How To Secure Your Personal PC



Photo by Don Hankins

(Note: while this article contains much general information, the scope of solutions and resources is limited to Windows-based computers.)

There are only two words you need to know about securing your personal computer: imaging and backup. An image is a snapshot of your primary hard drive at a specific point in time. If you create and maintain pristine images of your hard drive, you can “rollback” (restore) your system to any one of these last known good points in time. Unfortunately, a rollback also erases whatever good data may have existed on the hard drive, such as your current projects, downloads and photos. For this reason, the second part of securing your personal computer involves setting up a robust backup routine.

When you are ready to secure your personal computer, refer to a professional computer technician for practical tips. You should ask for ideas on the creation of the initial image, the best time to make a new image and how to implement a workable backup strategy.

What Is Personal Computer Security?

A practical definition of computer security can be found at albion.com :


“In the spirit of practicality, I like the straightforward definition promulgated by Simson Garfinkel and Gene Spafford in Practical UNIX & Internet Security: “A computer is secure if you can depend on it and its software to behave as you expect.”4 In essence, a computer is secure if you can trust it. Data entered today will still be there tomorrow in unaltered form. If you made services x, y, and z available yesterday, they’re still available today.”

 

What Are Some Threats to Personal Computer Security?


Click on the security mind map below to see the full-size image in a new browser window. Be sure to enlarge it by clicking on the image in the window.

This is by no means a complete and exhaustive representation of all the things that can harm your computer.

Yet, by studying this map, you’ll have a better understanding of just how enormous is the scope of personal computer security.

 

Who Is Responsible for Personal Computer Security?

Ultimately, you are. Of the nine specific threats outlined in the security mind map, only the Computer Vendor and the Operating System are beyond your control. Technically, your choice of vendor and OS can help or hurt your vulnerability! If we accept that vendors and software writers are fallible, then we must also accept the responsibility that comes with deciding to use their products and services.

When it comes to establishing and maintaining computer security, there is a huge difference between corporate/institutional computer systems and your personal computer. Corporate systems require trained staff to manage computer security. Even if you create images and backups, they’ll do you little good if, through lack of understanding, you practice unsafe computing habits that compromise your computer during daily use. Yet, it is unreasonable to expect you to know everything about managing your personal computer security. Therefore, it may be a good idea to create a short list of experts to which you can turn for advice on personal computer security.

Looking again at the security mind map, create a list of people and resources capable of helping you deal with each major threat area. There is some overlap between threats and in several cases, you may wish to focus on a more specific threat. Here’s how one list might look for a Windows PC user:

By learning from these eight expert resources, you minimize the impact of the ninth threat: Your lack of understanding. You also free up your time to educate yourself on general security issues. Here are a few good places to start:

Why Is Personal Computer Security So Difficult?

You have too many sources of expert advice. Some of these experts go overboard with their recommendations, making your computer experience less than enjoyable. For example, the excellent website, www.cert.org, suggests:


“9. Disable Java, JavaScript, and ActiveX if possible

Be aware of the risks involved in the use of ‘mobile code’ such as ActiveX, Java, and JavaScript. A malicious web developer may attach a script to something sent to a web site, such as a URL, an element in a form, or a database inquiry. Later, when the web site responds to you, the malicious script is transferred to your browser.”

A better suggestion is to use Firefox and install the NoScript extension from IT company Inform Action.

The complexity of the personal computer operating systems and software obscures potential security breaches. Tweaking your operating system or applications may enhance your overall computing experience. However, listening to bad advice or, worse, experimenting blindly, can lead to disaster. Mozillazine.org is a user-contributed wiki that contains an extensive collection of Firefox browser configuration changes. The configuration page is peppered with cautions and bug alerts.

Obscure Threats

Obscure to the average computer user, the following threats may never cross your path. Some of them are beyond your control. They are presented here just to ruin your day. :)

Peripherals attached directly to your computer or via a network connection may pose a threat to the confidentiality of your personal data.

In Windows Secrets Newsletter, Issue 224, 12/10/2009, columnist Dennis O’Reilly mentions two examples:

  1. Old fax machines that have been discarded retain recently received images on their carbon ribbons
  2. The Brother PT-2700 label maker has a dry ink tape that also retains a reversed image of everything that has been made with it.

In the fax machine article, the reporter concludes that printers with memory may also have a record of documents.

DNS cache poisoning has been the focus of much attention since being explained to affected computer companies in July, 2008 and to the public in August, 2008. It is a method by which hackers can spoof, or imitate, legitimate websites for nefarious purposes. Although many vendors have updated their software and instituted other defensive measures, US-CERT states that “routers, firewalls, and other gateway devices that perform NAT/PAT may modify source ports in ways that reduce the effectiveness of” the protective techniques.

