1. Trojan
Behnam Mokhtari

2. History
Trojan comes from Greek mythology, in which the Greeks battled the Trojans (people of Troy). After years of being unable to break into the fortified city, the Greeks built a wooden horse, filled it with soldiers and pretended to sail away. After the Trojans brought the horse into the city, the Greek soldiers crept out at night, opened the gates of Troy to the returning soldiers, and Troy was destroyed …

3. History
The Greek Siege of Troy had lasted for ten years. The Greeks devised a new ruse: a giant hollow wooden horse. It was built by Epeius and filled with Greek warriors led by Odeyssious. The rest of the Greek army appeared to leave, but actually hid behind Tenedos. Meanwhile, a Greek spy, Sigon, convinced the Trojans the horse was a gift despite the warnings of Laocoon and Cassandra; Helen and Deiphobus even investigated the horse; in the end, 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; during the contest with Athena over the patronship of Athens, Poseidon gave men the horse, and Athena gave the Olive Tree…

4. History 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.

5. What Is Trojan ?!
A destructive Program that masquerades as a benign Application. Unlike Viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses onto your computer …

6. What Is Trojan ?!
A program that appears legitimate, but performs some illicit activity when it is run. It may be used to locate password information or make the system more vulnerable to future entry or simply destroy programs or data on the hard disk. A Trojan is similar to a virus, except that it does not replicate itself. It stays in the computer doing its damage or allowing somebody from a remote site to take control of the computer. Trojans often sneak in attached to a free game or other utility …

7. What Is Trojan ?!
In the context of Computer Software, a Trojan horse is a malicious program that is disguised as or embedded within legitimate software. The term is derived from the classical myth of the Trojan Horse. They may look useful or interesting (or at the very least harmless) to an unsuspecting user, but are actually harmful when executed.

8. Diffrences Between Trojan ,Virus & Worm…
The most common blunder people make when the topic of a computer virus arises is to refer to a Worm or Trojan Horse as a Virus. While the words Trojan, worm and virus are often used interchangeably, they are not the same. Viruses, worms and Trojan Horses are all malicious Programs that can cause damage to your Computer, but there are differences among the three, and knowing those differences can help you to better protect your computer from their often damaging effects …

9. Diffrences Between Trojan ,Virus & Worm…
A computer virus attaches itself to a program or file so it can spread from one computer to another, leaving infections as it travels. Much like human viruses, computer viruses can range in severity: Some viruses cause only mildly annoying effects while others can damage your Hardware, Software or Files. Almost all viruses are attached to an Executable Files, which means the virus may exist on your computer but it cannot infect your computer unless you run or open the malicious program. It is important to note that a virus cannot be spread without a human action, (such as running an infected program) to keep it going.  People continue the spread of a computer virus, mostly unknowingly, by sharing infecting files or sending with viruses as attachments in the .

10. Diffrences Between Trojan ,Virus & Worm…
A worm is similar to a virus by its design, and is considered to be a sub-class of a virus. Worms spread from computer to computer, but unlike a virus, it has the capability to travel without any help from a person. A worm takes advantage of file or information transport features on your system, which allows it to travel unaided. The biggest danger with a worm is its capability to replicate itself on your system, so rather than your computer sending out a single worm, it could send out hundreds or thousands of copies of itself, creating a huge devastating effect. One example would be for a worm to send a copy of itself to everyone listed in your address book. Then, the worm replicates and sends itself out to everyone listed in each of the receiver's address book, and the manifest continues on down the line. Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much System Memory (or Network bandwidth), causing Web Servers, network servers and individual computers to stop responding. In more recent worm attacks such as the much-talked-about .Blaster Worm., the worm has been designed to tunnel into your system and allow malicious users to control your computer remotely.

