Clear sensitive information from vdi

I'm able to obtain file names and their contents from vdi image using grep despite the files were deleted. Example output:

MICROS~3.DLLans0��1FR�b��?,|�R��?,|�R��?,|�R�� !Microsoft.Transactions.Bridge.dll�H^@�x�x�1_��9�����yFILE0��m8��`HFR�b��FR�b��o�}�R��o�}�R�� �0xZ1FR�b��o�}�R��o�}�R��o�}�R��

When I mount the vdi image using vdfuse, grep can't find the same information. I've also tried wiping free space with sdelete, but without effect. How could I remove this information?

Update: Example output with email:

file.ext.LCK0xZ��0̮=T��0̮=T��0̮=T��0̮=T�� 
                                                                      FILEEX~1.LCK�X<NAMENAMENAME__aaaaaaaaa@aaaa.aaa.aa�����yGFILE0��l8��`H�y���y��v�R��v�R�� �0xZ1�y��O�t�R��O�t�R��O�t�R��

Im ieee

Posted 2015-05-18T10:22:50.967

Reputation: 101

You want some sort of free space sanitation utility. Note that such is normally distinct from rewriting unused parts of the file system. This is unrelated to VirtualBox. Keep in mind that outright software recommendation questions are off-topic on Super User. – a CVn – 2015-05-18T11:09:56.323

It's just an example. There are also deleted files with emails and names. And does sdelete do the same task? – Im ieee – 2015-05-18T10:39:55.930

sdelete -z C: promises to zero out unused space on the drive. Also promises to optimize virtual disk usage, but I have no idea how virtualbox decides what parts of disk can be made sparse. https://technet.microsoft.com/en-us/sysinternals/bb897443.aspx – wigy – 2015-05-18T10:45:37.530

I'm using it with -c flag. I've added an example with email to the question. – Im ieee – 2015-05-18T10:58:31.010

Clear sensitive information from vdi

Answers