Viruses, Worms and Trojan horse are types of malicious programs that infiltrate a system and can cause damage to it.
VIRUS, WORM AND TROJAN HORSE
Viruses, Worms and Trojan horse are types of malicious programs that infiltrate a system and can cause damage to it. The most common misconception about these malicious programs is that they are the same thing. The fact however is that, although these words(Virus, Worms and Trojan horse) are often used interchangeably, they are different from one another. What specifically sets them apart is the way they attack, spread and replicate.
Each of these types of malware has its own specific characteristics and behaviors, and they can cause different types of harm to a computer or network. Below are some of the differences between these malicious programs, that is, viruses, worms and Trojan horse.
A computer virus is a type of malicious software, or malware, that spreads between computers and causes damage to data and software. Whereas, a worm is like a computer virus by its design but is a sub-class of a Virus or Trojan Horse. It spreads from computer to computer, but unlike a virus, it has the capability to travel without attaching to a host program and can run independently. On the other hand, a Trojan Horse is any type of malware that misleads users of its intent, like a destructive program that appears as a genuine application or software program and steals sensitive information/data from a user's system and sends it to another location across the network.
Also, viruses cannot be operated remotely since they are installed on the target machine or by the user inadvertently. Whereas, worms can be controlled by the remote because they can open a back door to the host. Trojan Horse can also be operated remotely, much like worms via the network.
Viruses replicate by creating their own files on an infected system, attaching themselves to a legitimate program, infecting a computer's boot process or infecting user documents but they can't replicate themselves independently without human intervention. Whereas, worms are self replicating codes that can duplicate themselves to spread to uninfected computers. They spread through the internet or through LAN (Local Area Network) connection and often do this by exploiting parts of an operating system that are automatic and invisible to the user. Trojan horse on the other hand, do not replicate.
The spreading rate of viruses are moderate. While, the spreading rate of worms are faster than virus and Trojan horse. But, the spreading rate of Trojan horse is slow in comparison of both virus and worms.
The primary objective of viruses are to alter or erase system data. Whereas, the primary objective of worms are to degrade system performance and slow it down by eating system resources. Trojan horse on the other hand, is to steal the information on the system.
Viruses are executed via executable files. Whereas, worms are executed via weaknesses in system but, trojan horse executes through a program and interprets as utility software
In conclusion, viruses, worms and trojan horse are malicious programs that are difficult to deal with once they infiltrate a system. Despite their differences in terms of attack, replication and propagation, they pose a serious threat to users' systems. Hence, it is always a security precaution to have a robust antivirus solution and firewall installed on systems or devices in order to prevent their infiltration.