Intel Management Engine flash

[sa91]

Hello.

Computer has been compromised (files & typestreams find themselves elsewhere).

Appears malware is not in the (full-disk bitlocker protected) Windows/Drivers/Apps/Data partition - Believe can say this as booted from a Linux Live-CD, the bitlocker partition was not visible yet the malware remained active.

Conclude malware is stored in either a) the System Reserved partition or b) the firmware.

(No AV product has identified anything suspecious although they do not appear to make specific reference to the System Reserved partition)

Have already re-flashed the BIOS and re-intalled the Intel Management Engine (IME) driver (appears not to include firmware).

Wish to re-flash the IME firmware (ideally, all other firmware in computer as well).

Cannot find any firmware in the HP site other than BIOS.

Kindly assist with a) determining the precise (non-ROM only, given issue) firmware/microcode/etc areas in specific computer and b) finding the code from HP/a reliable source.

Latest BIOS (L73_0149) (re)installed, windows 10x64 up to date, drivers up to date, though these should not make any difference.

Apologies for long text, trying to be precise,

Thank you v much,