I don't think that the traffic can be removed, but it can be filtered out using segments and a virtual report suite. How accurate the segments are depends on your implementation, since excluding all visits from South Korea may not be as ideal as excluding visits from particular IP addresses (you'd need to be capturing the IP address in a variable, as this isn't an out-of-the-box option).
If you haven't created a virtual report suite already, you can get some decent information at https://docs.adobe.com/content/help/en/analytics/components/virtual-report-suites/vrs-about.html.