The wiper function is activated via the command-line parameter '/WIPEMODE' with key-based authentication. When activated, the wiper deletes all file contents and reduces files to 0 KB, but the file names and folder structures remain intact. Victims can still see their files, but the contents are permanently lost.
Before we start, we just want to make sure those files are actually permanently deleted. We've seen plenty of cases where files weren't gone at all - they were just hidden.