Firefox.exe attempts to export my credit card details. How do I stop it.

Please consider turning on send info to Mozilla before posting a question. This helps us help you. As I have no info from your system that would help see things that cause issues. Would have shown me all your Extensions. So to have credit card details I would think that it is entered in a Extension. Copy/paste about:addons then click Extensions and go to the gear icon right page top and click update. If this Extension is Legacy I would delete your info then uninstall/remove it as Firefox 57 Quantum release date is Nov 14th. https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed. Run more than 1 scanner as diff tech in each : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware Keep your Reports and google each one so do not delete something you want to keep. If need help : https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/ Please let us know if this solved your issue or if need further assistance.