I would say it's undetected, it's just they don't care for now.
If you check the dmp files from a crash you will see that the dll is clearly detected as loaded and as a hook.
ex E:\Steam\steamapps\USERNAME\PAYDAY 2\iphlpapi.dll E:\Games\Payday 2\Trainers\Lua Injection\iphlpapi Hook\Release\iphlpapi.pdb
try out yours at dumps.metastruct.uk.to