11. Differences Between Trojan ,Virus & Worm…
A Trojan Horse is full of as much trickery as the mythological Trojan Horse it was named after. The Trojan Horse, at first glance will appear to be useful software but will actually do damage once installed or run on your computer.  Those on the receiving end of a Trojan Horse are usually tricked into opening them because they appear to be receiving legitimate software or files from a legitimate source.  When a Trojan is activated on your computer, the results can vary. Some Trojans are designed to be more annoying than malicious (like changing your desktop, adding silly active desktop icons) or they can cause serious damage by deleting files and destroying information on your system. Trojans are also known to create a Backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate.

12. Blended threat
Added into the mix, we also have what is called a blended threat. A blended threat is a sophisticated attack that bundles some of the worst aspects of viruses, worms, Trojan horses and malicious code into one threat. Blended threats use server and Internet vulnerabilities to initiate, transmit and spread an attack. This combination of method and techniques means blended threats can spread quickly and cause widespread damage. Characteristics of blended threats include: causes harm, propagates by multiple methods, attacks from multiple points and exploits vulnerabilities.

13. How do I avoid getting infected in the future ?!
NEVER download blindly from people or sites which you aren't 100% sure about. In other words, as the old saying goes, don't accept candy from strangers. If you do a lot of file downloading, it's often just a matter of time before you fall victim to a trojan.
Even if the file comes from a friend, you still must be sure what the file is before opening it, because many trojans will automatically try to spread themselves to friends in an address book or on an IRC channel. There is seldom reason for a friend to send you a file that you didn't ask for. When in doubt, ask them first, and scan the attachment with a fully updated anti-virus program.
Beware of hidden file extensions! Windows by default hides the last extension of a file, so that innocuous-looking "susie.jpg" might really be "susie.jpg.exe" - an executable trojan! To reduce the chances of being tricked, unhide those pesky extensions.

14. How do I avoid getting infected in the future ?!
NEVER use features in your programs that automatically get or preview files. Those features may seem convenient, but they let anybody send you anything which is extremely reckless. For example, never turn on "auto DCC get" in mIRC, instead ALWAYS screen every single file you get manually. Likewise, disable the preview mode in Outlook and other programs.
Never blindly type that others tell you to type, or go to web addresses mentioned by strangers, or run pre-fabricated programs or scripts (not even popular ones). If you do so, you are potentially trusting a stranger with control over your computer, which can lead to trojan infection or other serious harm.
Don't be lulled into a false sense of security just because you run anti-virus programs. Those do not protect perfectly against many viruses and trojans, even when fully up to date. Anti-virus programs should not be your front line of security, but instead they serve as a backup in case something sneaks onto your computer.
Finally, don't download an executable program just to "check it out" - if it's a trojan, the first time you run it, you're already infected!

15. Types of Trojan horse payloads
Trojan horse payloads are almost always designed to do various harmful things, but could be harmless. They are broken down in classification based on how they breach systems and the damage they cause. The seven main types of Trojan horse payloads are :

16. Types of Trojan horse payloads
Remote Access Trojans
Data Sending Trojans
Destructive Trojans
Proxy Trojans
FTP Trojans
security software disabler Trojans
denial-of-service attack (DoS) Trojans

17. Remote Access Trojan
Abbreviated as RATs, a Remote Access Trojan is one of seven major types of Trojan Horse designed to provide the attacker with complete control of the victim's system. Attackers usually hide these Trojan horses in games and other small programs that unsuspecting users then execute on their PCs.

18. Data Sending Trojan
A type of a Trojan horses that is designed to provide the attacker with sensitive data such as passwords, credit card information, log files, address or IM contact lists. These Trojans can look for specific pre-defined data (e.g., just credit card information or passwords), or they could install a keylogger and send all recorded keystrokes back to the attacker.

19. Destructive Trojan
A type of Trojan horse designed to destroy and delete files, and is more like a virus than any other Trojan. It can often go undetected by antivirus software.

20. Proxy Trojan
A type of Trojan horse designed to use the victim's computer as a proxy server. This gives the attacker the opportunity to do everything from your computer, including the possibility of conducting credit card fraud and other illegal activities, or even to use your system to launch malicious
attacks against other networks .

