Malware Phishing Trojans Virus Worms

How Are Computer Virus, Trojans And Worms Different From Each Other?

Malware spread is rising rapidly and our computer security is at stake. Different types of malware are used by hackers to hack into our system and commit cyber crimes. Nowadays we all are getting news of identity frauds, phishing scams and what not. Many people don’t even know what has attacked their system so they can’t deal with it. Knowing about different types of malware is a necessary step, considering the present scenario.


How many of you know the difference between a computer virus and trojan? Or between a trojan and worm? Or even between the three of them? If you want to know about it then you can find it in this article. In this article we will read about the difference between virus, worms and trojans and how such infections spread.

Starting with the basic definitions, we can say that:

  • Virus is a type of computer program or malicious software that connects itself to computer program or some other software and harms it.
  • Trojan is a type of malware that captures important information about a computer network or system.
  • Worms are the type of malware that replicates itself which eventually slows down the computer system.

Replication :

  • Virus replicates itself.
  • Trojans horse doesn’t replicate itself.
  • While worms have the ability to replicate itself.

Control :

  • Viruses are not controlled by remote.
  • Trojans can be controlled by remote.
  • Just like Trojans, Worms can also be controlled by remotes.

Spread :

  • Viruses spread at a moderate rate.
  • Worms have a faster spreading rate when compared to virus and Trojans.
  • Spreading rate of Trojan horse is slower than worms as well as virus.

Objective :

  • The main objective or aim of virus is to modify any information.
  • Trojan horse works with the objective of stealing information.
  • Worms as the name suggests has the objective of eating the system resources.

Execution :

  • Executable files are used to execute viruses.
  • To execute Trojan horses a programs that interprets as utility software is used.
  • The vulnerabilities of weaknesses of a system execute worms.

Spread of virus, worms and trojan horses:

How does these infections spread? By knowing this you can prevent your system from getting infected and your privacy from being breached.

Worms :

  • Most of the infections that attack your system are because of internet. There are links infected to website hidden in the HTML of website and because of that whenever that page loads infection is triggered.
  • Email attachments often carry worms and whenever someone opens that link the infection starts to spread.
  • Downloads and FTP servers can also contribute in spreading worms to your system. It starts by infecting individual FTP files or downloaded files. But if it goes undetected the harms caused by it can spread to the server and all outbound FTP transmissions.
  • Instant messaging apps can spread infection through desktop and mobile messaging apps generally as external links that includes native messaging apps like Facebook messenger, Whatsapp and more.
  • Worms can spread through P2P file sharing networks and by any other shared device or files like a network server or USB stick.

Trojan horses :

  • If anyone has access to your system then they can easily copy trojan horse to your hard disk or a hacker can also create a trojan that mimics a program unique to your system only.
  • If someone send you an email attachment infected with trojan horse, it is likely to infect your system whenever that attachment is opened. Hackers try to make that email attachment look as legit as possible so that the user gets tricked into opening it.
  • Sometimes people who cannot find your email address can send you trojan horse through online chat box or instant messaging because it is a relatively easy way of infecting someone’s system. Hackers befriend the potential victim, lure them by sending a file that catches their attention and when the victim opens it the trojan horse is triggered.
  • You can find trojans on websites providing free software like shareware programs. On such websites trojan horse write can get anonymity and a chance of attacking as many people as they want. Website operators don’t go through every file posted which result in trojan horse slipping through the checking process unnoticed sometimes.

Virus :

  • Promotional mails are there in everyone’s mail box. Such mails comes with virus containing attachments but looks like from a legit website. So users generally open those attachments and their system gets infected.
  • Many websites like dating, gaming entertainment or adult automatically install virus and other malware into your system.
  • Hard drives containing infected disks are responsible for virus attacks and infections. Virus programs can get activated when you attach the hard drive to your computer and restart it and your data gets compromised.