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Study: 78% of Resold Drives Still Contain Readable Personal or Business Data (consumerist.com) 207

itwbennett writes: Blancco Technology Group, which specializes in data erasure, bought 200 secondhand PC storage drives (PDF) from eBay and Craigslist to see if they could recover any of the old data saved inside. Their findings: 78 percent of the drives contained residual data that could be recovered, 67 percent still held personal files, such as photos with location indicators, resumes and financial data, and 11 percent of the drives also contained company data, such as emails, spreadsheets and customer information. Only 10 percent had all the data securely wiped, Blancco said. The Consumerist points out that Blancco makes their money from promising secure data erasure, so the company has a "strong and vested interest in these results." As for why so many of the drives contain unwanted information, the report says it has to do with the difference between "deleting" data and "erasing" data. Your files aren't actually deleted when you drag them to the Trash or Recycle Bin, or by using the delete key -- shocking, I know. You can format a drive to erase the data, but you have to be careful of the format commands being used. A quick format, which was used on 40% of the drives in the sample, still leaves some residual data on the drive for someone to possibly access. A full format, which was used on 14% of the drives, will do a better job in removing unwanted files, but it too may still miss some crucial information. The solution Blancco recommends: buy a tool to perform complete data erasure.
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Study: 78% of Resold Drives Still Contain Readable Personal or Business Data

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  • Simple under linux (Score:5, Insightful)

    by Anonymous Coward on Wednesday June 29, 2016 @05:08AM (#52411665)

    dd if=/dev/zero of=/dev:sdb

    or for the paranoid

    dd if=/dev/urandom of=/dev/sdb

    Why buy an expensive product when a simple one-liner will do the same job

    • by gweihir ( 88907 ) on Wednesday June 29, 2016 @05:18AM (#52411687)

      Was about to post that. For a nice progress indicator, use

      dd_rescue -w /dev/zero /dev/target

      Apparently, a single zero-overwrite is entirely enough for modern disks (say, newer than 15 years or so), as these are used close enough to the surface data density limit that even magnetic force microscopy can recover a few scattered bits at best after a zero-wipe.

      I think the main problem here is that to do something like this under Windows, you have to jump through some hoops. And the other main problem is (of course) that people do not understand how disk storage works in the first place.

      • Re: (Score:3, Informative)

        If you're decommissioning an online disk, the simplest solution would be to boot one of the live-distro Linuxes and run dd on it.

        Of course, that does require a certain minimum level of competence. More, perhaps than you'd find in a PHB, but less than you'd find in a hamster.

        • Re: (Score:2, Funny)

          by Anonymous Coward

          If you're decommissioning an online disk, the simplest solution would be to boot one of the live-distro Linuxes and run dd on it.

          Or you could just let Windows update itself to Win10 and then try to rollback to Win7, by all accounts that's just as effective at deleting your data.

        • by Sloppy ( 14984 )

          No, the simplest solution is to simply not ever bother putting the decryption key on that drive. That way, when the drive fails and you're unable to write to it, your work has already been done.

      • by Dr_Barnowl ( 709838 ) on Wednesday June 29, 2016 @05:59AM (#52411829)

        You don't need to do it under Windows though - burn a Linux USB and off you go.

        Hell, there's a bootable image just for it : Darik's Boot and Nuke [dban.org]

        Blancco are just capitalising on ignorance (and risk-aversion in the business community which only tends to regard something you pay for as being a safe bet, despite the usual license agreements which preclude the vendor having any liability anyway).

        • by Dr_Barnowl ( 709838 ) on Wednesday June 29, 2016 @06:01AM (#52411837)

          Hah, hadn't realized that Blancco is apparently just the monetization of DBAN.

        • by gweihir ( 88907 )

          That already qualifies as a number of hoops for the average user, and that is the problem. Apparently, even googeling "erase disk" is far too complicated for the average user. Of course, you and me will have that Linux boot CD/DVD/USB-key already laying around, but the average user is apparently so limited that companies like Blancco make good business on something that is easy to do with free tools.

          DBAN is nice though. Had not heard of it before.

        • "burn a Linux USB"

          WTF???

        • by Bert64 ( 520050 ) <bert.slashdot@firenzee@com> on Wednesday June 29, 2016 @06:43AM (#52411973) Homepage

          Interestingly a few organisations have been bitten in the past, for instance by dos-based commercial disk wiping software which only wiped the first 8GB of any drive. I've even encountered a company that wanted to continue using such software because it was "much quicker at wiping large drives" which isn't surprising given that it doesn't wipe the whole drive.

