Trojans have been around for quite a long time. Trojans are essentially programs that appear to perform one function while actually performing another. Damages that Trojans can cause on your computer include transmitting viruses and installing backdoor programs that allow surreptitious entry to the compromised system.

Types of threats that Trojans pose are deleted files, uploading and downloading data, keystroke logging, mass spamming from your computer and crypto viral attacks. Trojans usually carry ‘payloads'. This is the package that the Trojan was sent to deliver to your system.

Payloads may contain key loggers, viruses, data destruction, downloader's, server Trojans, (i.e. proxies, ftp, irc, etc.) security software disablers, and other malicious software. These kinds of payloads are meant to cause damage, open ports on your system for unauthorized access and in some cases spread viral infections. Because Trojans are programs crafted by programmers, inherently, there's no limitation to what a Trojan is capable of.

This is the nature of coding. If you are an experienced programmer you are only limited by your resources and imagination. With that said the threat grows exponentially with the advent of newer, faster, technology.

Protecting against Trojans is a never ending battle as with viruses. Because of their popularity and capabilities Trojans are always being coded and release to the public. Entire databases of exploits are freely available on the internet and are rather easy to use.

If you understand your operating system and perform a little research it is completely possible to master deploying a Trojan to a network. Trojans have been implemented since the UNIX operating system has existed. Many Mac users argue that it is easier for Windows to catch a virus or Trojan infection. This is simply not true. Any user who is ignorant as to operating system security not only poses a threat to himself but to others.

The reason being, in not understanding how to protect your machine you cannot administer the system properly. One certainly cannot create or

configure policies that harden the operating system. This leads to security holes that are trivial in nature but carries huge repercussions.

Marketing contributes to the misconception that one system is more susceptible to attacks than another and this leads to lackadaisical attitudes in security.

The nature of a Trojan is to exploit some security hole or holes in an operating system. After the system has been exploited the payload of the virus could spread to other computers that interact with the infected computer.

Best practices when configuring any operating system is to turn off any unnecessary services, closed unused ports, and secure higher unused ports. These are the first places Trojans, worms look to exploit.

Next install anti-virus and firewalls on the computer. *NIX & Windows systems come with pre-installed firewalls. Despite the argument that UNIX is safer than windows it is not without its flaws. It is always wise to implement some sort of anti-viral support just for safety's sake.

In case of an attack the anti-virus program should automatically catch it and contain it before it executes. But technically the attack occurred because the user posed an opportunity.

By removing all opportunities to penetrate the operating system there can be no infiltration. Therefore, prevention is always the best method of defense.