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Thursday, August 2, 2012

Obtaining USB Device Details

It's very often the desire of Forensics investigators to determine if a particular USB flash drive has been mounted in a computer that is the subject of an examination.  This brief post will not cover the various methods used check the Windows Registry or other OSes for a history of mounted devices, but instead how to extract USB Device details to match to the Windows Registry artifacts.

usbutils

The usbutils package includes the lsusb, a tool to list USB devices.  It can be used to find the device manufacturer (not always apparent from the exterior), the serial number, the vendor ID, and other information that can be used to identify the device in a computer system log or settings file.


The basic command, lsusb, lists all attached usb devices, including hubs:
$ lsusbBus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hubBus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hubBus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching HubBus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching HubBus 002 Device 003: ID 0557:8021 ATEN International Co., Ltd Bus 002 Device 004: ID 0557:2213 ATEN International Co., Ltd CS682 2-Port USB 2.0 DVI KVM SwitchBus 001 Device 004: ID 0930:6545 Toshiba Corp. Kingston DataTraveler 102 Flash Drive / HEMA Flash Drive 2 GB / PNY Attache 4GB StickBus 001 Device 005: ID 1058:1111 Western Digital Technologies, Inc.
The Kingston device is the device of interest.  As you can see, the basic output lets us determine the bus, device number, and vendor id (ID 0930:6545) but not the serial number or other device details.  From the basic help, we can see how to address the specific device of interest to obtain more information:

Usage: lsusb [options]...
List USB devices
  -v, --verbose
      Increase verbosity (show descriptors)
  -s [[bus]:][devnum]
      Show only devices with specified device and/or
      bus numbers (in decimal)
  -d vendor:[product]
      Show only devices with the specified vendor and
      product ID numbers (in hexadecimal)
  -D device
      Selects which device lsusb will examine
  -t
      Dump the physical USB device hierarchy as a tree
  -V, --version
      Show version of program
Therefore, to obtain a full set of details of the Kingston flash drive, we can use the -D option and provide the device path as an argument.  We determine the device path using the Bus/Device information from the base lsusb output.  Because we are adressing a device, we need root privileges, so su to root or use sudo:

# lsusb -D /dev/bus/usb/001/004
Device: ID 0930:6545 Toshiba Corp. Kingston DataTraveler 102 Flash Drive / HEMA Flash Drive 2 GB / PNY Attache 4GB Stick
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x0930 Toshiba Corp.
  idProduct          0x6545 Kingston DataTraveler 102 Flash Drive / HEMA Flash Drive 2 GB / PNY Attache 4GB Stick
  bcdDevice            1.00
  iManufacturer           1 Kingston
  iProduct                2 DT 101 G2
  iSerial                 3 001CC0EC346EEC11########  (redacted)
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           32
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              200mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         8 Mass Storage
      bInterfaceSubClass      6 SCSI
      bInterfaceProtocol     80 Bulk-Only
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)
As you can see, we get a nice, report worthy display of the device details, including the serial number.  The output can be redirected to a file with the usual redirection operators, or sent to the terminal and a file at the same time with the tee command:
# lsusb -D /dev/bus/usb/001/004 | tee device_details.txt
Finally, the verbose option can be used to obtain the same device details as the -D option and without the need to exercise root privileges or address the device, but there's a catch: you get verbose output of all USB devices.  Pick your poison.

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