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Author Topic: How should I sanitize a secondhand computer  (Read 3476 times)

Offline syhprum

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How should I sanitize a secondhand computer
« on: 01/09/2012 12:50:56 »
After a reforming mishap I loaded EASEUE to try and salvage some destroyed files, I turned up little that I wanted but turned up some (Inoxious) videos that I did not know existed.
If I bought a second hand computer I would worry that the drives could contain materiel that could cause my imprisonment which I could not find but more hi tech forensic examiners might find if I fell foul of the law.
What should I do, is there any sure fire way of cleansing the the drives or should I replace them and destroy the old ones which might well negate the economic advantage of buying the computer.   


 

Offline CliffordK

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Re: How should I sanitize a secondhand computer
« Reply #1 on: 01/09/2012 13:13:48 »
If you are reformatting the drive, then look for some "wipedisk" programs, and set them to run with putting multiple random patterns on the drive.

If not reformatting the drive, you can look for some freespace shredders.
 

Offline RD

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Re: How should I sanitize a secondhand computer
« Reply #2 on: 01/09/2012 23:10:23 »
You could use a live CD (DVD/USB) system like DBAN (it's free) to wipe (overwrite) all the data on the computer's hard drive, otherwise if you rely on a program running on the computer's OS to wipe all of the data on the computer's hard drive it could wipe something which stops the OS from working before cleaning the previous users data is complete.

NB: DBAN will wipe everything from the computer's hard disk, including the operating system. If you are not in a position to reinstall the operating system don't use it on the computer.

Overwriting an entire hard-drive with random data can take hours. If you have windows OS running on the computer you could try running Recuva (also free) which will show any deleted but recoverable data left behind by the previous owner. Recuva can be instructed to securely overwrite any file it finds (one overwrite is enough).  If  Recuva draws a blank I think overwriting the whole drive with something like DBAN is probably a waste of time.

https://www.google.co.uk/search?q=live+cd+wipe+hard+drive
« Last Edit: 01/09/2012 23:57:47 by RD »
 

Offline CliffordK

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Re: How should I sanitize a secondhand computer
« Reply #3 on: 02/09/2012 04:54:55 »
The version of wipedisk I've used in the past was made by John Stanish.  Unfortunately it looks like the original distribution website is down.  It was a pretty simple program.  One would boot to DOS, and then start the shredding with a DOS command, with command line parameters.  It was pretty slow for smaller hard drives.  I'd hat to imagine  wiping/shredding a terabyte drive.

Of course, a good Degausser is effective with wiping the hard drives.  But, it is hard on the hard drives (i.e.  probably no longer functioning).  I think it was generally OK for wiping tapes of all sorts, but I had troubles reformatting some floppy disks after degaussing.
 

Offline neilep

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Re: How should I sanitize a secondhand computer
« Reply #4 on: 02/09/2012 05:47:45 »
There ewe are.




Glad I could help !
 

Offline syhprum

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Re: How should I sanitize a secondhand computer
« Reply #5 on: 02/09/2012 21:39:04 »
After de Gaussing would you not have to restore the partition structure before reformatting ? 
 

Offline chris

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Re: How should I sanitize a secondhand computer
« Reply #6 on: 02/09/2012 21:58:50 »
ccleaner (previously "crap cleaner") has a drive free-space wiper which will do a range of different passes to overwrite and sterilise drives. I trust this software; it downloads without installing 50 million toolbars and other bits of spam and has worked acceptably for me; that said, I've never given my disk to a forensic recovery service to work on before, so I cannot say whether it will completely remove was it alleges to remove...
 

Offline RD

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Re: How should I sanitize a secondhand computer
« Reply #7 on: 03/09/2012 03:13:07 »
After de Gaussing would you not have to restore the partition structure before reformatting ? 

If you could degauss the hard drive it would render it unusable : it would erase the reference tracks on the disc which are used to position the read-write head, (not fixable by user).

One overwrite is enough to make the old data unreadable ... https://en.wikipedia.org/wiki/Data_remanence#Feasibility_of_recovering_overwritten_data

If you were using software running on the computer to clean the computer (like the free Piriform programs mentioned in this thread) the only thing you should worry about is a hidden partition which they won't see (and won't clean).  That's where a program running on a live-CD has an advantage, it's not running on the computer's hard-drive so can overwrite all of the hard-drive, (including the Operating System, so if you can't reinstall the OS don't wipe the computer's entire hard-drive).

If someone knows enough about computers to create a hidden partition I suspect they will encrypt the data on it. Now the bad news: if youíre in the UK and The Old Bill ask you to make encrypted data on your computer readable, and you donít, (coz you donít know the password), then theoretically you could be be doing porridge as a result ...

http://www.theregister.co.uk/2007/10/03/ripa-decryption_keys_power/
« Last Edit: 03/09/2012 04:04:11 by RD »
 

Offline yamo

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Re: How should I sanitize a secondhand computer
« Reply #8 on: 23/09/2012 16:14:49 »
Buy and install a new hard drive.
 

Offline Mazurka

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Re: How should I sanitize a secondhand computer
« Reply #9 on: 03/10/2012 14:45:30 »
Buy and install a new hard drive.
This. - it is, to quote Ripley, the "...nuke the entire site from orbit - it's the only way to be sure" option
And physically destroy the old one and throw the bits in a fire and divide the ash / slag up and dispose of in differnt bins.
« Last Edit: 03/10/2012 14:49:56 by Mazurka »
 

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Re: How should I sanitize a secondhand computer
« Reply #9 on: 03/10/2012 14:45:30 »

 

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