        • Blancco isn't just capitalizing on ignorance, it is a tool for people who need reports on each drive's wipe. Anyone can do a dd if=/dev/zero of=/dev:sdb (or similar) but can you report back that it was actually done, in a certified report? Blancco can, and that is a major and valid selling point.

          On the otherhand, you can just degauss the damn drive and ruin it without breaking it with a hammer. http://www.garnerproducts.com/ [garnerproducts.com]

          • by gweihir ( 88907 )

            Unless it is a report digitally signed by a secure erase device, that report is worth about as much as a person certifying the erasure.

      • by Trogre ( 513942 )

        Apparently, a single zero-overwrite is entirely enough for modern disks (say, newer than 15 years or so), as these are used close enough to the surface data density limit that even magnetic force microscopy can recover a few scattered bits at best after a zero-wipe.

        Well, yes, but many modern disks don't have a surface to speak of. cf SSDs

        • by gweihir ( 88907 )

          By "modern disk" I mean "disk", not "disk emulator" (what an SSD essentially is), of course.

          For an SSD, if you want an "eBay safe" erase, just do the zeroing. Some expensive data-recovery software may still recover buffers and the like. If you need more, do physical destruction. You cannot really trust that the ATA "Secure Erase" command does what it claims.

          But the whole discussion here is not about disks with any really high-value data on them. For those, always do full zeroing, ATA Secure Erase (if an SSD

      • by Bert64 ( 520050 )

        You can always download DBAN, just burn it to cd and boot.

      • I use "shred", part of coreutils on Fedora. I wouldn't be surprised if it was common on other distros.
      • I've been using
        shred -vf -n 1 /dev/target
        myself to overwrite with pseudo-random data. Seems to come with pretty much every Linux distro, and appears to be purpose-built for secure erasure. It supplies a regular progress update, allows for multiple passes (hence the 1, it defaults to 3), and even allows for a final "zero pass" for the paranoid who want to hide the fact that they did a secure delete.

      • by emil ( 695 )

        Use shred -n 7 /dev/sda - dd is hardly sufficient, especially if my finances are involved.

        NAME shred - overwrite a file to hide its contents, and optionally delete it
        SYNOPSIS shred [OPTION]... FILE...
        DESCRIPTION
        Overwrite the specified FILE(s) repeatedly, in order to make it harder
        for even very expensive hardware probing to recover the data.
        Mandatory arguments to long options are mandatory for short options
        too.
        -f, --force change permissions to allow writing if ne

        • by adolf ( 21054 )

          dd is sufficient. It doesn't have to be zeros -- it could be /dev/random or a long series of concatenated goatses: Once the bits are set into different byte patterns, nobody can tell what the previous bytes were anymore.

          They used to be able to recover some data using a process called magnetic force microscopy, but those days are gone and the process was/is expensive enough that your financial data wasn't a cost-effective proposition.

          One thing that none of these high-level software erasure techniques can d

    • Darik boot and nuke is a Linux distribution designed to wipe out the drive for the extremely paranoid. With an easy to use menu interface.

    • Wrong,
      shred --verbose /dev/sda5
      for the GNU world.
      Most Windows orientated users will have a file compression program and most antivirus have a shred utility to securely delete files, you can get linux ISO images that shred every disk on a computer as well.
      The only thing worse than being insecure is thinking your secure when your not.

    • dd if=/dev/zero of=/dev:sdb

      That just fills your / partition with a file called dev:sdb and causes nothing good.

      dd if=/dev/urandom of=/dev/sdb

      That is incredibly slow, as output is slowed down to better get the random pool filled.

    • by plover ( 150551 )

      Simple, but wrong.

      Consider that your drive might have detected some anomaly while updating the sector containing your secret, and migrated some of your super-secret data away from the suspect sector to another, then marking the original sector as bad. No amount of overwriting will ever overwrite the bad sector, as the drive electronics will not allow it. That data is there permanently.

      If you need to really secure your data, the time to do it is before you write it to a device that was designed to not lose

    • Why buy an expensive product when a simple one-liner will do the same job

      What if there's a problem with the physical drive that prevents the system from recognizing it, or writing data to it?

      Doing a dd is also very time consuming. If I had to do this routinely I'd invest in a disk punch or shredder.

  • Encrypt your drives. (Score:3, Interesting)

    by Anonymous Coward on Wednesday June 29, 2016 @05:10AM (#52411671)

    Delete the block containing the keys.

