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

Thanks for your great reply. Specifically my issue is with the printer's firmware, not the drivers for the Mac.

On the HP website there is a downloadable utility that does not have any version advertised above OS X Lion 10.7. HP has not issued a newer version of their utility since Lion. This is about firmware not Mac printer drivers.

The utility is available as a downloadable DMG file that will not open on OS X El Capitan 10.11. I get the error described in my post.

I am trying to discover if I can open that firmware utility DMG file on El Capitan and either make it work on El Capitan, or open the DMG file and extract the .RFU file containing the printer's firmware and transfer it to the printer using FTP or some similar means.

Okay, perhaps this is not specifically a Mac issue, but I am trying to establish if it possible to use the Mac to maintain the printer's firmware. And especially avoid using Microsoft Windows if at all possible.

Nevertheless it is totally amazing to have the link you shared and have up-to-date drivers and I think that is very useful to have.

Thank you again, but my search goes on to use my Mac to fix this printer hardware firmware issue.

Unfortunately I do not have any access whatsoever to a Mac running Lion 10.7, much to my chagrin.

I've speculated today on the possibly of calling Mac support and asking them to make available for download through my Mac App Store account my former licence for Lion, and then installing that as a virtual machine in VMWare Fusion. But that seems a bit steep right now. I am hoping somebody on the forums is going to come through with a way of opening the .DMG file I referred to in the original posting.

All I need is the .RFU file contained within that .DMG download intended for Lion 10.7. I'm not totally sure but I believe I can reinstall the printer's firmware simply by transferring that .RFU file to it via FTP. The actual HP Firmware Update Utility is not necessary to achieve the task - I just need to open the downloaded .DMG container.

Let's see what people can suggest!

Oh, that's really interesting. That's incredibly useful to know. Thank you for doing that and telling me.

I will get back on to HP Support and raise this with them today.

I will try and download the other Printer Firmware Update Utility .DMGs from HP's support website and see what happens. They have versions for OS X 10.5 Leopard and OS X 10.6 Snow Leopard also.

I will report back my findings. Just need to open the .DMG and extract the .RFU file.

Well that was a waste of time. From the HP support site (https://support.hp.com/gb-en/drivers/selfservice/hp-laserjet-p2055-printer-serie s/3662052) the downloads for Leopard and Snow Leopard are exactly the same .DMG file. I suppose that was obvious, but needed to exhaust that possibility.

The HP support site lists Linux, Unix and SAP as other download options when searching for the firmware update options. None of those links provide any access to actual downloadable firmware updates.

There remains the Microsoft Windows download link. I will need to get a Windows device from somewhere, download that Printer Firmware Update Utility and see if I can retrieve the .RFU file. I just feel sad HP does not allow Mac users to remain native to their chosen host platform to perform relatively straightforward firmware maintenance.

Thanks again for opening the .DMG in Lion for me. I will contact HP Support to notify them of this.

Thanks for linking to that information about a Factory Reset. Yes you are correct. But specifically with this thread I want to reinstall the printer's firmware from my Mac. I am not resetting the printer to factory defaults. My printer has been hacked!

I know that this is not specifically a Mac issue, but more than that how many of us would think this possible? Let alone know how to resolve this? Especially as the published support information and download on the HP website does not work when trying to do this from a Mac. The HP website explicitly provides a download to perform this action for MacOS 10.5, 10.6 and 10.7 and that downloaded .DMG file does not even open, let alone provide a working solution.

The problem that I am dealing with is that somebody has installed the PRET printer exploitation toolkit (https://github.com/RUB-NDS/PRET) on my printer.

PRET is a Python program installed inside the printer's system per se, and once there creates copies of all documents sent to the printer, stores those documents inside the printer's memory, and allows attackers to remotely access the printer over the network to retrieve those clandestinely stored copies. So from anywhere in the world others can see what has been printed by your printer.

By reinstalling the firmware I want to see if I can destroy the PRET program by wiping it away. A factory reset is unlikely to wipe low level internal operational programs - that is where is PRET toolkit hides.

I just want to avoid using Microsoft Windows to do the firmware update. Another correspondent on this thread has tried to open the HP Support provided Firmware Update Utility on the version of MacOS intended by HP and has discovered that there is something wrong with the downloaded .DMG file. It won't open and so is presumably corrupted at source on HP's website.

I will be contacting HP Support for their response, and will update this thread as or when they reply.