The Greek siege of Troy had lasted for ten years. The Greeks devised a new ruse: a giant hollow wooden horse which was filled with Greek warriors led by Odysseus. The rest of the Greek army appeared to leave, but actually hid behind Tenedos. Meanwhile, a Greek spy, Sinon, convinced the Trojans that the horse was a gift the Trojans accepted the gift.
In ancient times it was customary for a defeated general to surrender his horse to the victorious general in a sign of respect. It should be noted here that the horse was the sacred animal of Poseidon.
The Trojans hugely celebrated the end of the siege, so that, when the Greeks emerged from the horse, the city was in a drunken stupor. The Greek warriors opened the city gates to allow the rest of the army to enter, and the city was pillaged ruthlessly, all the men were killed, and all the women and children were taken into slavery.
this is the history which surrounds the Trojan virus of today!
The Trojan Horse (Computing)
In the context of computer software, a Trojan horse is a program that installs malicious software while under the guise of doing something else. Though not limited in their payload, Trojan horses are more notorious for installing backdoor programs which allow unauthorized remote access to the victim’s machine by unwanted parties – normally with malicious intentions. Unlike a computer virus, a Trojan horse does not propagate by inserting its code into other computer files. The term is derived from the classical myth of the Trojan Horse. Like the mythical Trojan Horse, the malicious code is hidden in a computer program or other computer file which may appear to be useful, interesting, or at the very least harmless to an unsuspecting user. When this computer program or file is executed by the unsuspecting user, the malicious code is also executed resulting in the installation of the malicious Trojan horse program.
Example of a Trojan horse
A simple example of a Trojan horse would be a program named “waterfalls.scr” which claimed to be a free waterfall screensaver. When run, it would instead open computer ports and allow hackers to access the user’s computer remotely.
Types of Trojan horse payloads
Trojan horse payloads are almost always designed to do various harmful things, but can also be harmless. They are broken down in classification based on how they breach and damage systems. The nine main types of Trojan horse payloads are:
Proxy Trojan (disguising others as the infected computer)
FTP Trojan (adding or copying data from the infected computer)
security software disabler
denial-of-service attack (DoS)
URL trojan (directing the infected computer to only connect to the internet via an expensive dial-up connection)
Some examples of damage are:
erasing or overwriting data on a computer
encrypting files in a cryptoviral extortion attack
corrupting files in a subtle way
upload and download files
allowing remote access to the victim’s computer. This is called a RAT (remote administration tool)
spreading other malware, such as viruses: this type of Trojan horse is called a ‘dropper’ or ‘vector’
setting up networks of zombie computers in order to launch DDoS attacks or send spam.
spying on the user of a computer and covertly reporting data like browsing habits to other people
logging keystrokes to steal information such as passwords and credit card numbers
phishing for bank or other account details, which can be used for criminal activities
installing a backdoor on a computer system
opening and closing CD-ROM tray
harvesting e-mail addresses and using them for spam
restarting the computer whenever the infected program is started
deactivating or interfering with anti-virus and firewall programs
deactivating or interfering with other competing forms of malware
Well Known Trojan Horses
- Pest Trap
- Vundo trojan
- Gromozon Trojan