Thanks for the link SIR****TMG.
I just looked at the code to see how it works and like the website says it's based on the eye chart but it uses CSS instead of images.
When the page loads it tries to load CSS style-sheets in different sub-directories
Code:
<link rel="stylesheet" type="text/css" href="http://four.cs.uni-bonn.de/fileadmin/user_upload/werner/cfdetector/d.css" />
<link rel="stylesheet" type="text/css" href="http://iv.cs.uni-bonn.de/fileadmin/user_upload/werner/cfdetector/c.css" />
<link rel="stylesheet" type="text/css" href="http://downad.four.cs.uni-bonn.de/fileadmin/user_upload/werner/cfdetector/b.css" />
<link rel="stylesheet" type="text/css" href="http://defender.four.cs.uni-bonn.de/fileadmin/user_upload/werner/cfdetector/clean.css" />
It works where if the bottom one (
the all clean style-sheet) is blocked then you'll get an infected image....different images for different versions.
it loads different <div>'s depending on the style-sheets.
Code:
<div class="infected-d"><img src="infected.png" alt="infected" class="status" /> Status: <font class="status">System is possibly infected with Conficker.D</font></div>
<div class="infected-c"><img src="infected.png" alt="infected" class="status" /> Status: <font class="status">System is possibly infected with Conficker.C</font></div>
<div class="infected-b"><img src="infected.png" alt="infected" class="status" /> Status: <font class="status">System is possibly infected with Conficker.B</font></div>
<div class="clean"><img src="clean.png" alt="clean" class="status" /> Status: <font class="status">There are no signs for an infection.</font></div>
I guess it works because conficker is blocking sites with defender in the url?...and other versions of conficker blocking the other sub-directories is how it can tell what version you have.
I tested it by blocking the all-clean style-sheet url and I got an image saying I was infected with Conficker.B.
@Blackmirror
That's how it works though I'm not sure how reliable it is without actually being infected with conficker.
