the biological version, self-replicating and spreading, causing damage to computer systems' core functionality and corrupting files. Usually, viruses attach the code through a file executed via an unsuspecting user. Other times, the virus is automatically executed when the user clicks on a link.
  3. Trojan: As the name suggests, this type of malware hides its true intentions by passing as legitimate software. Once inside the network, the Trojan horse creates a backdoor that gives attackers access to the system, where it can move laterally.

What does malware do?

Malware attacks can lead to everything from spamming users with ads to stealing sensitive data. There are different actions malware can perform after infecting a device or network.

Spyware/keylogger

This malware is designed to follow what the user is doing by spying and collecting data on the activity of the user’s computer, sending this information to a third party (e.g., keystrokes). This malware runs in the background undetected, collecting credit card details, authorization credentials, and other sensitive data. When the spyware specifically records the keystrokes, it is called a keylogger.

Adware

This malware directs the victims’ web browser to fake advertisements, often in popup windows, which then are used to download malicious software. Adware usually attaches itself to “free download” programs like games or browser extensions.

Ransomware

In this attack, cybercriminals lock out users until the victim pays a ransom. Sometimes attackers encrypt your files, demanding payment for sending the decryption key. Ransomware attacks are often executed as part of phishing scams and social engineering, and target large organizations with heavy costs.

Rootkit

In this type of attack, instead of using one software, attackers use a group of software tools to gain remote access and control a network or system. These tools are installed at the root (administrator level).

Malvertising

This method infects legitimate ads or ad networks to deliver malware to users’ computers. Passing malware as a legitimate ad on a website, an attacker lures the user into clicking on it. The code then redirects them to a malicious website or directly installs malware on their computer.

Crypto-jacking

Here, attackers force your computer to supply them with cryptocurrency without you knowing. They install a crypto-mining malware that infects the computer, using the CPU to mine bitcoin for your attacker.

Scareware

This is a trick made to look like ransomware. In it, a criminal sends a warning or alarming message to the user’s browser. This message tricks the user into thinking their computer has been infected and they need to download a fake antivirus or application to protect it. In other versions of scareware, the criminal uses redirect links to show the user their files are encrypted or they’re locked out of their system, then demands a ransom to recover access.

How can malware attacks be prevented?

Preventing malware requires constant vigilance by users—and installing the right protection tools. User vigilance is key to ensure that emotion, such as fear, does not lead to risk. Attackers can trick an employee into installing a fake antivirus by sending a scary message telling them, “Your computer has been infected.” Another can be lured into downloading a “useful browser extension.” Protecting against malware involves maintaining good security hygiene and best practices, along with protection tools. There are several tried and tested tips for securing networks and systems:

Update applications and operating systems regularly

Malicious actors are constantly updating their attack methods. Thus, systems need to be up-to-date to withstand new attack vectors. To strengthen endpoints so they can reject malicious intruders, it’s important to review and patch them promptly and often. That way, the business can ensure there are no hidden vulnerabilities that attackers can exploit in operating systems and applications.

Use good security practices

The first line of defense is users’ awareness. Staff and end users should be aware of risk areas like password security, how to use multi-factor authentication, and identifying the signs of a potential attack. Another area of security is secure email practices. This is one of the most effective ways to protect against malware since it commonly spreads via email. For instance, users should always avoid opening suspicious emails or clicking suspicious email attachments. Attachments should be scanned before being opened, as this can prevent a malware infection from spreading. In case of doubt, users can forward the email or file to IT security before opening it.

Limit the number of applications on the computer

Attractive free apps are one of the favorite ways for attackers to install malware in a system or computer. Most devices have more apps installed than are actually used. Reducing the number of applications and ensuring users install only what is needed is a way to protect against malware that may be lurking in idle apps. Unused software is seldom updated or patched, and sometimes people may even forget that an application is installed. This creates an ideal environment for an attacker to exploit vulnerabilities by using an idle app to enter the system. A secure workspace that controls all applications under a unified environment helps to keep application security tight.

Use malware protection tools like antivirus software

Anti-malware software monitors systems to detect malicious activity before it becomes a problem. Security tools like antivirus and firewalls can identify malware and stop it in its tracks by detecting known signatures. Endpoint security tools provide an additional layer of protection by providing anti-spyware, application control, and preventing other types of intrusion.

Create backups

Backups are a basic measure for protecting sensitive information from malware attacks and other cyberattacks. Users should not only regularly update their backups, but also store the records in multiple locations to ensure redundancy and eliminate the risk of having to pay a ransom if a hard drive is compromised. This protects files from attacks and other disasters. Cloud backups can also be a good option for storing sensitive data.

How can malware be detected?

Sometimes, a slow device can be an indication of an infected computer—particularly if the system is acting differently and various applications don’t interact as smoothly as before. But how can the user detect if there’s a malware infestation? Even if malware protection is installed, new attack vectors are being created all the time—ones that can slip past existing defenses.

There are several signs that could indicate a computer has been infected by malware:

  • Slow computer performance: This is often the telltale sign of malware infection. If a system is suddenly slow, it may mean that you need to dig deeper.
  • Network traffic signs: Security admins can detect malware by checking network traffic. They might analyze network traffic to suspicious domains, or investigate unusual activity like too many requests for dynamic DNS. These services are used by malicious actors because they provide the possibility of adding domains quickly.
  • Automatic browser redirects to unintended sites: While many site redirects are legitimate, getting redirected to an unfamiliar site can be a sign of malware. The redirection can be concealed as a fake site looking just like the real site the user is trying to reach. In this case, the problem can be detected by looking at the unfamiliar URL in the address bar. In addition, new browser settings, extensions and toolbars may also be a sign of malware.
  • Problems starting or restarting the device: When someone is suddenly unable to start a computer or access a workspace, it can be a sign of malware.
  • Frequent pop-up ads that seem to come from nowhere: This is a method frequently used by adware programs. Sometimes the ads appear legitimate, while others contain links to malicious websites.

Corporate network security tools, such as intrusion detection or threat detection systems, pick up signs of malware infection that may otherwise be missed.

How can you remove malware?

The process for removing malware depends on the type of malware that’s been installed, and the security software and procedures vary. For this reason, it’s imperative for organizations to develop an incident response plan that allows the business to respond quickly to a malware attack.

Citrix solutions for malware prevention

Citrix security solutions, including Citrix Secure Private Access and Citrix Secure Internet Access, protect data across mobile devices, personal computers, desktops, laptops, tablets, and mobiles from wherever the user connects, at the application level. This unified secure workspace approach enables organizations to isolate corporate data, applications, and networks by securing access and browser services.