Here is How Hackers Perform a SQL Injection Attack

A “SQL injection” (SQLI) attack is an exploit that takes advantage of poor web development techniques and, typically combined with, faulty database security. The result of a successful attack can range from impersonating a user account to a complete compromise of the respective database or server. Unlike a DDoS attack, an SQLI attack is completely and easily preventable if a web application is appropriately programmed.

Executing the attack
Whenever you login to a web site and enter your user name and password, in order to test your credentials the web application may run a query like the following:


SELECT UserID FROM Users WHERE UserName='myuser' AND Password='mypass';

Note: string values in a SQL query must be enclosed in single quotes which is why they appear around the user entered values.

So the combination of the entered user name (myuser) and password (mypass) must match an entry in the Users table in order for a UserID to be returned. If there is no match, no UserID is returned so the login credentials are invalid. While a particular implementation may differ, the mechanics are pretty standard.

So now let’s look at a template authentication query which we can substitute the values the user enters on the web form:

SELECT UserID FROM Users WHERE UserName='[user]’ AND Password='[pass]’

At first glance this may seem like a straightforward and logical step for easily validating users, however if a simple substitution of the user entered values is performed on this template, it is susceptible to an SQLI attack.

For example, suppose “myuser’–” is entered in the user name field and “wrongpass” is entered in the password. Using simple substitution in our template query, we would get this:

SELECT UserID FROM Users WHERE UserName='myuser'--' AND Password='wrongpass'

A key to this statement is the inclusion of the two dashes (--). This is the begin comment token for SQL statements, so anything appearing after the two dashes (inclusive) will be ignored. Essentially, the above query is executed by the database as:

SELECT UserID FROM Users WHERE UserName='myuser'

The glaring omission here is the lack of the password check. By including the two dashes as part of the user field, we completely bypassed the password check condition and were able to login as “myuser” without knowing the respective password. This act of manipulating the query to produce unintended results is a SQL injection attack.

Protection: Install Anti-Virus Software

Anti-virus software searches for evidence of the presence of viral programs, worm, bombs, and Trojan horses by checking for the characteristic appearances or behaviors that is typical of these programs. When found the program logs its discovery, its type, often its name or an identifier, and it potential for damage. The anti-virus software then eliminates or isolates/quarantines the infected files. For the individual, commercial software is relatively inexpensive; however, there are free anti-virus programs available.

Since new viruses appear almost daily with new code it is imperative that you update you antivirus program often to keep up with these threats; therefore, make sure to set your program to update automatically. To avoid the annoyance of computer slowdown schedule full scale scans late at night.

The same is true for your Windows Operating System. Very often, your OS is where hackers discover the holes to exploit. Of course, in an ever-continuing battle, this software is continuously updated with security patches.

Finally, secure your wireless network with a router that has a built in firewall. Almost all wireless routers are set to no security when first installed. Log into the router and at least set it to basic security with a strong password to replace the factory setting that any hacker knows. A firewall or router that is not configured properly or non-existent allows hackers to scan passwords, e-mails, or files that cross your network connection.

Protect Your Computer: Avoid Computer Holes/Vulnerabilities

Install only trusted software and delete unknown emails. 

If you have any doubt about a piece of software's function, do not install it. If you receive e-mails from random people's names, resist your curiosity and do not open it, just delete it.

Under no conditions download or open attachments from anyone that you do not know and even then be cautious. 

Banks and most companies that create online personal accounts will not send you attachments. 

If they do, it is probably best to go to the company site and request the download or at least see if it is legitimate. Avoid adult web sites, a hacker's paradise.

Whether in your e-mail or online, do not click on ads. 

If the ad is of interest, find the site. Be careful with what you physically put into your computer. This is especially true for shared R/W CDs, USB hard disks, or flash drives. 

This is an easy path for a virus to follow from computer to computer.

Hacker Tools

There now are more than 100,000 known viruses with more appearing virtually daily. The myriad of hackers and their nefarious deeds can affect any computer owner whether an occasional home user, e-mailer, student, blogger, or a network administrator on site or on the internet. No matter your level of computer use, you must protect your computer, business, or even your identity. The best way to know how to protect your computer is to understand the hacker's tools and recognize their damage.

What is Hacking?

During the 1990s, the term "hacker" originally denoted a skilled programmer proficient in machine code and computer operating systems. In particular, these individuals could always hack on an unsatisfactory system to solve problems and engage in a little software company espionage by interpreting a competitor's code.

Unfortunately, some of these hackers also became experts at accessing password-protected computers, files, and networks and came to known as "crackers." Of course, an effective and dangerous "cracker" must be a good hacker and the terms became intertwined. Hacker won out in popular use and in the media and today refers to anyone who performs some form of computer sabotage.

Viruses, Exploits, Worms, and More

The term computer "virus" originated to describe a computer code that is inserted into a computer. Depending on the hacker's intent, the design of a virus can merely be an inconvenience or have very serious consequences up to a potential catastrophe.

Generally, a virus is a piece of software, a series of data, or a command sequence that exploits a bug, glitch, or vulnerability. Each example is appropriately termed an "exploit." An exploit causes unintended or unanticipated behavior to occur in a computer system or applications while propagating itself within the computer.

An exploit and operates through a network security vulnerability or "hole" without previous access to the vulnerable system is a "remote" exploit. An exploit that needs prior to a system is termed a "local" exploit. These are usually intended to increase the hacker's access privileges beyond those granted by a system administrator.

Worms are simply viruses that send copies over network connections. A bomb resides silently in a computer memory until set off by a date or action. A Trojan horse is a malicious program which can be reproduced by CD or e-mail.