What is Trojan?

The word Trojan is derived from the ancient Trojans wars in which the Greeks gifted a wooden horse to their enemies, the Trojans.

In the world of computers, the role and procedure of a Trojan are not much different.

A Trojan is a malicious program that has been embedded inside legitimate and helpful software.

Trojans are primarily used to gain back door access to a computer.

Hackers also use Trojans to control a computer remotely. Once the Trojan has been deployed to a user’s computer, the hacker can use that computer as a bot to prepare a much large scale and massive attack on targets like servers or websites.

The hacker can steal data, store malicious files, deploy spying tools, watch the user screen and crash the user’s computer using a Trojan. The hacker can also use the Trojan to use a user’s computer as a proxy to do illegal tasks. Users having older versions of internet explorer or Google Chrome are vulnerable to such an attack due to security lapses.

A Trojan must not be mixed with a virus; it is not a virus since it does not replicate itself, nor does it spread to other computers as viruses do, but it is even more harmful to a computer than a virus. Special measures must be taken to protect computers from Trojans.

There are different kinds of Trojans like :
•    Remote Access Trojans
•    Password Stealing Trojans
•    Keylogging Trojans
•    Proxy Trojans
•    DoS attack Trojans
•    FTP Trojans
•    Software detection killers

A Trojan can be programmed to perform one of the above tasks, or a single Trojan can be designed to fulfill all of these tasks.
It depends on the complexity and functionality of the Trojan and what it was designed for.