9 thoughts on “How To Secure Your Personal PC”

  1. Have sent in a comment earlier but unsure if it gets through, thought I try again.

    All PC users are to be equipped with some basic security knowledge for own benefits. I agree with you that most of the time it’s about choices we made that will affect the outcome – vendors, OS, even the applications chosen. We may not be born experts but certainly can learn from our mistakes. :) Hacking, phishing, there’s nothing much to do but to be prepared. Well written.

    @wchingya
    Social/Blogging Tracker

  2. Thanks, Ching Ya! I may be harsh, but I’ve always blamed myself for security breaches.

    Back when the operating system was relatively simple (Win 3.1 and before), it was just a matter of learning from our mistakes, like you said. You could buy a decent book that explained how to manage your computer’s operating system.

    Today, there is just too much information :( .
    I’m less inclined to blame myself, since I know better than to click unknown links, install weird software or fool around with the registry (I literally hosed one system hacking the registry). Instead, I rail against makers of bloated software.

    My pet theme is “Let’s go back to the days of ROM-based operating systems.” I used to have a Commodore 64. If it crashed, a cold restart set everything right. ROM (read-only memory) was slow, but Commoore worked around that by “shadowing” it to the faster RAM. This also meant that we could experiment with the operating system!

    I miss those days.

    Cheers,

    Mitch

  3. Hi Mitch, I finally got to your site, but trust me my head has been spinning for the time I have been here. You have so much here I could be distracted for what…a LONG time. : D I read one article and I guess I better get some sleep, but it’s been fun. I added your site to my blog so I can get here quicker, and now…more often. Have a great week! R

    • Hi Rachel,

      I’m glad you will be visiting regularly. There is a lot here, spanning four years. (Five, if you count the stuff I republished from my first blog.)
      Some of it is outdated, other items are just plain boring. I hope you’ll check out my fiction and poetry, though. :)

      Cheers,

      Mitch

  4. Came here via your comment on my blog on the tinker, tailor article.

    Nice overview. Having just suffered some major security problems (which only went away finally with an XP-Win 7 upgrade), I am starting to pay a lot more attention.

    BTW, nice use of mind maps. You may want to check out trailmeme, a beta product I manage. Trails are related to mind maps (see the latest post on our blog)… they allow you to create mind maps through a set of links to web content basically.

    Email me if you’d like a beta invite, seems like you are a guy who’d find interesting uses for the technology :)

    Venkat

    • Hi Venkat!

      Thanks for visiting and leaving a kind comment on my blog post.
      Talk about serendipity! I was reading about substitution and income effects with my oatmeal and became thoroughly amused by the idea that people are so predictable that we could all be transistors in some alien’s Earth-sized computer. My son quickly reminded me that Douglas Adams explored this in Hitchhiker but, still…

      Then I see your comment here about Trailmeme! After digesting it as well as I could, I believe I understand what you mean by comparing it to mind-mapping at the crowdsourcing level.
      It is certainly a provocative technology – currently, the hyperlinking that defines the web lacks intrinsic cohesiveness. (That’s why Google makes daily fortunes providing context to web searches.) I believe that concepts like Trailmeme signal a paradigm shift in the organization and presentation of data.

      Without digressing too much, think about how XML reunifies data for an information consumer: once it was determined that HTML could never adequately separate presentation from the underlying data, we simply exposed the web to its own infrastructure. To data content producers, this may not be earth-shattering but, to content managers, XML and all of the specialized mark-up languages based upon it, represents unprecedented freedom.

      Back on topic, Trailmeme can enable serious content publishers to take more control in liberating the conent consumers from the haphazrd click-fest of the hyperlinked web.
      I can understand why you have potential copyright issues! Imagine being able to cobble together an entire treatise, simply by blazing a trail through the web! Who gets credit? The content publishers or the person who had the vision to link the ideas?

      I wrote a tongue-in-cheek essay about this very idea: Marxist Internet Propaganda.

      Thanks so much for sharing Trailmeme! I’ll be emailing you for that invite! ;)

      Cheers,

      Mitch

  5. Pingback: Tinker, Tailor, Coffee Maker? | Morpho Designs

  6. I use a good virus checker like ESET to protect my PC. Also a good firewall in place to stop direct attacks and outgoing trojens from stealing free ports. Also if you have WIFI set up then I would recommend at least WEP encryption and mac address filtering to keep the nasty internet thieves at bay. That about does me and never really suffer much with problems. Thats my 2c