21. FTP Trojan
A type of Trojan horse designed to open port 21 (the port for FTP transfer) and lets the attacker connect to your computer using File Transfer Protocol (FTP).

22. Security software disabler Trojan
A type of Trojan horse designed stop or kill security programs such as an antivirus program or firewall without the user knowing. This Trojan type is normally combined with another type of Trojan as a payload.

23. D o S attack
Short for denial-of-service attack, a type of attack on a network that is designed to bring the network to its knees by flooding it with useless traffic. Many DoS attacks, such as the Ping of Death and Teardrop attacks, exploit limitations in the TCP/IP protocols. For all known DoS attacks, there are software fixes that system administrators can install to limit the damage caused by the attacks. But, like viruses, new DoS attacks are constantly being dreamed up by hackers.

24. How do I get rid of trojans?!
Clean Re-installation: Although arduous, this will always be the only sure way to eradicate a trojan or virus. Back up your entire hard disk, reformat the disk, re-install the operating system and all your applications from original CDs, and finally, if you're certain they are not infected, restore your user files from the backup. If you are not up to the task, you can pay for a professional repair service to do it.
Anti-Virus Software: Some of these can handle most of the well known trojans, but none are perfect, no matter what their advertising claims. You absolutely MUST make sure you have the very latest update files for your programs, or else they will miss the latest trojans. Compared to traditional viruses, today's trojans evolve much quicker and come in many seemingly innocuous forms, so anti-virus software is always going to be playing catch up. Also, if they fail to find every trojan, anti-virus software can give you a false sense of security, such that you go about your business not realizing that you are still dangerously compromised. There are many products to choose from, but the following are generally effective: AVP, PC-cillin, and McAfee VirusScan. All are available for immediate downloading typically with a 30 day free trial…

25. How do I get rid of trojans?!
Anti-Trojan Programs: These programs are the most effective against trojan horse attacks, because they specialize in trojans instead of general viruses. A popular choice is The Cleaner, $30 commercial software with a 30 day free trial. When you are done, make sure you've updated Windows with all security patches [ext. link], then change all your passwords because they may have been seen by every "hacker" in the world.
IRC Help Channels: If you're the type that needs some hand-holding, you can find trojan/virus removal help on IRC itself, such as EFnet #dmsetup or DALnet #NoHack. These experts will try to figure out which trojan(s) you have and offer you advice on how to fix it.

26. Back Orifice
A program that installs itself on a Windows machine as a server, allowing a cracker
with the client counterpart to
manipulate the machine more
completely than the user at the
keyboard. It can come in the
form of a Trojan or ActiveX control
. Back Orifice 2000 (BO2K) provides
access to Windows NT/2000 machines.
Back Orifice was created by
"The Cult of the Dead Cow" (cDc),
a hacker organization (
There are various "BO removers," which are
programs that detect and remove it…

27. Sub7
Sub7, or SubSeven, is the name of a popular trojan or backdoor program. It is mainly used by script kiddies for causing mischief, such as hiding the computer cursor, changing system settings or loading up pornographic websites. However, it can also be used for more serious criminal applications, such as stealing credit card details with a keystroke logger.
Sub7 is usually stopped by antivirus
software and a firewall, and with
popular operating systems providing
these features built in, it may become
less of a computer security problem.
However if an EXE packer is in use, it
may pass through antivirus software…

28. Sub7
It was originally designed by mobman, whose whereabouts are currently unknown. He is rumored to either have deceased or have become uninterested in continuing the project. Some claim to have spoken with him and maintain that he is not dead. At any rate, no development has occurred in several years. The website was not updated in several years (last time in April 2004), until there suddenly appeared a news message on April 6, The news was not by mobman himself, but by someone who goes under the name LaT.
Like other backdoor programs, Sub7 is distributed with a server and a client. The server is the program that victims must be enticed to run in order to infect their machines, and the client is the program with a GUI that the hacker runs on his own machine to control the server. Sub7 allows crackers to set a password on the server, theoretically so that once a machine is owned, no other crackers can take control of it.

29. Thank You