Strange bug after running CCleaner free space wipe?

[Robbie]

I have noticed one bizarre bug which occurs after running the free space wipe with CCleaner - it caused some sort of strange behaviour if used alongside the free space wipe in Eraser and then the Deep Scan in Recuva is run.

 

Simply Eraser works by creating a number of largish temporary files which fills free space and then at the end of the process the temporary files are overwritten and deleted. The result is a large number of 0kb files that can be seen by running Recuva. Now, if the free space wipe is run with CCleaner and then at some point this Eraser free space wipe is run then on an initial run of Recuva (with the Deep Scan option NOT checked) the run will reveal that there are X amount of zero byte size files (as should be expected - this is normal behaviour of how Eraser works). Now run a scan with Deep Scan checked and the scan will reveal those same files PLUS the same files also showing as temp files (ie from a different directory) which doubles the amount of 0kb files found AND a number of Eraser files with a 42MB size are also found - these show as being in the same directory as those additional 0kb temp files and all contain data from what I can see, presumably the data that Eraser writes to each file as the program works its way through the free space. The files are all shown as being "excellent" for recovery with the green symbol showing. To compound the mystery of this, if I then run chkdsk on the volume with the /f parameter then all those additional files disappear if I run Recuva again - the only files then showing are the ones that would have shown had I never run the free space wipe with CCleaner. The problem then returns the next time I run a free space wipe with Eraser.

 

I tried this on all volumes on my XP computer and this strange behaviour happened each and every time. On my Vista laptop the amount of 0kb files doubled but the 42MB Eraser files never appeared. Again running chkdsk (volume) /f cleared the problem. The MFT also seemed quite large after running the free space wipe with CCleaner on each and every volume on both XP and Vista, much bigger than it had been before on a couple of volumes.

 

Quite what this behaviour is and why it happens is beyond my understanding, but it is weird. It seems to be the interaction of CCleaner and Eraser free space wipes that is causing it - it had never happened until I ran the CCleaner free space wipe feature. I also hope I've explained it clearly - I know what I mean to say but explaining it isn't straightforward!