Sounds like you picked up a dose of Malware. See this support article: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

In addition to the above : Both mapseasy.net and 'searchsafe' are broswer hijjackers and, like <BR>'the-edmeister' indicated, malware. Go to the Firefox menu (≡) => Add-ons => Extensions ( Mac : Command + Shift + A) and look for '''any other unfamiliar or suspicious looking extensions'''. When you find any : remove them. Do the same here : for Windows => Control Panel for Mac and Linux => System Preferences However : most malware will be 'hiding' somewhere , so let's run malware scans, hence you should run the malware scans that are listed in the article 'the-edmeister' gave you a link to. '''Run most or all of the listed malware scanners'''. They all work differently - what one program doesn't pick up, the other might. Also see : https://www.pcrisk.com/removal-guides/11152-mapseasy-net-redirect And : https://www.pcrisk.com/removal-guides/9096-searchsafe-com-redirect