Unauthorized access is age old. It began with the Romans and their poor, landless citizens attempting to infiltrate colossal Roman castles. The concept within Internet hacking is relatively similar, all based around a single theme: information. Those with information, therefore, have access and power, even if it is confined to one particular network, for a short amount of time. The importance, then, of hacking, can be said to include information and power. Gravy... This begs the question of how these hackers gain access to networks. Some common tricks include password deciphering, buffer overflows, scripts and DoS attacks. The purpose of this article is to introduce you to what exactly hackers do to gain access, and to quench the steadfast intrigue of these concepts.
What are hackers? What are crackers?
Definitions for these two terms vary, but suffice it to say that hackers are those exceptionally knowledgeable computer users, often skilled in programming languages and Internet logic. The term hacker, then, can conceivably be used with either a positive or negative connotation. Throughout the years, this term has gained much momentum to the negative. Now, the term often means to gain access to a network, after hacking their way in. The term crack means to break into a computer system. Hackers wish to differentiate the two terms, as hackers are said to strive towards information for the purposes of pranks, or web site 'modification'. Crackers, on the other hand, have a specific purpose to break into secure systems, capture the password(s) and wreak havoc on the machine. Since these two terms are often used reciprocally, this article will exercise the terms hacker and hack, opposed to cracker and crack.
Efforts to gain passwords
SIMPLE INVESTIGATION
Let's get into the meat and potatoes of what hacking is all about: capturing the often illusive password. By their nature, passwords should be illusive, but hackers contrive methods and techniques to gather them, and use them for their own purposes within a network. The password is the lowest, but ultimately the most important, step in the hacking totem pole. Once a password is compromised (or seized), hackers use it to realize additional rights and privileges within the system.
So, how are passwords seized? Regardless of how secure the network itself is, there are always insecurities, and that includes the actual users of the network (or, Mr. Do Mas). Sure, hackers can use sophisticated password utilities to guess passwords on a system, but oftentimes a little investigation provides what the hacker is looking for. Believe it or not, a major source of password compromise is the simple laziness of users. Users write the passwords down on little Post-It notes and place them within their desk. Users give their passwords to others. Passwords are printed out on pieces of paper that are often thrown out whole. A little rummaging through an office and its waste can surface more information than you might imagine.
Hackers also use a technique known as social engineering. They may call up a network administrator, pose as a confused network user and claim that they lost his or her password. This works way too often and many times is the first thing that hackers try.
TROJAN HORSES
The war between the Achaeans and the Trojans continued for 10 long years. After the death of Achilles (known as the greatest warrior among the Greeks), the Achaeans constructed a wooden horse and filled it with warriors and brought it into the city of Troy. Once inside, the warriors exploded from the wooden horse and destroyed the city; or so the legend goes. A trojan horse in computer terms means essentially the same thing, a seemingly harmless computer program infiltrates the computer system, while malicious routines are being executed behind the scenes. One of the first trojan horses was a program that impersonated a login box. Once the user enters his or her password, they are saved in a location that the hacker has access to.
This type of trojan horse is commonly installed on library computers, or an otherwise public computing environment. Trojan horses are often more disguised than a simple login prompt. Windows and Linux system commands, for example, are susceptible to manipulation. Without getting into technicalities, the windows command edit can be compromised and instructed to launch a malignant batch file behind the scenes, deleting or even adding user accounts with administrator privileges. Remember that a trojan horse is an executable file, which can be recognized with the .exe, .vbs, .com, etc extensions. A trojan horse sent through e-mail can often be found by noticing an extension like .txt.vbs.
PACKET SNIFFERS
Network data travels through network media in variable sized packets. These packets, of course, are never seen in their raw form, as a series of network protocol rules convert such packets to data that applications can interpret and display. However, before data packet arrives at the recipient's computer, the packet can be snatched out of the media by packet sniffing software. Because such utilities, like Telnet or SNMP, were designed to send passwords over network media in plaintext, or unencrypted form, passwords can be easily compromised using this method.
Note that packet sniffers are capturing utilities, and cannot be used to actually modify any of the seized data packets. Sniffers can capture data within multiple protocols, like IP (Internet Protocol), UDP (User Datagram Protocol) and TCP (Transmission Control Protocol), allowing a single application to function well within a wide array of computing environments. Passwords are not the only way hackers gain access to networks. Next, we will take a look at buffer overflows, and what it provides to hackers
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