https://www.theregister.co.uk/2017/09/28/high_sierra_hijinks_continue_nasty_apps_can_pull_your_passwords/ >A security shortcoming in earlier versions of OS X has made its way into macOS High Sierra despite an expert's best efforts to highlight the flaw. >Patrick Wardle, of infosec biz Synack, found that unsigned, and therefore untrustworthy, applications running on High Sierra, aka macOS 10.13, were able to quietly access sensitive information – including stored passwords and keys – without any notification to the user. Normally, apps, even signed trusted ones, trigger a prompt to appear on screen when touching the operating system's Keychain database of saved passphrases and other secrets.