Malware types and how to prevent them

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.

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

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. 

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

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

To prevent Trojan malware:

1. Refrain from downloading files from unrecognized sources don’t recognize.
2. Don’t open attachments or links in unfamiliar emails.
3. Perform updates and download the latest security patches for devices and all programs.

Bots represent malicious malware types -- 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 a device or website for valuable information.

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

To protect user-facing webpages from harm:

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

Ransomware is a form of malware that takes hostile control of files or devices, blocking access until a ransom is paid. 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 port settings regularly and use virus scanners familiar with common ransomware programs.
3. Maintain backup files in case original documents become locked. Backup files give leverage in a ransomware situation and may provide enough time for professional IT specialists to assist with recovery.

Among malware types, spyware is far more discreet than many other forms of malware. It transmits personal information directly from a 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 a device. Spyware resembles other forms of malware in how it affects a device. Users might notice slower application load times, slower internet processing times and unexpected program crashes. In addition, spyware can cause unexplainable increases in a 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 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.