I use Sandboxie to sandbox some of my applications, like Web browser. Sandboxie has an option to use a secure deletion tool to wipe all files in sandbox when they are deleted (e.g. when web browser is closed). However, this feature has now been removed, because some files can be deleted by other means, or before web browser closes, so it gives a false sense of security.
I use Sandboxie in combination with RAMDisk, to place the sandbox onto the RAM disk, and although RAMdisk has an option to wipe the RAM disk memory when dismounted, it doesn't have an option to intercept delete commands for files on the RAM disk.
Would it be possible for RAMDisk to intercept DeleteFile() API calls (and any other relevant calls) and overwrite/wipe the memory used by the files?
Also, can you add a feature (i.e. menu item/toolbar button) to manually initiate a wipe of one (or more) selected RAM disks, without the need to dismount them first?
A RAM disk is a simple block storage residing in memory. It does not have the concept of files or file systems as those are of a higher-level abstraction in the OS. So it's not possible to wipe the memory holding deleted files.
Moreover, such wiping is unnecessary as all memory contents completely disappear on reboot, shutdown or power loss. But if you still want to securely wipe free space on a RAM disk, you can use a tool called sdelete from Microsoft, or the built-in command
where X is the drive letter. You could run it on demand with a shortcut, or from Windows Scheduler, and wipe the free space periodically.