Computer Security Threats...
Be Aware!

As soon as you go online, you face a barrage of computer security threats. The main sources are the web sites you visit, the downloads you perform (audio, audio-visual and print), the emails you receive and the crackers who listen in to your computer ports.

By being aware of these Internet risks and the effect they can have on you, your family, you can make a choice about the level of protection you install on your computer. And without the right level of protection, there will be holes in your system that could provide entry for the malware that permeates the Internet.

What level and type of protection against these computer security threats should you install on your computer?

Well, you'll find all the information you need to guard privacy and online security in my article, How To Choose Your Computer Security Threats Protection.

Now, we'll go through a brief introduction to the most prevalent computer security threats. Either scan through them all, or click on the links below for those you are particularly interested in...

  1. Viruses and Worms
  2. Trojan Horses
  3. Rootkits
  4. Crackers and Hackers
  5. Spam
  6. Web Bugs
  7. Child Security
  8. Pop-Up/Under Ads
  9. Tracking Cookies
  10. Spyware
  11. Scareware
  12. Identity Theft

1. Viruses And Worms

A virus and worm is a man-made computer program that infects a file or program and each time the infected program is run, the virus/worm is also triggered. A virus spreads itself by infecting other programs on the same computer, whereas a worm doesn't. Instead, a worm spreads itself automatically to other computers through email, over a network and via Internet Relay Chat (IRC).

The virus or worm, can,

  • Disable the computer
  • Add, modify or delete files or reformat the hard disk
  • Steal addresses held in our computer to send on virus-infected emails to our friends, colleagues, clients or customers
  • Send unsolicited bulk email (spam) to those in our mail address books and other users

2. Trojan Horses

Although Trojan horse programs are categorized as viruses, they are not true viruses, since they do not replicate. But, like viruses, they are one of the most destructive of the computer security threats and are favored by crackers and spyware writers.

Trojans are one of the sneakiest of the online risks. They are often downloaded on the back of a free program (freeware) that has some value to the user -- a free game, software program or music, for instance.

A Trojan installed on a computer allows that PC to be entered via a 'backdoor' by any remote user that has the access code to the Trojan.

The remote attacker can enter the computer undetected to access or destroy any information stored. Alternatively, the Trojan can be programmed to automatically send any information on our PCs back to the attacker, such as, credit card details and passwords.

3. Rootkits

Rootkits are not destructive in their own right... but they are designed to conceal the presence of malicious programs and so they are one of the most difficult of the computer security threats to detect.

As with any malware, such as viruses, worms, Trojans and spyware, rootkits get onto our computers by various means, such as through spam attachments being opened, on the back of free downloads or planted by crackers who have breached computer defenses.

One of the most common and worrying uses of rootkits is to launch spam and denial of service (DOS) attacks against other computers or networks. Another use of rootkits is to hide Trojans, so an intruder can easily use it to extract data from your computer, as mentioned in the computer security threats above.

4. Spyware

Spyware has surpassed viruses and tops the computer security threats facing us today. Most estimates report that 80-90 percent of computers are infiltrated by spyware.

The software is installed on our hard drive through spam, drive-by downloads, freeware, shareware and the P2P (peer-to-peer) file sharing programs, like Imesh and Bearshare. It gathers our personal information and computer habits and this private information is transmitted through our Internet connection to a third party -- usually without our knowledge or consent.

More aggressive forms of spyware can install themselves through "drive-by downloads", where an invasive program is invisibly downloaded to your computer. It can be initiated by simply visiting a Web site or viewing an HTML e-mail message.

There are two categories of spyware...

  1. Surveillance or monitoring spyware can scan our hard drive and search programs for sensitive information like credit card, bank information and personal and our Internet activity. More and more companies are installing spyware to watch us at work to check that we are not using the company network to surf prohibited sites or spending too much time dealing with personal email.
  2. Advertising spyware logs information, such as our name and passwords, our browsing and Internet usage habits, online purchases and email addresses. And, of course, it downloads advertisements... lots and lots of advertisements!

5. Spam

Spam is defined in as, "Unsolicited e-mail, often of a commercial nature, sent indiscriminately to multiple mailing lists, individuals, or newsgroups; junk e-mail".

Spammers peddle pornography, sexual aids, diet pills and get-rich-quick schemes... in fact, anything that has a perceived value. It is no longer just a frustration, nuisance and time-waster... it has now become one of the major computer security threats.