    For this threat model, this is the perfect answer (if you trust the encryption, that is).

    No need for some "secure erase" snake oil.

    • Re: (Score:3, Funny)

      by donaldm ( 919619 )

      Delete the block containing the keys.

      For this threat model, this is the perfect answer (if you trust the encryption, that is).

      No need for some "secure erase" snake oil.

      You know the cheapest and most secure way to delete your data is to hit the disk a few times with a slegehammer. It's also a great tension reliever. Of course, after you have had a smashing good time please dispose of the part(s) in a responsible manner. :-)

  • by TheReaperD ( 937405 ) on Wednesday June 29, 2016 @05:14AM (#52411677)

    You don't have to buy a secure hard drive erasure tool, DBAN [dban.org] does a reliable job for most drives and is free. SSDs are a new kink in the mix that means that some really advanced tools could retrieve data from the drives, even after a complete wipe but, if you're going up against people that dedicated, I recommend a sledgehammer instead.

    • I recommend a sledgehammer instead.

      While that sounds fun, it likely would be less effective than you might think...

      Or it might be, but can you be sure?

      https://www.semshred.com/conte... [semshred.com]

      • It all comes down to your potential data thief. If it's just some wannabe hacker who buys your drive off ebay, then a tool such a DBAN or the dd commands in linux should do the trick, even for SSDs. If you're up against professional data thieves, you'll want to smash and then have the drive shredded (don't send it to the shredders intact as there have been cases of the drives being resold intact instead; probably by unscrupulous employees). If you're up against the CIA, FSB or the Mossad, dissolve it in

      • by OmniGeek ( 72743 )

        One place where I worked uses a center-punch or hand drill to perforate the disk platters, then bends them with pliers; laptop disk platters tend to be made of glass, and shatter in a most gratifying manner. Physical destruction of the platter is definitely the most effective way to permanently delete its data.

    • DBAN seems to be owned by the company posting the article as well - their front page links to Blancco software and has a comparison chart :

      http://dban.org/download [dban.org]

      Basically, they're capitalising on corporate dipshittery. It's impossible to attest to the destruction of digital data, because it's so readily copyable. If you must be sure that a given data vessel is unrecoverable, then physically destroy it - unless it's something exotic, it will be cheaper than all that paperwork.

      There are some useful features

      • Yea, it sad that they were bought. But, use the free tool. If it's important enough that you would need the professional product, just destroy the drive and be sure.

    • by AmiMoJo ( 196126 )

      Many SSDs support encryption with Windows 8+. There is some slow progress on Linux support. With Windows 8.1 manufacturers are required to enable it transparently on their devices if the hardware supports it. For example, Microsoft Surface tablets are fully encrypted by default.

      With encryption by default the user doesn't need to enter a key, that's stored in secure memory on the PC. But when they want to discard that machine they can do an instant secure wipe that takes it back to factory settings, with no

  • Why? (Score:5, Insightful)

    by Calydor ( 739835 ) on Wednesday June 29, 2016 @05:21AM (#52411695)

    Why do people even sell old hard drives, let alone BUY used drives that may be full of bad sectors or viruses?

    • Re:Why? (Score:4, Informative)

      by JoshuaZ ( 1134087 ) on Wednesday June 29, 2016 @05:33AM (#52411731) Homepage
      Because it is cheap, and a single reformat will deal with the vast majority of issues. A few bad sectors aren't in general going to make the drive unusable.
      • Re:Why? (Score:4, Informative)

        by PhunkySchtuff ( 208108 ) <kai&automatica,com,au> on Wednesday June 29, 2016 @05:59AM (#52411831) Homepage

        Modern drives will silently remap sectors without telling you (unless you look at the SMART status).
        Once they exhaust their pool of spare sectors, then they start telling things higher up the chain that there are bad sectors.
        By the time a disk is reporting bad sectors to the OS (as a bad sector, instead of incrementing a SMART counter and silently carrying on) it has remapped so many bad sectors that it can no longer automatically remap them and is now telling you there is a problem.

        In my experience, every single drive that I've seen reporting even a single bad sector will soon go pear-shaped and shouldn't be used.

        • That's the problem with SMART. If it says something is bad, it is. If it says everything is good, you don't really know for sure -- you may just be one bad sector away from hitting the "too many bad sectors to remap them all".

          • by tlhIngan ( 30335 )

            That's the problem with SMART. If it says something is bad, it is. If it says everything is good, you don't really know for sure -- you may just be one bad sector away from hitting the "too many bad sectors to remap them all".

