ClickPDFSearch

ClickPDFSearch is a browser hijacker application that uses underhanded means to promote the address of a fake search engine - clickpdfsearch.com. In addition, it relies on equally as underhanded tactics to spread itself without users noticing its installation on their computer systems. This dubious behavior classifies ClickPDFSearch as a PUP (Potentially Unwanted Program).

Browser hijackers are equipped with the necessary programming to modify the settings of most popular Web browsers. ClickPDFSearch is not an exception, as it changes the homepage, new tab page, and the default search engine and sets all three to open the promoted address. 

Users should keep in mind that fake search engines cannot produce any results on their own, as they simply lack that functionality. Instead, they take the search queries and redirect them to another engine. More specifically, ClickPDFSearch redirects to either Yahoo, a legitimate engine or nearbyme.io. As you might have guessed, nearbyme.io is a dubious engine that produces untrustworthy results that might be promoting shady websites or include paid advertisements.

Most PUPs also are equipped with data-collection capabilities. They go after the user's browsing activities, track them, and then send the harvested information to a remote server. The targeted data could include the browsing and search histories, device details (IP address, geolocation, etc.), or in some cases, even sensitive payment and debit/credit card details.