Smilebox Toolbar is an add on or call it an extension for a browser such as Google Chrome, Safari, Internet Explorer and such. Although it is not illegitimate, but due to its similarities with applications used in phishing by hackers such as spyware, malware etc, it is also considered malignant and untrusted. In terms of installation, it can be installed voluntarily by a user himself or a third party application, freeware, phishing email, spyware may be the primary cause to bring it into the browser.
Sometimes, Smilebox Toolbar is found to bring in malignant toolbars, spyware and other malicious apps in the system, also it collects data such as cookies from the browser to determine what users are surfing. It is this property of digging out information and privacy exploitation that has made it a great use to hackers and cyber criminals when it comes to extracting information such as banking details and such of a user.