            Huh? There's a SMART attribute that already says "number of remapped sectors". It should be zero. It might hit 1 or 2 if it's a portable drive treated badly, but that's it. Once it starts hitting double digits, the drive is generally going. It may have a few months of error free opera

        • In my experience, every single drive that I've seen reporting even a single bad sector will soon go pear-shaped and shouldn't be used.

          Not that I want to go back to measuring disk size in tens of megabytes, but I do have a certain nostalgia for the days when hard errors would sometimes correct themselves and an unusable sector would become usable again.

    • by houghi ( 78078 )

      Because of money. People want to sell items they no longer need in exchange of money.
      Others would want to pay money for items they want.

      The risk that items are defective is also a reason why they are cheaper and worth the risk to some people. The fact they sell them with personal data is because they were not aware. Otherwise they would have either removed it, or adjusted the price.

    • Why do people even sell old hard drives,

      Because $20 is better than $0 in my pocket.

      let alone BUY used drives that may be full of bad sectors or viruses?

      Because a chance at a lot of personal data is worth $20.

  • If the data in 22% of disks were unrecoverable, either the drives were broken, or the previous owner was very paranoid, or they have been used to store something very valuable.
    • by Bert64 ( 520050 )

      Or perhaps they never had anything on them to start with?
      Many companies keep a pool of spare drives for various reasons (e.g. hot spares incase any fail in a raid array), but these drives are discarded along with the live ones once they become obsolete. It's not uncommon for drives to be disposed of which have never been used at all.

  • by wkwilley2 ( 4278669 ) on Wednesday June 29, 2016 @06:00AM (#52411835)

    I already bought a data erasure tool years ago, it's my trusty 16oz ball peen hammer.

    • I prefer 12 ga slug, 7.62x54r, or .454 casull. Salvage the magnets, properly dispose of the electronics, recycle the aluminum case and spacers. Once the platters have been outside for a few months and are starting to resemble lorraine cheese they also find their way to the recycling.
    • I already bought a data erasure tool years ago, it's my trusty 16oz ball peen hammer.

      I have yet to sell a second hand drive on ebay that's been pounded with a hammer for more than $zero, or in your case -$5 depending on how many drives need peening.

  • by Ukab the Great ( 87152 ) on Wednesday June 29, 2016 @06:02AM (#52411841)

    "Craigslist" and "Hard drive" used in the same sentance I'm expecting either an interesting story or a punchline at the end of it.

  • Simple solution (Score:2, Interesting)

    1) Use one of the many freely available utilities to overwrite the entire drive

    2) Use a script to fill the drive with randomly named copies of goatse, tubgirl and other such wonderful images. Throw some of them into other document formats as well, just to keep things interesting. For added fun, make sure all the MS office documents are infected with macro viruses. Bonus points if the random names are made using a list of enticing words like "password", "private", "taxes", "accounts", etc.

    3) Delete all th

  • I have a hard time seeing how it is worth the effort to sell an old drive. They are worth so little on the used market that it generally seems to make more sense to either toss them in the closet to rot in peace, or seek out a place that can properly dispose of them.
    • by necro81 ( 917438 )
      ,blockquote>or seek out a place that can properly dispose of them

      My place of choice is the old gravel pit, where I can light off small amounts of thermite without much risk. If I'm all out of thermite, the same location serves as a handy shooting range, which also gets the job done, but the noise attracts unwanted attention.

    • I usually get used drives at yard sales, either inside of a used PC or sometimes as an external. Every single time, there has been personal information included. Only once has any of their data been interesting, and it's never been the personal information in my case. They just had a cool mp3 collection.

      • I can confirm the near-ubiquitous presence of personal data - I've been "refurbishing" donated PCs for the local thrift store - basically just a secure delete and Linux install (plus a big "NOTICE: this computer can't run normal programs + details" label on the side to reduce buyer's remorse), and have yet to encounter a computer that has even had the personal data even superficially deleted. Apparently most people don't have any concept of security.

        • by tepples ( 727027 )

          plus a big "NOTICE: this computer can't run normal programs + details" label on the side to reduce buyer's remorse

          Does the label mention Wine, which can run many but not all Windows desktop applications?

