Formatting versus wiping

Completely Clueless · 11-19-2009, 06:59 AM

HI all,

When you go through an install procedure and you get to the part that says, "are you sure you want to format this partition; all data will be destroyed!"
It's not technically true, is it? I mean, formatting doesn't wipe all the data on a partition in the same way that over-writing it with zeros using 'dd' for example would do, does it?
Is it possible that re-formatting alone could still leave some malware behind on an infected partition?

thanks.

Komakino · 11-19-2009, 07:04 AM

Sort of, apart from the malware part. The contents of the data is there, but there is no way to access it directly so there's no way for the malware to run.

pixellany · 11-19-2009, 07:07 AM

"formatting" I think typically means only to install the filesystem. You are correct that it does not destroy all data, but --from the users perspective-- all access to that data is lost.

"malware"--like any other SW--has to be somehow "connected" to the rest of the system---ie a piece of executable code left behind after formatting cannot just magically start running, since nothing in the OS or other SW has a way to call it.

Completely Clueless · 11-19-2009, 08:43 AM

Okay, thanks guys. That's as I thought. The only point of wiping therefore is if you might have some credit card numbers or other secure ascii data lying around on a disk; they can still be read, but programs can't be run.

pixellany · 11-19-2009, 08:55 AM

Correct--the data (and the malware) can still be read---but only using raw device access. For example, recovery SW such as photorec or testdisk uses raw device access.