Enter the flag:
Claim Command:
/challenge claim flag:<flag>
Pwn windows box with EternalBlue (Flag is on the desktop of the LUHack user)
Boxes: win-infra-<0..n>
Make sure you use a bind shell, windows/x64/meterpreter/bind_tcp works well.
If this doesn't work, try one of the other win-blue machines. EternalBlue likes to trigger BSODs.