Archive: Business & Technology

Dr. Digit 'Splains It All

There are two kinds of computer file, executable programs and data files.  Data is just stuff.  A book report, a picture of Aunt Nellie, your budget for the year or whatever.  Executable Programs do things.  Your word processor is one, as is your picture editor, your web browser, your iTunes software and so on.  Let's say a little program that says "I there" attaches itself to your word processor.  Whenever you want to write a program you start the word processor and it says "Hi there" to you.  You think, "how nice, it likes me!"

Well, maybe.  Maybe not.  Computer viruses are little programs that duplicate themselves just as biological viruses do.  They infect other programs so that when you run them you also run the virus.  If it's a malicious virus it can cause irreparable damage to your computer, delete your files, and generally make your life miserable.

Viruses duplicate themselves by definition, and they tend to hide in other programs and under false names.  The most common way to get one is to click on a file e-mailed to you.  That runs the program that duplicates itself, attaching itself to other programs which will do the same thing when you run them after they are infected.

Programs have "EXE Headers" a little section of computer code that tells the computer where things are in the program so it can run it.  Virus writers re-engineer the EXE Header so that it tells the computer to run the virus in addition to or instead of the program.  Then they attach the actual virus code, hiding it within the rewritten program code.

Who writes computer viruses?  Pimply weasel-faced nerds who have nothing better to do than make other people miserable and puff up their misguided sense that they are smarter than everyone else.  Well, that's what we'd like to think.  The fact is that we don't know who wrote them unless they happen to be caught by law enforcement agencies.  These miserable souls have cost individuals and businesses millions of dollars and have caused a whole Anti-Virus industry to spring up which includes over the counter anti-virus programs, and expensive expert virus removal services.

Viruses used to be spread by sharing floppy disks.  Now that floppies are no longer common e-mail has become the carrier of choice.  If you get an "attachment" in your e-mail never click on it unless you are 100% sure of its pedigree.  Virus writers count on you having a trusting soul, or at least enough curiosity to click on those files.  Windows users are most at risk, almost certainly because it has the largest pool of victims.  You will rarely (but never say never) see viruses on a Mac or a Unix system.  The best defense is a strong offense, which means get a good Anti-virus program and turn on the automatic updates, and be careful.  

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