Slashdot stories can be listened to in audio form via an RSS feed, as read by our own robotic overlord.

 



Forgot your password?
typodupeerror
Hardware Hacking China Data Storage It's funny.  Laugh. Build Hardware

Magical Chinese Hard Drive 347

Posted by Soulskill
from the finally-a-use-for-old-flash-drives dept.
jamax writes "From TFA: 'A Russian friend .... works at a hard-drive repair center in a Russian town, located near the Chinese border. A couple of days ago a customer brought a broken 500GB USB-drive that he had bought in a Chinese store across the river, for an insanely low price. But the drive was not working: if you, say, save a movie onto the drive, playing the saved movie back resulted in replaying just the last 5 minutes of the film.' Apparently, the contents of the external HDD box included: two nuts, glued to the inner surface of the box with a 128MB flash drive wedged between them (image). And it was a clever hack, too — if ever an attempt was made to write a file that's too large, it got cycled — rewriting itself over and over from the beginning, while leaving the existing files intact. And it reported everything correctly — file sizes and all!"
This discussion has been archived. No new comments can be posted.

Magical Chinese Hard Drive

Comments Filter:
  • Re:Bloody well done. (Score:5, Informative)

    by fuzzyfuzzyfungus (1223518) on Friday April 08, 2011 @12:59PM (#35760650) Journal
    I haven't seen the principle applied to faking an HDD before; but the same phenomenon crops up fairly frequently with USB flash drives and flash memory cards sourced from suspiciously cheap ebay sellers and similar places.

    The cruder examples are simply a low-capacity drive, with a high capacity label, and a specially doctored partition table and fat32 filesystem written to them. Simply reformatting them will reveal their true size and make them safely usable(to the degree that you would trust the quality of such a device...).

    The more sophisticated ones have doctored firmware in the chip that handles abstracting the raw flash into a USB mass storage device, and the OS will detect their false size. You can only determine the true size empirically: exactly what behavior the fake blocks will exhibit varies(all zeros, all ones, garbage); but the real blocks will behave normally. If you are a gambling sort, you can put a partition of exactly that size on the drive and hope for the best; but that isn't really advisable...

    Every abstraction layer is a potential lie, I suppose.
  • data recorder (Score:4, Informative)

    by mugnyte (203225) on Friday April 08, 2011 @01:03PM (#35760700) Journal

    These devices aren't even made specifically for this hack. These are common data recorders for weather stations, EDR's for autos, etc. The genius here was probably more in the acquisition of the case and label.

  • by EkriirkE (1075937) on Friday April 08, 2011 @01:03PM (#35760702) Homepage
    I bought a 2GB micro SD off ebay for cheap, received it and it reported the size correctly, except when it got past 32MB (yes megabytes) i got IO errors. Turns out, the FAT table was written as 2GB on a 32MB card. Writing zeroes then reformatting revealed only 32MB partition onward.
  • Re:Bloody well done. (Score:5, Informative)

    by dgatwood (11270) on Friday April 08, 2011 @01:53PM (#35761404) Journal

    She complained, but being eBay, they did nothing.

    This is why you complain to your credit card company instead. Then eBay has a choice of either eating the loss or going after the seller.

  • Re:Bloody well done. (Score:5, Informative)

    by eulernet (1132389) on Friday April 08, 2011 @05:55PM (#35763946)

    I got 2 different keys of the latter sort (after format, it reports 32Gb, but they really are 4Gb).
    BTW, I don't use them, since I didn't find any way to only use the first 4Gb.

    There is no magic.
    When you write a byte at a given location (for example at 9Gb), it's written at this location modulo 4Gb (in my example at 1Gb), and there is a little protection for the first megabytes, so that the FAT32 is not overwritten when the key is full, to avoid revealing that the key is fake.

    When you buy an USB key, ALWAYS use CheckFlash:
    http://mikelab.kiev.ua/index_en.php?page=PROGRAMS/chkflsh_en [mikelab.kiev.ua]
    In a few minutes, it will tell you if your USB key is correct.

    With my first fake one, I get the first error:
    Error at address F5E56000h: expected "10101010", found "00000000".
    and everything after that is dead.

    With the second fake one, I get the errors:
    Error at address EF800000h: expected "10101010", found "00000000".
    Error at address EF82C000h: expected "10101010", found "00000000".
    Error at address EF928000h: expected "10101010", found "00000000".
    Error at address EFA24000h: expected "10101010", found "00000000".
    Error at address EFB20000h: expected "10101010", found "00000000".
    Error at address EFC1C000h: expected "10101010", found "00000000".
    Error at address EFD18000h: expected "10101010", found "00000000".
    Error at address EFE14000h: expected "10101010", found "00000000".
    Error at address EFF10000h: expected "10101010", found "00000000".
    Error at address F000C000h: expected "10101010", found "00000000".
    after that, the errors are more irregular.
    Note that the write speed is 5.7Mb/s for the first 4Gb of the key, and 25Mb/s after that.

EARTH smog | bricks AIR -- mud -- FIRE soda water | tequila WATER

Working...