What is a practical tool or script for creating hidden registry entries for persistence?

For PowerShell, you can use Brian Reitz’s project (linked in the article) that leverages PSReflect to call Native API functions. It creates a hidden value named `\0abcd` under `HKCU\Software\Microsoft\Windows\CurrentVersion\Run` with content like `mshta javascript:...`. This method achieves persistence that evades standard registry inspection. See the Study Notes of WMI Persistence using wmic.exe for another persistence technique.