iMac is suddenly not recognizing Officejet 6700

[Beagle2]

This printed, which worked with my MacPro, was working fine with an iMac I got a few months ago. Out of the blue today I started getting the following error messages:  

.pde plug in will damage your computer

This file was downloaded on an unknown date

Report Malware to Apple to protect other users

Injet4.driver will damage your computer

HPDM.framework will damage your computer

Worked with Apple support, downloaded the HP drivers and tried to install it got the same messages. Removed the printer and added it again. Printer works fine plugged into a PC laptop in the house.

[BryanCustomPure]

Try this set/order below to get up and running again:

Use the HP Uninstaller: https://support.hp.com/us-en/document/c02440673
If you still have a folder marked HP, delete it (likely here: /Library/Printers/hp ).

Use Easy Start ( https://support.hp.com/us-en/drivers/selfservice/hp-easy-start/7376041  - make sure your OS is correct) and see if your printer is supported. If not, or this doesn't solve the issue,  move on to the next steps.

Uninstall your printer USING THIS METHOD ONLY (NOT EASY START, NOT EASY ADMIN): Apple Logo (Upper Left of Screen)/System Preferences/Printers & Scanners. Then restart your computer.

See if you can print. If not, continue:
Download (and install) this package (From HP FTP) which will update drivers AND THE CERTIFICATE:
ftp://ftp.hp.com/pub/softlib/software12/HP_Quick_Start/osx/Installations/Essentials/hp-printer-essen...  
If the link comes up blank, try right/control clicking and saving it. Or right/control click and copy link, and paste into browser bar. If you get the malware warning part-way through the installation, go to System Preferences>Security & Privacy where you can tick a box and unblock the HP option.

The install takes a bit. Let it run, even if it seems like it stalled out! When it completes, restart.

Then reinstall your printer using: Apple Logo (Upper Left of Screen)/System Preferences/Printers & Scanners, and use the default drivers. If drivers do not show up, download and install the 5.1 driver package from here: https://support.apple.com/kb/dl1888?locale=en_US . Then restart your computer.

[Beagle2]

Many thanks Bryan...I will try this. Thanks again!