PC101-Personal Computer 101

What are viruses and why do they even exist?!

Viruses can make yourcomputer go crazy!!!!

You know that is a very good question!  Viruses are self-contained programs that get onto your system with the intent of damaging your PC and/or propagating to other PC's to do the same.   They get on your system in a variety of ways:  via email (via active links and attachments), downloaded files, any removable media like CD's, DVD's, floppies, through programs on your computer that access the internet and sometimes just because you are on the internet and happen to be vulnerable.

You are most vulnerable when connected to the internet.  And don't think you're OK if you have DSL or cable internet.  You actually can be more likely to be attacked as you are essentially connected 24 hours a day.  A friend who has DSL used network monitoring software to record any unauthorized attempts to access his computer, and he recorded over 100 per hour!

Generally, you need to be very wary of emails from people you do not already know, and remember, hackers can substitute the "Reply" email address with another one to try and fool you (e.g. your name and email address as "Sender").  Unless you know the Sender, do not click on any active links or attachments that come in emails you cannot confirm the Senders identity.  I know this is a pain, but much better than getting a virus.  Hackers sometimes pretend to be your ISP, Bank, Credit Card company to either install viruses on your system, or trick you into providing personal financial information that they can use to rob you.   As an example, here is the text from an email I got, supposedly from my ISP, telling me I have a virus and to run the attached .zip file to fix the problem:

Dear user of isp.com, mail system administrator of isp.com would like to let you know the following:

We have detected that your account has been used to send a huge amount of junk email messages during the last week.
Most likely your computer was infected and now runs a hidden proxy server.

We recommend that you follow our instruction in the attached file in order to keep your computer safe.

Best regards,
isp.com user support team.

I noticed that the Reply address was not from my ISP (but they could have faked that) and I do not trust attached files, so I ran my antivirus program on the attachment and it had two copies of the new "Doom" virus within it!   I deleted the email and then emptied my email Trash folder, and to be sure ran my antivirus program on my whole disk.

WHY do viruses exist?!   Well that's a tough one to answer, as you would need to understand the thought process of a typical hacker who creates such programs to destroy and damage other computers.  Possible reasons are:  the challenge, the notoriety with other hackers, the potential negative publicity, and for the "fun" of it.   Obviously, those with too much time and too little common sense.

Unfortunately in this day and age, every PC needs to have a good (1) anti-virus program running (and updated) at all times and (2) preferably a Fire Wall.  Windows XP comes with a Fire Wall and although it is not a very aggressive one (checks Incoming access only), it is better than nothing -- so turn it on (see How do I turn on the Windows XP Fire Wall?)

There are lots of Anti-Virus programs out there for purchase and for free.  Generally the store-bought ones have a limited time where you get the updates on new viruses for free, then you have to pay a yearly fee.  The free (shareware) ones have updates for free also, but the tradeoff is the free ones generally are not as good, but there are exceptions.  For example, I have found that the Avast! anti-virus program by ALWIL software is better than some store bought ones.  I say that because:  (1) It is easy to download and install (2) The default configuration is mostly where you want it (3) It automatically updates both the program and new virus updates (4) It has an optional "backup" program (called VRDB) that keeps copies of your uninfected system files for you in case a virus does break through the protection and damage your system files (5) And this is one of the rare occurrences where you actually get an answer to support questions from the company!

Get yourself a program of your choice and make sure it is running anytime you are on the internet or using portable media.  Antivirus programs are normally composed of two components:

I suggest getting a Fire Wall as another line of protection.  Fire Walls attempt to prevent viruses from ever getting on your system in the first place.   They are more complicated to use and do eat-up their share of system resources so they can make your system noticeably s..l..o..w..e..r.   But if configured correctly you can minimize that impact and a slow system is better than a corrupted or destroyed one!  Windows XP® comes with a firewall, but it is turned off by default.   Click here for info on how to use it.  NOTE:  The SP2 version of XP® has the firewall ON by default.

Spyware and Adware

Finally, there are many terms thrown around describing viruses, including trojan horses, worms, bugs, adware and spyware.   Let's just say that they almost all impact your system to some degree and should be removed if possible.   Adware and Spyware generally does not intend to cripple or destroy your system but to monitor your internet choices and report them, use your system resources without your permission for other purposes or simply track what you have on your system and if you use it.   Again there are many programs out there that deal with these and you can buy them or get them free.  I run two different  ones myself, as each one has its own strengths and weaknesses (SpyBot® by Patrick Kolla and Ad-aware® by Lavasoft®, Sweden).
Bugs in yourcomputer!

Final word on today's world:  unfortunately, the world today is not as many of us grew up knowing, and no matter how good you think you are at uncovering scammers, some are better than you.  That is because they dedicate their life to fooling you and getting your money, and if you do not do "your homework" and not assume anything, they will get you.  A new popular scam is called "Phishing" where a hacker may pretend to be your bank, credit card company, utility or other organization that has personal information on you.  They may attempt to get you to divulge personal information that they can then use to drain your accounts or steal your identity.   

TIP:  Spyware and Adware, as well as some viruses, get on your system from you downloading files and programs, opening attachments to email from unknowns and is added to some packaged commercial software media.  You can reduce the change of getting any of this unwanted stuff by not opening attachments or links from unknown email sources, restricting the downloading of programs from the internet to those you really need, and regularly running AntiVirus and Anti-spyware SW.   For a complete list of common sense prevention's, see this list.

Got questions you would like answered?  Yes

keoni@isp.com