I am not a security expert, but until you get a more detailed answer from someone else, please make sure you have a good antivirus program (like Microsoft Security Essentials http://windows.microsoft.com/en-us/windows/security-essentials-download) installed. Out of curiosity, do you know the URL for the Amtrack website you were on?

It looks like you wanted amtrak, not amtrack.

You should never respond to such a pop-up to update a program, but always go to its own website to get the latest updates.<br /> If you respond to such a pop-up on a web page then this may always be an effort to infect you with malware. ----- Do a malware check with some malware scanning programs on the Windows computer.<br> Please scan with all programs because each program detects different malware. Make sure that you update each program to get the latest version of their databases before doing a scan. *Malwarebytes' Anti-Malware:<br>http://www.malwarebytes.org/mbam.php *SuperAntispyware:<br>http://www.superantispyware.com/ *Microsoft Safety Scanner:<br>http://www.microsoft.com/security/scanner/en-us/default.aspx *Windows Defender: Home Page:<br>http://www.microsoft.com/windows/products/winfamily/defender/default.mspx *Spybot Search & Destroy:<br>http://www.safer-networking.org/en/index.html *AdwCleaner:<br>http://www.bleepingcomputer.com/download/adwcleaner/<br>http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml *Kasperky Free Security Scan:<br>http://www.kaspersky.com/security-scan You can also do a check for a rootkit infection with TDSSKiller. *Anti-rootkit utility TDSSKiller:<br>http://support.kaspersky.com/5350?el=88446 See also: *"Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

This a earlier upload I did of of same file. https://www.virustotal.com/en/file/6b4ad5d27c24539fb5577b38f56b49cdbe1caa247184752193b45a6fa5ecc14a/analysis/1371096292/ Detection ratio: 12 / 47 The tiny file size should have been a big clue in that it was not a full Firefox setup download from Mozilla.org