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What is Malware? Understanding Attack Types

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Malware Definition

What is malware? Malware refers to the various types of malicious software, such as viruses, spyware, and ransomware. Cyber criminals use these tools to gain access to a network and its devices to steal data or damage systems.

There are some telltale signs you can learn that typically indicate you have been the victim of a malware attack, including:

  1. A slow computer. Malware often affects the speed of your device while you are using the internet or applications.
  2. A computer that frequently crashes or freezes during normal use.
  3. A ton of pop-up ads. These often indicate that adware, a type of malware, has gotten into your system. If you see these, it is important to not click on them because they could launch code that causes further damage.
  4. A loss of disk space. If you feel your available disk space has suddenly diminished, it could be because malware is on your hard drive.
  5. A swell in internet activity on your network. Some automatically access the internet, causing an unusual increase in internet activity that does not correlate with user behavior.
  6. When your system is working harder than it normally would. This could be due to malware taking up valuable resources.
  7. Your browser is showing new toolbars, extensions, or a different homepage.

What is Malware? Understanding the Different Types of Malware

Although many consumers presume malware threats only attacks desktops and laptops, it can actually infect several types of endpoints. These include phones, mobile devices, and other products.

Here are the different types of mobile malware that may impact your online network or attached devices.


Viruses are perhaps one of the most well-known malware types. They link their malicious code with clean code and wait for a user to execute it. They spread quickly through a variety of systems, affecting how they work. They also corrupt website content files and prevent users from accessing their computers. They are often hidden inside an executable file.


Worms move their way through a network by forming connections with one machine after another. In this manner, they move between connected computers and can quickly infect the whole network if not stopped.

Trojan Viruses

Trojans are named after the Trojan horse from Greek mythology. Similar to Greek soldiers hiding inside an apparently innocent structure, Trojans appear to be legitimate software. Because they seem innocent, they are accepted into the user’s computer. There, they create backdoors, allowing other advanced malicious software to gain access to the device.


Spyware keeps track of what a user does on their computer. Spyware hides, like a spy, in the background of a user’s computer, collecting information without the user’s knowledge. This may include sensitive data like credit card details and passwords.


Ransomware can lock down a computer or an entire network and prevent users from accessing it until they pay a ransom to the attacker. After the ransom is paid, the attacker provides password information on how the user can take back their system.


Adware results in tons of ads and features appearing on your screen, often while you are using a web browser. Adware may gain access by appearing to be an innocent ad or by attaching itself to another app, gaining access to your system when you install the apparently benevolent program.


Rootkit gives the attacker the same privileges an administrator would have. It stays hidden, allowing the attacker to access the computer and make the kinds of changes normally only accessible to someone with administrator credentials.


A keylogger has the ability to record the keystrokes a user makes on the keyboard. It can then store this information and send it to an attacker. The attacker can then use the data to figure out passwords, usernames, and payment details.


Cryptojacking involves using a computer or other devices to mine for cryptocurrencies. An attacker uses the computing power of the target’s device to solve the complicated equations needed to generate digital currencies.

Rogue Software

Rogue software pretends to offer targets help with getting rid of viruses and other kinds of malware. It then coerces them into, inadvertently, installing—and paying for—malware.


Scareware uses social engineering to frighten or shock a user into thinking their system is vulnerable to an attack or potential hacking. However, no danger has actually been detected— it is a scam. The attacker succeeds when the user purchases unwanted—and dangerous—software in an attempt to remove or eliminate the “threat.”


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What is Malware in the Business World?

Although anyone with a device is susceptible, businesses are often the preferred targets. This is due to a few different reasons.

When executing a malware infiltration on a business, there exists the potential for a larger-scale attack. For an attacker, they want to get as much “bang for their buck” as possible, and the more devices they can access, the better. Most businesses have multiple devices connected to a central network. They may also share a central server, such as one that houses data or email services. If an attacker is able to get malware past an organization's defenses, it can affect all devices connected to the network.

Another reason why businesses are often the target of choice for malware-armed criminals is the potential for profits. This is particularly true when it comes to ransomware. Attackers know that if a company’s operations are interrupted, each minute that goes by costs them money. In the case of a ransomware attack, the business may be tempted to shell out the cash the attacker is asking for, simply because that expense is less than what they are losing as the attack progresses.

In a larger company, these risks are multiplied because the attack surface is expanded, as are the opportunities. As the size of an organization goes up, so does the number of devices, users, servers, and other entry points for malware. The plethora of potential vulnerabilities often makes larger enterprises more attractive targets than smaller ones.

How to Guard Against Malicious Software Attacks

It is important to be proactive when trying to avoid attacks. This involves a combination of prevention, preemptive mitigation, and education.


How to guard against malicious software attacks

Avoid Malware

Most malware is relatively easy to spot if you know the signs. The most common places to encounter it are within emails and pop-ups that appear on your device either while using the internet or in the course of normal operation. 

Phishing schemes that seek to get users to disclose sensitive data could also use malware so that even if you do not provide the information the phisher needs, you still end up clicking something that gives them access to your system. Therefore, it is a good idea to never click on anything that appears randomly on your screen or anything in an email—attachment or otherwise—that seems suspicious.

Back Up Data

Backing up data is a form of preemptive mitigation that will be invaluable if a malware attack is successful. All endpoints and servers should have backups that are shielded from malware. If an attack is successful, you can use the backup to restore your system after wiping it.

Educate Employees

All employees should have a working understanding of what malware is, how it penetrates a system, its effects, and how to best avoid it. This may include arming them with preventative knowledge such as the value of multi-factor authentication (MFA) and developing strong passwords. Employees should also know to look for red flags in an email or pop-up, as well as who to notify and what to do—or not do—if they suspect their endpoint has been exposed.

Check for Vulnerabilities

Have a full security system that can help you find the places where malware might enter your network. A proactive security system can closely monitor all endpoints, including mobile devices, as well as a variety of servers, both on-premises and in the cloud.

Isolate Viruses with Sandboxing

Sandboxing isolates viruses by confining them to a protected environment. Inside a sandboxed area, the IT team can observe how the malware behaves and how it reacts to security measures taken to neutralize it. All the while, other devices and sections of the network are protected from infection. You can isolate malicious software with FortiSandbox.

Use Firewall Protection

Next-generation firewalls (NGFWs) protect an organization from malware by filtering network traffic. This includes traffic entering and exiting the network. Two-way protection is important because malware within your system can be leveraged to affect users, devices, and networks that connect to yours. NGFWs incorporate packet filtering, network monitoring, Internet Protocol (IP) mapping, IP security (IPsec), and secure sockets layer virtual private network (SSL VPN) support. It also uses deeper inspection measures to protect a company from intrusion or from having applications hijacked.

The Fortinet NGFW solution is constantly updated to stay ahead of the latest threats in the cyber universe. Each update provides the NGFW with the data it needs to filter the latest and most dangerous threats. Protect against malware and more with FortiGate

Detect Malware with Antivirus

The Fortinet antivirus services leverage the power of the FortiGuard Labs Global Threat Intelligence system. In the span of a minute, FortiGuard eliminates, on average, 95,000 malware programs. FortiGuard does this by incorporating knowledge of the different types of malware within the global threat landscape. Countermeasures are engineered to neutralize each type of threat, and then they are automatically enacted by FortiGuard, thereby protecting the networks under the FortiGuard umbrella.

The FortiGuard antivirus protection system comes with FortiGate, FortiSandbox, FortiMail, FortiWeb, FortiCache, and FortiClient. Stop malware attacks with Fortinet antivirus services.