Much of this spam has malicious code or malware incorporated into it, which is triggered by opening the email or even previewing it in our email program.

If you're not quite convinced that spam is dangerous, consider the following...

  • 80 percent of spam e-mail messages originate from home computers! They have been secretly taken over by spammers and are known as zombie PCs. Spammers and cybercriminals can control thousands of these zombies, which together form a "bot network"
  • Identity theft and fraud and phishing via spam email is growing in frequency
  • 95 percent of viruses are sent through email
  • Spam is often used to deliver spyware -- probably the top of the computer security threats.

6. Web Bugs

A web bug is an image file, usually 1x1 pixel, hidden on a web page or in an HTML e-mail. They are usually downloaded in spam and they can be on any webpage we visit.

A web bug tells a spammer when an e-mail has been opened and tells marketers what advertisements and web pages we have viewed. The bugs can discover key details about our system that are very useful to hackers. They also transmit the IP (Internet Protocol) address of all readers of an e-mail to a spammer -- really secretive computer security threats!

7. Child Security

Some form of parental control is required to prevent children being funneled to inappropriate web sites and predators on the Net, such as in chat rooms.

A survey showed that more than 80 percent of children said they receive "inappropriate" spam every day, with half of those admitting they felt "uncomfortable and offended" when seeing them.

8. Pop-Up/Under And Banner Ads

A pop-up ad appears as a separate window on top of the web page we are viewing, whereas pop-under ads appear under the page being viewed, becoming visible when the web page is cancelled. A banner ad is immediately on view on a web page and can be animated or stationary.

Popups/unders/banners can be an annoyance by interfering with our viewing pleasure but some of these ads can also join the serious computer security threat -- they can carry Trojans, spyware or browser hijackers. The malicious code is generally activated by clicking on the ad... the malware being installed on our computer through vulnerabilities in our browser and a process known as a drive-by-download.

9. Tracking Cookies

When we browse web sites, the web server for the web site sends a cookie to our web browser (e.g. Internet Explorer), which it then stores on our computer hard drive.

Cookies are small text files containing information that identifies each user. When you move to another page or return to the site at a later time, the web server asks your browser for the cookie, so it can 'recognize' who you are.

Cookies are often used by advertisers to track our browsing and buying habits and create profiles of users for targeted marketing. Multiple sites may read from the same cookie and share the information or, they can sell it on without the knowledge or consent of the user.

Although not one of the serious computer security threats, cookies are a privacy risk.

10. Crackers And Hackers

The term "hacker" is not one of the computer security threats . It's a misused term as it refers to computer enthusiasts who enjoy learning everything about a computer system. We should really be referring to a "cracker" to describe those who break security on a computer system.

Crackers run programs that scan computer ports over the Internet to work out which ports are accessible. If our computer shows up in one of these scans, the cracker may decide to enter our PC. Crackers favorite targets are the home and home office computers connected by broadband to the Internet. Because the connection is always open, there is more opportunity to locate these computers with their scanners.

Alternatively, crackers may just exploit weaknesses that have not been 'patched' in the computer's operating system in order to gain entry. As discussed above, Trojans are another way crackers use to gain access to our PCs.

Besides the potentially valuable information they can obtain from our PCs, these intruders also want our hard disk space and Internet connection. So, we add to the computer security threats by sending out spam or attacking other computers on the Internet... and all this can be done without our knowledge!

11. Scareware/Ransomware

Scareware is an overall term for ransomware, rogue scanner, fraudware and deceptionware. It covers any malware designed to generate a pop-up or window, which deceives by warning a non-existent major issue has occurred on the computer and scaring the recipient into paying to resolve the problem.

Not only will your money be taken, but when making payment, your credit card details will be stolen. Scareware often contains a key logger to record your personal details for ID theft and can remotely take control of your PC for sending spam to other computers!

12. Identity Theft

Internet identity theft is one of the major computer security threats, which continues with it's logarithmic growth. A third party gains our personal information to adopt our identity to make purchases for illegal documentation, to access our bank accounts and to use our credit cards etc.

This information is obtained by 'social engineering', usually using spam for phishing or pharming. The theft can be directly from our computers using Trojans, spyware and crackers, as discussed above.


Supporting Articles

  1. Computer Security Vulnerabilities... Why Is the Home User Targetted?
  2. See These Tips Before Choosing Your Software

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