by Guard Privacy & Online Security  17 November 2011

Malicious hackers want to gain access to our PCs… but how does that affect us? What are the effects of computer hacking?


Well, we’re attacked either to cause damage, steal our information, use our PC as a spam machine, or for Denial Of Service (DOS) attacks on other computers.

Another reason for us to be concerned is that the favorite targets of hackers are home and home office computers, connected by broadband to the Internet. This is because the connection is always open, and so there is more opportunity to locate these computers with scanners.

The sections that follow will provide the answers to…


  1. The difference between hackers and crackers
  2. Why do hackers attack us?
  3. How do hackers attack us?
  4. How to tell we are a hacking victim
  5. How do we protect ourselves?
  6. Other relevant articles


1. What Are The Effects Of Computer Hacking?…
The Difference Between Hackers And Crackers


The term ‘hacker’ is a mis-used term and we should really be referring to a ‘cracker’.

When used correctly, ‘hacker’ refers to computer enthusiasts who enjoy learning everything about a computer system, pushing the system to its highest possible level of performance. Some use their skills for business, developing penetration tools to analyze a customer’s networks for security vulnerabilities.

‘Cracker’, on the other hand, is the term used to describe those who break security through a vulnerability on our system. The name was given by hackers to counter journalistic mis-use of the word ‘hacker’.

Crackers seek to ‘crack’ or gain unauthorized access to computers to steal what we have stored on our computers, such as credit card numbers, bank account details, address books or other personal, financial or business information.

Because of the understanding amongst most people that hackers are malicious, for the purposes of this article, I will use ‘hacker’ and ‘cracker’ interchangeably to mean intruders with malicious intent.

2. What Are The Effects Of Computer Hacking?…
Why Do Hackers Attack Us?


For some, hacking may just be a hobby to see how many computers or networks they can crack.

For others, there is malicious intent behind their escapades, like stealing…


    • Client or customer information or other business data



    • Credit card details and social security numbers, for identity fraud or theft



    • Passwords for access to our online bank, ISP or web services



    • Email addresses, which may be used for spamming



  • Children’s names, photographs, ages or other of their personal details held on the computer



Crackers may also want our computer resources for Distributed Denial of Service (DDoS) attackson other computers or Web sites.


For instance, it’s been shown that crackers will sell on the details of compromised computers to spammers.

In turn, the spammers will use the PCs for DDoS attacks on, for example, anti-spam organisations. They bombard the organization’s web site with massive amounts of traffic, causing the organizations servers to become so overloaded they crash. The Website, and often the organization, can no longer function… the objective of the DDoS attack being accomplished.

Threats of such DDoS attacks have been made against financial institutions and business corporations… the attack not being launched if a sizeable ransom is paid! And, yes, a number of them have been paid.

They may also use these PCs as ‘spam zombies’ or ‘spam bots’ — literally sending out torrents of spam from these machines without the users’ knowledge.

Often, the user may only become aware of what’s going on when they are contacted by their ISP (Internet Service Provider), either about the spam complaints received or their excessive bandwidth useage.

The first successful prosecution of this type of cracking operation in the USA was in 2005. A 20-year-old American, Jeanson James Ancheta pleaded guilty in a Los Angeles court to charges of conspiring to violate anti-spam and computer misuse laws, and fraud.

He admitted hijacking about half a million computer systems and using them to send out spam. In entering his guilty pleas, Mr Ancheta also admitted to selling access to his botnet to firms which fed pop-up ads to the infected computers.

Among the machines infected were US military computers in California and in Virginia!

3. What Are The Effects Of Computer Hacking?…
How Do Malicious Hackers Attack Us?


Computer hacking uses a number of common tools to gain entrance to our system. Let’s take a look at some of them…


    1. What Are The Effects Of Computer Hacking?… Port Scanners
      Computer cracking can involve port scanners — an automated tool to systematically try to connect to every port on a computer. 

      Port scans do have some legitimate uses, such as for testing our firewall security. However, hackers use them for scanning random blocks of Internet addresses looking for unprotected computers with unguarded ports.

      If our computer shows up in one of these scans — because we have a poorly configured firewall or no firewall at all– the malicious hacker may decide to enter our PC.

