How to use HP Laserjet printer firmware update utility on El Capitan 10.11? 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.



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'.



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.
https://support.hp.com/us-en/product/hp-laserjet-p2055-printer-series/3662052/document/c02008627

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!