Usually unwanted software and malware finds it’s way to a user’s computer from infected web links, flash drives or during an installation of popular programs. Most types of malware are designed to hijack browser search and inject ad popups and to install doorways and other malicious software. Some malware programs can also reveal your sensitive private data to hackers and result in ID theft, Credit Card fraud.
It is highly recommended not to install unknown software and use Anti-Malware software to protect your computer from hijacking. In case your computer got infected, it is highly recommended to perform a PC scan with Anti-Malware software in order to remove all the threats before any backdoors might be installed.