Panic-Heroine
My internet was quite fine and had no pop-ups before the block, xD.
That's because it's not normal. It's something only hackers take advantage of.
The hackers are abusing something called
basic access authentication.
Take this example.
You're browsing the Gaia forums. You come to a thread that looks interesting. You click the link to the thread. Your computer and Gaia's servers perform some HTTP exchanges, and you recieve the HTML for the page.
One of the images on the page is stored at http://www.example.com/images/evil.jpg, so your browser sends an HTTP request to example.com.
GET /images/evil.jpg HTTP/1.0
Host: localhost
However, example.com requires aurthorization, so it sends you a 401 message.
HTTP/1.0 401 UNAUTHORIZED
Server: HTTPd/1.0
Date: Sat, 27 Nov 2004 10:18:15 GMT
WWW-Authenticate: Basic realm="Secure Area"
Content-Type: text/html
Content-Length: 311
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/1999/REC-html401-19991224/loose.dtd">
&HTML&
&HEAD&
&TITLE&Error&/TITLE&
&META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"&
&/HEAD&
&BODY&<H1>401 Unauthorized.</H1>&/BODY&
&/HTML&
When your browser recieves this, it will pop up a dialog box asking for your user name and password so the server can authenticate you.
Since you are still looking at a Gaia forum page, you decide it's safe to provide that information. You type in your user name as "Aladdin" and your password as "open sesame". (If that really is your password, please change it now.)
Your computer sends this:
GET /images/evil.jpg HTTP/1.0
Host: localhost
Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
Note that the password is not actually encrypted. Your user name and password have been combined and is sent as a Base64 number.
Upon recieving that, and verifiying that you are who you say you are, the server at example.com sends the desired image. (Exept in this example it didn't actually test your user name and password. It stole it and authenticated you anyway)
HTTP/1.0 200 OK Server: HTTPd/1.0 Date: Sat, 27 Nov 2004 10:19:07 GMT Content-Type: image/jpeg Content-Length: 10476
And then sends you the image that you unknowingly requested.
