Computer Info – May 10, 2000

This Week’s Program

        John Watkins will be hosting the meeting this week. His program will consist of looking at the new features of ACDsee version 3 -- a look at the new SpeedStep technology for laptops from Toshiba -- Mobile Computing using Cell-Phone and Infra Red connection ( look NO cables) -- and, of course, the normal ask a question !!!! session.
Internet Security
Information from Steve Gibson – Gibson Research Corporation -- http://grc.com
        If your computer is only connected to the Internet briefly, when you're browsing the web or retrieving and sending email, your connection exposure will be minimal. But if you are one of the millions of people who are discovering the amazing power and convenience of a persistent connection to the Net — through a cable modem or DSL line, then your exposure is substantially greater.
" The Internet is a BIG place. What's the chance that my little computer would even get noticed? "
        There are MANY FREELY AVAILABLE "scanners" being run by bad people who are sweeping the Internet looking SPECIFICALLY for computers running Windows File and Printer Sharing! They leave these scanner programs running night and day collecting IP addresses — one of them might be yours! — then they "map" that drive's shares onto their local drive letters to gain total access to your computer's files!
What can you do to protect yourself? The single BIGGEST security hole that exists is Windows File and Printer Sharing over your TCP/IP (Internet) connection. I've encountered many freely available scanners that specifically target "open Windows shares" and password crackers are free for the downloading.
        If your Internet-connected computer is not networked to any other machines there's absolutely no need to have file and printer sharing installed and often no need to have Microsoft networking loaded, running, consuming precious RAM memory, and dramatically lowering your Internet security!
Client for Microsoft Networks — Just Say No. The "Client for Microsoft Networks" is only used when connecting your Microsoft operating system to other Microsoft operating systems. It has NOTHING to do with the Internet All web browsing, email, newsgroups — everything — will continue to work just as it did before. It was unnecessarily installed and should be immediately removed. After you remove the Client for Microsoft Networks (and its related file and printer sharing) from all of your TCP/IP-using adapters, it quietly disappears from sight and your system's security skyrockets.
        You won't miss it at all, Windows will boot faster, and you'll have more memory for things you do need.
Removing Client for Microsoft Networks and file and print sharing. From MY COMPUTER – double click on CONTROL PANEL – then double click on NETWORK.
        To just disable the file and print sharing – click on the button labeled FILE & PRINT SHARING. Then check to see that there is no checkmark in front of "I want to be able to give others access to my files" and "I want to be able to allow others to print to my printer." Then click OK.
        To remove the Client for Microsoft Networks which will also remove the file and print sharing – highlight CLIENT FOR MICROSOFT NETWORKS and click the button labeled REMOVE. Then click on OK. You will be ask to restart your computer for the changes to take place.
All security problems will not be solved by the above methods. It is very important to note, however, that removing or disabling file sharing does not preclude the possibility of an intruder gaining access to your system through any of a number of other Internet services or systems that might be present in your computer. For example, numerous exploits have been documented of hackers entering a system through Microsoft's Personal Web Server, IRC, ICQ, telnet, web browsers, email readers, and anything else you can imagine! Therefore, if the security of your system is of true concern, you must act to proactively guard against intrusion. Any component within your system that touches the Internet creates a potential opening for attack.
        If your computer has a persistent connection to the Internet it will be quickly located, logged, and targeted as an opportunity for break-in by Windows share scanning intruders.
If you MUST share files across the Internet a personal firewall is the ONLY WAY to be safe!
        As we look at firewalls, a serious issue needs to be addressed: The frenzy to secure our Internet connected PC's has spawned a hoard of really bad pseudo-firewalls.
        If you are using a single stand-alone PC for Internet access, the preceding information will have equipped you to secure that machine without the need for any additional software. But if your needs are more complex, and especially if you do need to share files across the Internet, you will need some additional software to secure both ends of the Internet connection.
What's a Firewall? You can probably guess what a firewall does just from its name. The idea is a simple one, which is why it works so well: A firewall ABSOLUTELY ISOLATES your computer from the Internet using a "wall of code" that inspects each individual "packet" of data as it arrives at either side of the firewall — inbound to or outbound from your computer — to determine whether it should be allowed to pass or be blocked.
        A firewall is a super cool idea. This is so true, that someday firewalls will be standard equipment on all PC's. There's no question about it.
        All internet communication is accomplished by the exchange of individual "packets" of data. Each packet is transmitted by its source machine toward its destination machine. Packets are the fundamental unit of information flow across the Internet. Even through we refer to "connections" between computers, this "connection" is actually comprised of individual packets travelling between those two "connected" machines. Essentially, they "agree" that they're connected and each machine sends back "acknowledgement packets" to let the sending machine know that the data was received.
        In order to reach its destination — whether it's another computer two feet away or two continents distant — every Internet packet must contain a destination address and port number. And, so that the receiving computer knows who sent the packet, every packet must also contain the IP address and a port number of the originating machine. In other words, any packet travelling the net contains — first and foremost — its complete source and destination addresses. As we've seen earlier on this site, an IP address always identifies a single machine on the Internet and the port is associated with a particular service or conversation happening on the machine.
        Since the firewall software inspects each and every packet of data as it arrives at your computer — BEFORE it's seen by any other software running within your computer — the firewall has total veto power over your computer's receipt of anything from the Internet.
        A TCP/IP port is only "open" on your computer if the first arriving packet which requests the establishment of a connection is answered by your computer. If the arriving packet is simply ignored, that port of your computer will effectively disappear from the Internet. No one and nothing can connect to it!
        But the real power of a firewall is derived from it's ability to be selective about what it lets through and what it blocks. Since every arriving packet must contain the correct IP address of the sender's machine, (in order for the receiver to send back a receipt acknowledgment) the firewall can be selective about which packets are admitted and which are dropped. It can "filter" the arriving packets based upon any combination of the originating machine's IP address and port and the destination machine's IP address and port.

One recommended firewall program
        ZoneAlarm 2.0 (a firewall program) has been released! My fingers are crossed, the dust is still settling and the paint is still wet. It's too early to tell for sure, but it looks like Zone Alarm 2.0 (ZA) will be the PERFECT and ULTIMATE PERSONAL FIREWALL for the typical Internet user! And it's 100% free for the individual user! I am using it right now — and NOTHING ELSE! — on my personal system, and so far I love it! I think ZA combines the best of ALL worlds and eclipses every other firewall ever created.
                  http://www.zonealarm.com