What is Malware?

Malware is a contraction of malicious software. The umbrella term refers to viruses, worms, trojans, and other malicious computer programs hackers use to gain unauthorized access to systems and data.

Malware encompasses any program that causes damage to a computer, server, or network, regardless of the technology used to create malicious software.

Key Takeaways

  • Malware is any computer program intended to exploit systems, gain unauthorized access, and steal information.
  • A malware falls under different categories, based on the way they spread worm, virus, or trojan
  • You can also categorize malware based on their activities, for example, spyware, adware, rootkit, and ransomware
  • Hackers can also install malware manually by gaining physical access to a target’s computer
  • You can use a signature-based tool like SIEM to detect malware

Types of Malware?

Malware falls into different categories, based on the way the malicious software spreads or operate.   

Common malware types, based on the way the malicious program spreads include:

  • Worms: a worm is a standalone piece of malicious program that can self-reproduce and move from one target to another
  • Viruses: A virus is a harmful software that inserts itself within the code of a genuine standalone program. A virus forces the standalone program to take malicious action
  • Trojans: A trojan is a piece of code that masquerades as something the victim wants and tricks them into clicking to cause damage. Unlike worms, a trojan cannot reproduce itself.


The second malware categorization is based on the way the program operates. Under this type, we have:

  • Spyware: this malware secretly collects data from unsuspecting users. A spyware spies on victim’s behavior as they interact with their devices and share information. In most cases, spyware sends the logs to a third-party for further action.
  • Rootkit: a rootkit is a program or a collection of software tools that grant hackers remote access and control over victims’ systems and computers. As its name suggests, a rootkit gains root access with administrator-level control over a target system.
  • Adware: This malicious program forces user browsers to redirect to unsolicited web advertisements with download links.
  • Ransomware: this malware encrypts your computer files and demands a payment in exchange for the decryption key. Hackers demand ransom in cryptocurrency to avoid identification and traceability. Bitcoins offer anonymity since converting money to the currency, sending and receiving it, does not require legal names or addresses.
  • Cryptojacking: cryptojacking malware infects devices and uses CPU resources to mine Bitcoin without your knowledge. The harmful program uses computing power and memory to mine or steal cryptocurrencies.

Other Ways Cybercriminals Distribute Malware

  • Phishing Emails: Hackers use phishing emails to spread malware. In this distribution method, attackers craft an email that easily tricks a victim into opening an attachment or a malicious website link. Once the user opens the harmful PDF, ZIP, or word doc, the malware encrypts their entire data or spreads to other computers in the network.
  • Remote Desktop Protocols: A hacker can also use the remote desktop protocol to gain access to machines with open ports
  • Compromised Websites: Bad actors can use compromised websites to distribute ransomware via vulnerable software downloads.
  • Manual Installation: Hackers can install malware on a target device manually by gaining physical access to a computer. Additionally, attackers can use privilege escalation to gain remote administrator access.

Malware in Mobile Devices

Does malware attack mobile phones? Yes.

Malicious programs can target mobile devices, giving cybercriminals access to the device’s components, such as files, camera, GPS, microphone, and contacts. Phones get infected when a user downloads an unofficial application from Google Playstore or a vendor’s website.

Attackers also spread malware to mobile phones through a Wi-Fi or Bluetooth connection.

How to Detect Malware

You can deploy various tools to scan and see what is going on in your network. You can install a security information and event management (SIEM) system to collect, analyze, and give insights from computer and application logs.

Increases in data usage, calls, texts and emails being sent to your contacts without your knowledge, and a quickly dissipating battery can help you detect if your mobile device has malware.

How to Prevent Malware

You can employ the following measures to prevent malware:

  • Make sure you know how to spot spam and phishing emails that hackers use to spread malware
  • Install an antivirus, antispyware, or antimalware products to detect and neutralize viruses, worms, and trojans
  • Keep your systems patched and updated
  • Keep an inventory of all your IT assets so that you know what you need to assess and protect
  • Backup your systems and files to ensure timely incident response and business continuity in case of a ransomware attack