          • Actually yes, at the bottom of a short list of suggested applications further down the page. I had even briefly considered pre-installing it, but decided a secure wipe and Linux install was about as much effort as I felt like donating (the store is operated as a funding source for the local homeless shelter)

            I decided a big warning was called for as I had been informed by multiple friends around town that they had seen terrible return rates with Linux PCs, and the thrift store has a no returns policy. Unde

    • "I have a hard time seeing how it is worth the effort to sell an old drive. "

      Mostly, you're right. But if you work in an IT department and have 700 of the blasted things stacked in the corner after an upgrade, it may be worth the effort to gather em up and sell them -- especially if you can use volunteer labor to clear them. Also, if you want to donate your old PC to a charity or sell it at a garage sale, you might want to clear the drive and install a fresh copy of the OS.

    • by Bert64 ( 520050 )

      People sell the machines with the drives still inside, sometimes it can be quite a considerable hassle to remove the drive and doing so significantly decreases the resale value of the laptop as it's no longer a fully working unit.

  • Rather than buy... Use Darik's Boot and Nuke.
    ou still have to cope with Blancco's ads, but it does do the job
    Y

  • by Blaskowicz ( 634489 ) on Wednesday June 29, 2016 @07:57AM (#52412273)

    At least for hard disk drives, what happened to just using the low level tools?
    Historically it was dead easy to run them from DOS. Still looks like it's possible, e.g. with Seagate it's an .iso file that is distributed.

    See there, page 6/20, section G. : (an emphasis added)
    http://www.seagate.com/files/s... [seagate.com]

    Seagate is not responsible for lost user data. Erase Drive is available for Seagate or Maxtor drives only.
    Five choices are available under this section:
      Secure Erase. This method uses the drive firmware to erase the data by overwriting the data
    with zeros. In Enhanced Erase mode, all previously written user data shall be overwritten,
    including sectors that are no longer in use due to reallocation.
    Secure Erase requires a user
    password to run which is deleted at the conclusion of the procedure. If your drive does not have
    a user password, SeaTools for DOS will set a temporary password "idrive" without the quotes.
    This password will be removed at the end of the Secure Erase so you never need to actually use
    it to access your drive. If ... BLAH BLAH BLAH

    No idea if you have a UEFI computer, maybe you need to use BIOS emulation, maybe it works, maybe it doesn't because you lack BIOS emulation etc.
    But then, they've got a Windows version as well. The pdf for that is harder to read says it's from October 2015. It has a changelog.
    It's more terse but says stuff like :
    http://www.seagate.com/files/w... [seagate.com]

    - SED Crypto Erase
    Self-Encrypting Drive Instant Secure Erase. If the drive supports hardware
    encryption, this menu will be displayed. Like Full Erase this command will permanently destroy
    access to all user data on the drive, but will do so by the erasure of the drive encryption key which
    takes less than one minute to complete. Both SAS and SATA drives are supported, but the boot
    drive should not be listed as an available choice.

    - Sanitize Erase
    Write zeros to all user data sectors on the SATA drive including unallocated and
    cache sectors. This command is mostly found on SSD drives

    Failing vendor tools, see what the FLOSS punks have
    https://tinyapps.org/docs/wipe... [tinyapps.org]

    So, a quote, with a bolding on what I thought was fun.

    Explanation

    According to National Institute of Standards and Technology (NIST) Special Publication 800-88: Guidelines for Media Sanitization, Secure Erase is "An overwrite technology using firmware based process to overwrite a hard drive. Is a drive command defined in the ANSI ATA and SCSI disk drive interface specifications, which runs inside drive hardware. It completes in about 1/8 the time of 5220 block erasure." The guidelines also state that "degaussing and executing the firmware Secure Erase command (for ATA drives only) are acceptable methods for purging."
    Benefits

            Can securely wipe most PATA/SATA hard drives manufactured this century
            Reportedly restores peak performance to SSD drives (though SE fails to securely wipe some SSDs) [hummm...]
            hdparm/Linux offers much better hardware support than HDDErase/MS-DOS
    Overwrites blocks marked as bad by the hard drive (which DBAN and similar tools ignore)
            Though speed (vs. block erase wiping tools like DBAN) is often cited, the difference is negligible.*

  • Every couple of years we need to remind everyone why they need to zero out a drive, and not just reformat it. I guess it's that time again.

    Remember kiddies:

    Don't just format - zero out.
    --zero_out

  • Disk Utility > Erase > Security option > Most secure (DOD 5220-22M compliant)

  • 1) Remove the disk, open it up and extract the platter and smash into tiny bits. If it's a metal disc then get some heavy grit sand paper and sand away.

    If you're squeamish about physical destruction, you can always use Darik's Boot and Nuke (DBAN).

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