Migrate post/windows/manage /persistence_exe to an Exploit

[smcintyre-r7]

The existing post/windows/manage/persistence_exe module should be migrated to a local exploit, most likely exploit/windows/local/persistence_exe. The existing STARTUP datastore option should become an action.

The user should retain the ability to specify their own executable file to be used.

The module should also replace the existing exploit/windows/local/persistence_service module since they both support a scheduled task as the means for execution.

The module should also replace the existing exploit/windows/local/persistence which executes via the registry startup.

[ArkaprabhaChakraborty]

I would like to take this up