I am a victim of gang stalking and have discovered that somebody has installed the PRET printer exploitation toolkit (github.com/RUB-NDS/PRET) on my HP Laserjet P2055dn printer.

I wish to re-install the firmware from the Hewlett Packard support website (support.hp.com/us-en/drivers/selfservice/hp-laserjet-p2055-printer-series/3662052).

The latest version of the HP Laserjet Firmware Update Utility only is for OS X 10.7 Lion, and there is nothing to download and use for later versions of OS X.

enter image description here

I am using El Capitan 10.11.

When I download and try to open the DMG file (ljp2055_Firmware_Update_Utility_20141201.dmg) I am unable to open the file, and get an error message saying 'The following disk images couldn't be opened: image not recognised'.

enter image description here

I have tried opening the DMG file with Disk Utility to no avail.

I do not have access to Microsoft Windows at all currently. I need to extract the necessary .RFU file, and then re-install the printer's firmware.

Does anyone have any ideas on how I can get this done?

Thanks in advance.

  • 1
    The DMG appears to be corrupt, regardless of the version of macOS. diskutil mountDisk $(hdiutil attach -imagekey diskimage-class=CRawDiskImage -noverify -nomount ~/Downloads/ljp2055_Firmware_Update_Utility_20141201.dmg) doesn't seem to help. Running it through DiskWarrior crashes the program.
    – grg
    Commented May 23, 2017 at 9:32
  • DiskWarrior is a great idea! Just need to dig out my old licence code, as I've had a few Mac crashes since last I used it. Commented Jul 22, 2017 at 16:48

1 Answer 1



This article from HP describes how you can update your printer firmware with LPR, a Mac/Unix terminal utility. You should not need the firmware update tool to update your printer’s firmware with this method. Best of luck!


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