Malware and Viruses – what are they?

Updated on October 21, 2022, by Xcitium

What Is Computer Malware and Viruses?

Computer malware is any software designed to harm, disrupt, steal data from, or gain unauthorized access to a device or network. A computer virus is a specific type of malware that attaches itself to legitimate files or programs and spreads when those files are executed. While all viruses are malware, not all malware is a virus.

Many are confused with the terms malware and viruses. Both are types of software that are harmful to the computer. But knowing the difference between the two gives us a better understanding of what is computer malware and viruses.

What is the difference between Malware and Viruses

To put it simply, a virus is a type of malware that is capable of self-replicating once it enters the computer. Malware is a broader term where Virus, Trojan, Adware, Spyware, Ransomware, and other types of malicious software fall under.

Each malware operates differently. It is created to perform a specific function. In general, all types of malware are harmful to the computer.

To understand malware better, let’s discuss the different types of malware.

Malware vs Virus: What’s the Difference?

Malware	Virus
Broad category of malicious software	Specific type of malware
Includes ransomware, spyware, Trojans, worms, and viruses	Spreads by attaching to files or programs
May not require user action to spread	Usually requires user interaction
Can steal data, monitor activity, or damage systems	Primarily replicates and spreads
Multiple attack methods	Focused on infection and replication

A virus is one type of malware, but malware includes many other cyber threats beyond viruses.

Common Types of Computer Malware

Virus

A virus is a type malware that can self-replicate through an executable file. Once the user runs the file it attaches itself to, the virus starts spreading throughout the computer. Then it can overwrite the data which destroys important files and legitimate applications.

A virus is spread through a spam or a phishing email. Note that a virus cannot spread until the user runs the infected software.

Worm

A worm is another self-replicating malware. The difference between worm and virus is that worm spreads independently on the computer without the help of an executable file.

Once it enters the computer, it spreads fast, then travels within the network, and infects the other host computers. Once worm overloads the network, it may result in network interruption.

Ransomware

A ransomware is expert at encrypting files. Once installed, it loads in the computer memory and it deletes itself. That doesn’t mean that it no longer exists, it’s very much active. It does that to remain undetected so that it can access the hard drive files covertly.

What’s more alarming is that Ransomware targets specific files such as PDF, Word, or videos that are valuable to the computer so that paying the ransom is guaranteed. Note that once the files have been encrypted, they cannot be restored without the decryption key that the hacker holds.

Trojan Horse

A trojan deceives its victim into installing it by pretending to be a genuine file. Often, the user has no idea that it is a malicious file because it looks like a normal software. It can pretend to be a fake installer or update.

Once installed, Trojan is known for installing more malware. Then the other types of malware give the hacker control on the computer without being exposed.

Spyware

Spyware lies between the web browser and web server that gives it access to all kinds of information that user searches on the Internet. Therefore it can be used to record Internet calls and messages.

What’s worse is can also record account details such as username and password. The hacker then can use the information to empty the user’s bank account.

BOTS

BOTS are virtual robots that target computers with a poor antivirus. Once the computer is infected with BOTS, it becomes a part of the collection of zombie computers.

Once installed, BOTS wait for a specific command coming from the central server that a hacker controls. BOTS can transmit bank account information to the hacker’s end, which can be used to transfer money.

Now that we have a clearer idea of what is computer malware and viruses, how do we know if we have malware in the computer?

What Do Malware and Viruses Do to a Computer?

Malware and viruses can:

Steal passwords and personal information
Slow system performance
Delete or corrupt files
Monitor user activity
Display unwanted advertisements
Encrypt data and demand ransom
Provide remote access to attackers
Disrupt business operations

The impact depends on the type of malware and the severity of the infection.

Signs Your Computer May Be Infected

Common symptoms include:

Slow computer performance
Frequent crashes or freezing
Unexpected pop-up advertisements
Browser redirects
Disabled antivirus software
Missing files
Unusual network activity
Unauthorized account access
Unknown programs running

If several symptoms occur simultaneously, perform a malware scan immediately.

Malware and Virus Prevention Checklist

✓ Install reputable endpoint protection software

✓ Enable real-time threat detection

✓ Keep software and operating systems updated

✓ Avoid suspicious email attachments

✓ Download software only from trusted sources

✓ Use strong, unique passwords

✓ Enable multi-factor authentication (MFA)

✓ Back up important files regularly

✓ Conduct regular security scans

✓ Train employees on phishing awareness

How Malware and Viruses Affect Businesses

Cyber threats can lead to:

Data breaches
Financial losses
Productivity disruptions
Compliance violations
Reputation damage
Customer trust issues
Operational downtime

Organizations require layered cybersecurity strategies to reduce these risks and maintain business continuity.

What is computer Malware and Viruses sign in computer

Unusual Error

Windows only displays an unusual error when there’s a bug in the computer or critical data is infected. If an unusual error keeps reappearing on the computer, it could be a sign of malware infection.

Run a malware scan immediately before malware does further damage to the computer. Malware scans will detect threats hiding in the computer.

Low Disk Space

We have mentioned that malware consumes the computer memory that results in low disk space. If the computer is running out of space, Windows usually displays a balloon notification at the bottom of the screen.

It’s better to check what consumes the computer’s memory. If there’s a suspicious file, uninstall it; it could be malware.

Slow Computer

Reduced computer speed is a sure sign of malware. Because malware consumes space and destroys computer data, it definitely results in a slow computer. The computer programs need enough space to run properly. In addition, once malware has destroyed the computer data, the applications start crashing.

Xcitium Do you think that your computer is infected with malware? There are ways to remove them. Click here to learn about malware removal and prevention techniques.

Frequently Asked Questions

What is the difference between malware and a virus?

Malware is a broad term that describes all malicious software, while a virus is a specific type of malware that spreads by infecting files or programs.

Are all viruses malware?

Yes. Every virus is considered malware because it is designed to perform malicious actions on a system.

Can malware steal personal information?

Yes. Many types of malware, including spyware, Trojans, and keyloggers, are designed to collect passwords, financial data, and sensitive information.

How do malware and viruses infect computers?

They commonly spread through phishing emails, malicious downloads, compromised websites, infected USB drives, and software vulnerabilities.

Can antivirus software remove malware?

Modern antivirus and endpoint security solutions can detect and remove many forms of malware, especially when real-time protection is enabled.