by Charles Miller

On your computer, every computer whether Apple, Chromebook, Linux, Windows, etc., there is a small file hidden away that helps your computer know who and where it is. The file is somewhat of a vestigial organ in that it no longer functions as it did in its ancestral form, and that is a bit of an interesting story.

In 1984, long before the internet became "a thing" it did exist as a small network connecting a few universities, government, and military offices. At the time, the internet was so small that almost everyone connected to the network personally knew almost everyone else who was connected. It was a small club. Everyone's computer had a "hosts" file on it, and the "hosts" file contained a directory of the internet that was a list of everyone who was connected to the internet.

That system worked okay for a few dozen people, but by 1986 there were about 2,000 entries in the hosts file then the next year it ballooned to nearly 30,000. Soon there were millions of people who wanted to connect to the internet. Imagine if your smart phone contacts list had to include the names and numbers of all the millions of other people who have cell phones; that would never work. The engineers had to come up with a better solution, and they did. They abandoned using the hosts file.

The hosts file still exists, found on every computer; it just does not contain a list of everyone else's address any more. One important function it serves is to identify your computer and assign it a home IP address that is always 127.0.0.1. Any time any software wants to know where home is, it goes to the address 127.0.0.1 rather than looking on the internet. The hosts file can be used for ad-blocking by telling your computer not to even look for certain advertising that comes from the internet. If you add the names of advertising web sites to your hosts file, your computer will no longer be able to connect to those sites. There are lists of bad web sites available for doing this.

Using the hosts file in these ways has fallen out of favor, in part because of some antivirus software reporting the "PossibleHostsFileHijack" infection. This is usually a false-positive, but should not be ignored. Cybercriminals have been known to create fake web sites that are exact copies of Bank of America, Chase Bank, Charles Schwab, and many other financial institutions. The cybercriminals then try to find a way to steer unsuspecting customers to the fake web site in order to steal their username and password. One of the ways this has been done is for the crooks to modify the hosts file so that your computer connects to the fake bank site rather than your real bank's web site. If your antivirus software warns of "PossibleHostsFileHijack" please do not visit your bank's web site until you fix this.

Be careful if you tinker with the hosts file or your computer might forget how to find its way home. Just like Dorothy said in the 1939 film "The Wizard of Oz" "There's no place like 127.0.0.1", "there's no place like 127.0.0.1".

**************

Charles Miller is a freelance computer consultant with decades of IT experience and a Texan with a lifetime love for Mexico. The opinions expressed are his own. He may be contacted at 415-101-8528 or email FAQ8 (at) SMAguru.com.

Discover Lokkal:
Watch the two-minute video below.
Then, just below that, scroll down SMA's Community Wall.
Mission

Visit SMA's Social Network