Is there any legitimate reason why mouse would register as keyboard AND mouse in BIOS?

[kamamam]

Whenever I boot my computer it displays the USB devices connect to it with quick count summary as such:

I didn't bother taking screenshot for every event that happened but that should clear things up.

 

I started noticing after a while that there were 2 KBDs, 1 MICE, 1 MASS, 0 HUBs. Mass storage is expected, so is a mouse and a keyboard but there's a second keyboard?

As I programmer I understand that it could potentially mean a keylogger, there were no other keyboards attached, so I unattached literally everything until only a single display was attached (to see the update).

By removing and adding devices to the USB ports I found out that it's my mouse that adds additional MICE and KBD entry. So it ends up as "2 KBDs, 1 MICE".

My mouse is Rampage SMX-R80.

I went to look to Device Manager, under mouses I found: "HID-compliant mouse", none of its properties actually tells me it's brand or identification.

I think because it's generic Microsoft driver that handles the mouse preventing mouse's hardware to talk to my hardware directly.

Under keyboards I found two seemingly identical entries: "HID Keyboard Device".

 

So I went to System Information, went to Components > Input > Keyboard, and found this strangeness:

Description	HID Keyboard Device
Name	Enhanced (101- or 102-key)
Layout	00000415
PNP Device ID	[NAH]
Number of Function Keys	12
Driver	c:\windows\system32\drivers\kbdhid.sys (10.0.17763.1, 43,50 KB (44.544 bytes), 15/09/2018 08:28)
	
Description	USB Input Device
Name	Enhanced (101- or 102-key)
Layout	00000415
PNP Device ID	[NAH]
Number of Function Keys	12
Driver	c:\windows\system32\drivers\hidusb.sys (10.0.17763.1, 42,50 KB (43.520 bytes), 15/09/2018 08:28)

Then Components > Input > Pointing Device, and found seemingly normal entry:

Hardware Type	USB Input Device
Number of Buttons	0
Status	OK
PNP Device ID	[NAH]
Power Management Supported	No
Double Click Threshold	Not Available
Handedness	Not Available
Driver	c:\windows\system32\drivers\hidusb.sys (10.0.17763.1, 42,50 KB (43.520 bytes), 15/09/2018 08:28)

 

My question is, is there a valid reason on why my mouse would additionally pretend to be a keyboard? It has a button for going back as well what appears to be a macro button (with a boxed M shape) which changes behavior of scroll-whell press, if disabled, it behaves normally, if enabled it toggles mute on the entire computer.

[geo3]

If it's programmable it likely has  the ability to send keystrokes, and would need to be identified to the system as a keyboard to do that.

[SpaceGhostC2C]

Just now, geo3 said:

If it's programmable it likely has  the ability to send keystrokes, and would need to be identified to the system as a keyboard to do that.

Yes, my best guess is the extra buttons as well.

Many peripherals, including (at least the older) Corsair Commander, for example, show up as HIDs in Device Manager, and then the relevant software leverages that to interact with the hardware.