    1. What Are The Effects Of Computer Hacking?… Malicious Programs
      Hackers use backdoors — such as Trojan horses and rootkits — viruses, and worms to compromise our systems. 

      Trojan horses are designed to appear to do one thing, such as a free game, but really do something malicious. They are often downloaded in a piece of freeware. A Trojan can be used to create a backdoor, allowing a hacker to gain access later.

      A rootkit is a piece of software that can be installed in a similar way to a Trojan and hidden on our computer without our knowledge.

      Rootkits are not necessarily malicious, but they may hide malicious activities. Attackers may be able to access information, monitor our actions, modify programs, or perform other functions on our computer without being detected.

      A virus is a self-replicating program that spreads copies of itself to other programs on the computer it has infected.

      A worm is also a self-replicating program, but it can spread copies of itself to other computers. It may carry a malicious program, such as a Trojan horse, which gives a hacker a backdoor entrance to our PC.

    1. What Are The Effects Of Computer Hacking?… Vulnerability Scanners
      Computer hacking can use vulnerability scanners to check a computer for security weaknesses, such as those common on Windowsoperating systems. When a vulnerability is found, the hacker knows exactly what to target to hack the system. 

      Take, for example, a hacker armed with a laptop loaded with searching software and an omni-directional antenna. He/she can car-cruise down local neighborhoods and business parks to detect the locations of wireless network access points, or hotspots.

      The hacker will make note of the site, return at a later time, and hack into the network to search for vulnerabilities. This practice is known as “wardriving” or “drive-by hacking”.

  1. What Are The Effects Of Computer Hacking?… Password Cracking or Sniffing Programs
    A password cracking program guesses users’ passwords, whereas a sniffer program watches information passing through the Internet. 

    The aim of using these computer hacking programs is to obtain usernames and passwords for unauthorized access.


4. What Are The Effects Of Computer Hacking?…
The Tell-Tale Signs


What are the effects of computer hacking that let us know we are the victims of computer hacking? Some tell-tale signs are…


  • An unexplained decrease in hard drive space availability
  • Files unexpectedly appear or grow in size
  • Files unexpectedly disappear or are modified
  • Sudden computer or network performance changes
  • Frequent crashes
  • Strange messages or dialog boxes appearing on our screen
  • Our computer or router Internet data transfer light blinking, when we’re not accessing the Net


5. What Are The Effects Of Computer Hacking?…
How Do We Protect Ourselves?


Preventative measures are the first steps towards safeguarding our system and network. Here are some important steps to take:


    1. What Are The Effects Of Computer Hacking?… Install A Firewall

      Firewalls prevent access to our computer from the outside, so that only those that we give permission to can connect to our system from the Internet. 

      The more effective and secure firewalls also ensure outbound control, watching for and preventing a Trojan, spyware or any other program from communicating out of our computer, unless we provide permission. For the best firewalls, check out Free And Buy Firewalls Reviewed.

      Windows XP users, please take noteMicrosoft Windows Firewall only watches inbound connections and ignores outbound traffic.

      Although this firewall will detect cracker scans for vulnerabilities, it will not prevent malicious applications, such as Trojan horses, rootkits, worms and viruses, from using our Internet connection to send out our sensitive information.

      For further information, take a read of Beware Windows Firewall



    1. What Are The Effects Of Computer Hacking?… Change Passwords
      To counter password cracking or sniffing, change default passwords in your software programs as soon as possible. Use complex passwords and make sure to change them on a regular basis.



    1. What Are The Effects Of Computer Hacking?… Keep Patches Up-To-Date
      Our operating system and other software should be patched as soon as updates are released. Maintaining the most recent versions of software and operating systems will help block hackers from getting through any vulnerabilities.



  1. What Are The Effects Of Computer Hacking?… Install Antivirus Software
    All our computers should be running the most recent version of an anti-virus program. The program should be set for automatic updates to ensure the latest virus, worm and Trojan definitions.


6. What Are The Effects Of Computer Hacking?… Other Relevant Articles





    • Free And Buy Firewalls Reviewed. Imagine what it would feel like to connect to the Internet and know you are fully protected from intruders. Well, it’s within your grasp!



    • Free Or Buy Firewalls? The Pros And Cons. There are three “types” of firewall to choose from. We can buy firewalls — software and hardware — or we can use a free firewall download. But which type is best for our computer?