US-CERT and CISA recently released a warning about a new tunneling malware application that the North Korean cyber operations group is using to move information from one computer to another, in order to exfiltrate that data. You can read about it at Malware Analysis Report (AR19-129A) MAR-10135536-21 – North Korean Tunneling Tool: ELECTRICFISH
“This report provides analysis of one malicious 32-bit Windows executable file. The malware implements a custom protocol that allows traffic to be tunneled between a source and a destination Internet Protocol (IP) address. The malware continuously attempts to reach out to the source and the designation system, which allows either side to initiate a tunneling session. The malware can be configured with a proxy server/port and proxy username and password. This feature allows connectivity to a system sitting inside of a proxy server, which allows the actor to bypass the compromised system’s required authentication to reach outside of the network.”
Detailed findings and incidents of compromise (IOCs) can be found on the US-CERT website.