Nationzoom is a browser hijacker that modifies browsers to use its search engine and display ads. It spreads through various methods like social media and infected websites. The document provides steps to identify if a system is infected by Nationzoom changing the homepage, causing slow browsing, and showing filtered search results. It warns that infected browsers will have authentic search results blocked and users redirected to other sites. The hijacker can be difficult to remove as it modifies browser settings and files. The document provides instructions to change browser shortcut properties and settings to remove Nationzoom and recommends using malware removal software to fully clean the system.