Hacking May Occur Through a Virus
After becoming increasingly popular during the first years of the 21st century, gaining access to a machine through clandestine virus installation has become one of the most widespread hacking vehicles ever recorded. This form of hacking works by injecting a few specialized lines of code into an otherwise harmless executable file. The infected file is then made available for download on the Internet, and downloaders subsequently become infected with the virus. As web technology advanced, some hackers discovered an Internet security flaw that allowed them to install the malicious program directly onto a user's computer when the user simply visited a certain website. By exploiting security holes in web browsers such as Internet Explorer or Firefox, the program could be quietly downloaded and installed in the background. Once the program infected the machine, the hacker could easily access the machine, take over the machine, or use the infected computer to send bulk advertising (spam) without fear of punishment.
Hacking May Occur Through an Unsecure Wireless Network
Rather than use malicious lines of programming code to break in to someone's computer, some hackers prefer to simply drive around looking for open wireless networks. Home and commercial wireless routers offer several choices of security key configuration to prevent unauthorized access, but the routers do not come with security enabled by default, so some some users never enable it. Hackers exploit this lack of security by simply scouting around for open, unsecured wireless connections (this activity is known as "WarDriving" in a nod to the 1982 hacker film "WarGames"). Once the hacker is connected to the unsecured network, he has a direct connection to any other computer on that network and needs to bypass only very basic security in order to access sensitive data.
Hacking May Occur Through a Brute-Force Attack
Brute-force attacks, possibly the oldest form of hacking, involves simply guessing a username/password combination in an attempt to gain unauthorized access to a computer, system or network. Repeatedly entering commonly used passwords such as birthdates and pet names can become very tedious, so some hackers employ automatic scripts--known as robots, or bots for short--to continually attempt access to a restricted machine. These bots can be programmed with tens of thousands of dictionary words and variations thereof, raising the odds that a hacker will eventually gain access. Modern computer systems and networks attempt to combat this form of attack by denying access and disabling accounts after a specified number of incorrect login attempts.