Internet and computer security
If you start experimenting on your computer, you'll soon notice a few strange and funny things. There's a lot possible, if you go a step further than clicking on icons. My Windows tips & tricks page shows a few hints.
See my Dos-commands page for some interesting details. On networks and the internet, you end up in the subject security automatically this way.
PowerBASIC (very fast compiler for DOS, easy to learn), inline assembly (not that easy, but fast and powerful), and Delphi (Windows-programming).
I don't program intensively; it's rather a hobby for me. But it's a good way to learn about computers.
Example of my programs:
Knip - to cut a big file in pieces (floppy size), and put the pieces back together. Freeware!
It's more than visiting or designing web pages, email, and news. Try "Telnet ". Telnet is about the command-line-interpreter for networks. Compare it with executing DOS commands on a Windows PC. About everything you can do with your browser or mail program, you can do with telnet too, as long as it's a TCP-connection. You don't really need telnet in normal circumstances, but you can learn a lot from it. "Telnet" to your own mail server, port 25, and try the commands. "Help" is one of these commands. Before you know it, you can send "fake" email. Though I don't want anyone to break the law - if you start experimenting, you're on you own, and responsible for what you do.
Everyone has a confidential document on the PC, even temporarily. Did you know that there are a lot of circumstances where others - by network or internet - can see files on your computer, even change or delete files? Beware if you leave JAVA active in your browser, (by default it is active after installation of MSIE), or if you use older browsers. Also, be careful if you download executable files, even more if someone sends you the file. There are programs like Back Orifice and NetBus, able to install themselves quasi invisible. These programs take over your whole system. The name of the executable can be anything, but beware if the size of the executable is about 124928 bytes (Back Orifice) or 472576 bytes (Netbus). The extentions *.exe, *.com, *.dll, *.bat, *.scr , *.ocx, (list not complete) are all executable. If you noticed after a few weeks that every keystroke has been intercepted and sent..... you wouldn't feel happy. Fortunately, recent virus scanners can recognize these "trojans".
If you trust simple stuff like BIOS passwords, there are lists (on the internet - try a search engine) of general passwords, that open about every BIOS. Try the passwords "j262" or "589589" (without the quotes) on a PC with AWARD BIOS, version 4.5x. If you trust password encryption of word processors or spreadsheets, there are a few tools available able to unprotect the file or show the password - in a second or so.
About every month (or couple of months; it's not possible to predict when security holes will be found :-), I send a general mail about computers security (general message in Dutch - details in English). Normally I restrict the subject to issues that are important for home users. Just send me a message if you'd like to receive this general mail. I gather my information on several security / hacker sites or mailing lists.
