Trojan is a type of malware, which works by taking a pseudo form of a legitimate software. Trojan is one of the oldest form of the malware. Using the Trojan an attacker can have an unauthorized access of the privileged data. They can modify, delete or copy the data for any malicious purpose. The Trojan can sense the network vulnerabilities and uses them to enter into the system. The working of the Trojan mainly based on the purpose of the attack (Dimitrova, 2015).