Types of malware and how to prevent it

Understanding malware

Malware, or malicious software, is an umbrella IT term that refers to different types of intrusive computer programs that steal sensitive information or damage computer systems. Hackers commonly use malware to force their way into a device or network and compromise normal device functionality.

As cybersecurity technology evolves, hackers are growing more aggressive in distributing hostile malware and more clever at devising social engineering schemes to disguise malware attacks as benign messages. Today, more than 1 billion malware programs currently circulate in computer systems across the web. Though annual malware attacks are down year over year, the attacks themselves are costly.  For example, ransomware attacks cost an average of $4.54 million in 2021.

Here are the most common types of malware in circulation, along with information on how it can affect your device — and how to prevent it.

Worms

Computer worms infect devices and quickly self-replicate, compromising performance while identifying and infecting connected devices. Worms typically access a device’s network and move laterally across all other devices in that system. Once a worm exploits a security issue on a single device (the “host”), it can infect other devices — even if those secondary devices are fully protected. The highest-functioning worms can replicate across many devices, servers and networks without human interaction.

Many firewalls and antivirus programs offer strong worm protection and can help identify suspicious items in emails or other forms of messaging. Worm prevention becomes more challenging after worms infect a network. Even if you eliminate many of the worms infecting secondary devices, the worms can continue to replicate until the host device is cleansed.

The bad news? Remnants of worm activity can affect productivity across your networks long after the worm is removed.

Because of the potential for damage from a computer worm, many organizations turn to professional cybersecurity assistance. If you’re interested in helping companies defend against computer worms, consider obtaining a bachelor’s degree in cybersecurity. This degree program teaches aspiring cybersecurity professionals skills in network security and vulnerability.

Trojans

Trojans, or Trojan horses, are virtually any malware that misleads users. Trojan code maliciously takes control of your device after disguising itself as a legitimate computer program.

You’ll notice device performance issues soon after a Trojan arrives. If your computer or phone displays interruptive pop-ups or spam messages, it might be infected.

To prevent Trojan malware:

1. Refrain from downloading files from a source you don’t recognize.
2. Don’t open attachments or links in unfamiliar emails.
3. Perform updates and download the latest security patches for your device and all programs.

Bots

Bots represent malicious programs that hackers use to control devices. Malware bots can resemble legitimate bots that search engines use to perform repetitive tasks. In the same way Googlebot indexes webpages, a malicious bot repeatedly crawls your device or website for valuable information.

Preventing bots means protecting your devices and website from malicious crawls. To protect your device, consider installing a strong antivirus program that limits a bot’s entry points and automatically crawls your running processes for unauthorized activity.

To protect user-facing webpages from harm:

1. Block outdated browsers from accessing your website.
2. Take time to evaluate traffic sources through data-tracking tools to identify where website traffic enters and exits your website.
3. Pay close attention to failed website login attempts and investigate unexpected spikes or drops in page visits.

Because bots can affect your organization’s devices and web elements, many companies turn to professional IT support for help. Students looking to join the IT workforce should consider pursuing a bachelor’s degree in information technology, where they will reinforce skills in information systems, cybersecurity and systems analysis.

Ransomware

Ransomware is a form of malware that takes hostile control of your files or device, blocking access until you pay a ransom. Hackers often threaten to erase a device’s data unless ransom demands are met. In other cases, hackers threaten to make the device’s information public.

Ransomware works by encrypting a device, or specific files within a device, and preventing user access. Soon after, hackers make the ransom demand.

Preventing ransomware starts with healthy device-use habits:

1. Don’t download files and applications from unknown sources.
2. Review your port settings regularly and use virus scanners familiar with common ransomware programs.
3. Maintain backup files in case your original documents become locked. Backup files give you leverage in a ransomware situation and may provide enough time for professional IT specialists to assist you.

Spyware

Spyware is far more discreet than many other forms of malware. It transmits personal information directly from your hard drive to other locations.

Unlike bots or worms, spyware is typically distributed to specific devices for specific purposes. Hackers might be searching for incriminating information they think is on a user’s hard drive, or mining for a particular set of login credentials.

Spyware is challenging to identify since its primary goal is to hide on your device. Spyware resembles other forms of malware in how it affects your device. Users might notice slower application load times, slower internet processing times and unexpected program crashes. In addition, spyware can cause unexplainable increases in your device’s data use.

It’s much easier to prevent spyware than to eradicate spyware once it begins to affect your device. Preventing spyware means practicing safe internet and email habits, monitoring device data-usage trends and the permissions you allow for each application.

Rootkits

Rootkits are designed to grant hackers undetectable access to a device. Unlike worms and viruses, which depend on sheer volume to overwhelm a device, rootkits are targeted attacks by hackers attempting to avoid detection.