You have a tracking cookie in your system. You can thank Quantserve.com for it.
It's not considered malicious therefore not considered a threat, so your anti-virus won't pick it up.
It's not malware but rather adware.
I'd recommend you look for a removal tool online - there appear to be a number available.
Below is how you can try to block it, but by doing so it may act erratically as it can't access it's server. Better to remove it.
To learn more about it, go here
http://shareknowledge123.blogspot.ca...-tracking.html
From
http://shareknowledge123.blogspot.ca...-tracking.html
quantserve.com Removal Instructions:
Go to Start > Settings > Control Panel > Internet Options.
Click the Privacy tab, click the Website button or Edit button in Website group box.
In the Website box, enter quantserve.com and click Reject button to add this website to block lists.
Click Ok button to save the changes.
Open the file "%WinDir%\system32\drivers\etc\hosts" with a text editor program.
Add the following lines to the end of the text file.
127.0.0.1 quantserve.com
www.quantserve.com
127.0.0.1 edge.quantserve.com
127.0.0.1 pixel.quantserve.com
127.0.0.1 quantcast.com
www.quantcast.com
Save and close the file.
Reboot your computer.
From
http://www.exterminate-it.com/malped...quantserve-com
To block quantserve.com cookie in Google Chrome
From the Chrome menu Google Chrome Menu Button, on the browser toolbar, choose Settings
Click Show Advanced Settings... link
In the Privacy section, click the Content settings
Click Manage Exceptions... button
Enter quantserve.com in the Hostname pattern (located at the left corner)
Choose Block from the Behavior field (on the right)