In computing, the trojan horse is any malware that misleads users of its true intent. Now, what is malware? This is the logical question that one would ask. Malware is software intentionally designed to cause damage to a computer, server, client, or computer network. A wide variety of malware types exist including computer viruses, worms ransomware, spyware, adware, rogue software, scareware, and the trojan horse. The term trojan horse is derived from the Ancient Greek story of the deceptive trojan horse that led to the fall of the city of Troy.
Though it is not clear where or when the concept and this term for it i.e. trojan horse was first used, but the first Unix manual published in 1971, mentioned clearly all the readers it’s meaning unambiguously. Also, the US air force report published in 1974, shows another early reference when the mention of analysis of vulnerability is carried out in Multics computer systems.
How Trojan came to the limelight:
Further, it was made popular by Ken Thompson, in the 1983 Turing award acceptance lecture “Reflections on trusting trust”. Ken simply asked a question that to what extent should one trust the statement that a program is free of Trojan horses? He also answered his question by saying that it is both important and advisable to trust the people who created and wrote it rather than those merely making statements. He also revealed that he knew the possible existence of trojan horses from a report on the security of Multics.
Where & how does it exist?
Trojan viruses, in this way, may require interaction with a malicious controller (not necessarily distributing the trojan) to fulfill their purpose. It is possible for those involved with Trojans to scan computers on a network to locate any with a trojan installed, which the hacker can then control.
Some trojans take advantage of a security flaw in older versions of Internet Explorer and Google Chrome to use the host computer as an anonymizer proxy to effectively hide Internet usage, enabling the controller to use the Internet for illegal purposes while all potentially incriminating evidence indicates the infected computer or its IP address. The host’s computer may or may not show the internet history of the sites viewed using the computer as a proxy.
The presence of trojan horse is universally transcending geographical, political, and organizational boundaries including countries like the US, Germany, Switzerland, private, public & government.