Researchers have found that if a website is configured in a certain way, an attacker can abuse a Dell self-signed certificate that comes installed on your Dell machines to extract a device-identifying code (Service Tag). This code could be useful information for carrying out tech support scams against your users.
The certificate is not malware or adware. Rather, it was intended to provide the system service tag to Dell online support allowing them to quickly identify the computer model.
Here is a link to the uninstaller that will remove this certificate.