If it is hard wired or hard-coded, I don't think it could be removed in the normal sense. The physical structure of chips and basic codes would need to be modified. That probably won't be possible.
My Computer
At a glance
Windows 7 Ultimate X64 SP1Intel i5-2550K, Differing ~4.4-4.8GHz No buil...16GB G.Skill Sniper 1866MHz @ 2133MHz 2x8GBASUS GTX650TIB-DC2OC-2GD5, (650TI Boost)
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Home Built Desktop By DataTech
OS
Windows 7 Ultimate X64 SP1
CPU
Intel i5-2550K, Differing ~4.4-4.8GHz No built in GPU
Motherboard
ASUS P8Z68-V PRO/GEN3
Memory
16GB G.Skill Sniper 1866MHz @ 2133MHz 2x8GB
Graphics Card(s)
ASUS GTX650TIB-DC2OC-2GD5, (650TI Boost)
Sound Card
Onboard Realtek 5-1
Monitor(s) Displays
Samsung P2570HD
Screen Resolution
1920x1080
Hard Drives
Samsung 840 Pro 256GB SSD for OS, 500GB Seagate Constellation (Enterprise drive) for Data
PSU
Corsair HX650W
Case
Inwin Dragon Rider
Cooling
Hyper 212 EVO w/two Noctua fans, push-pull, @1300 RPM
Keyboard
E-Z Eyes, bright yellow keys with large characters
Mouse
steelseries SENSEI Laser Pro Gaming
Internet Speed
48-51Mbs Mbs down, 11 Mbs up Xfinity Cable
Antivirus
Norton Internet Security 2013
Browser
IE 10, Opera, Pale Moon if needed
Other Info
4 case fans, LG BluRay-RE, ASUS DVD-RW, Mr. Fusion power supply, 1.21 gigawatts.
If you know what you are doing it isn't that hard to add extra code to a bios file or a devices firmware. Routers switches and other network equipment have updateable firmware just like you can update the BIOS on a PC. You could add code to let you log in though a back door. Or add code to simply disable said device remotely. To get ride of the maleware you would have to flash the chip on the device with a known good BIOS or firmware file. If the chip can't be reprogrammed you would have to replace the chip or scrap the device. Even digital picture frames and MP3 players could have infected files added. That free sample loads a Trojan or root kit when you view it or play the song.
My Computer
At a glance
Windows 10 Education 64 bitAMD Phenom II X4 980 Black Edition Deneb 3.7GHz8GB 4GBx2 Kingston PC10600 DDR3 1333 MemoryZotac NVIDIA Geforce GT640 2 Gig DDR3 PCIe
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Home Built
OS
Windows 10 Education 64 bit
CPU
AMD Phenom II X4 980 Black Edition Deneb 3.7GHz
Motherboard
Asus M4N68T-M V2 µATX Motherboard
Memory
8GB 4GBx2 Kingston PC10600 DDR3 1333 Memory
Graphics Card(s)
Zotac NVIDIA Geforce GT640 2 Gig DDR3 PCIe
Sound Card
VIA VT1708s High Definition Audio 8-channel Onboard
1x Seagate ST3500418AS 500G SATA2 HDD
1x Western Digital Caviar SE16 500G SATA2 HDD
1x Western Digital Caviar SE16 750G SATA2 HDD
2x Western Digital Caviar Green 2TB SATA2 HDD, configured RAID1
PSU
OCZ EliteXtream OCZ1000EXS 1000W ATX12V 20/24 Pin Active PFC
Case
Antec 1200
Cooling
Swifteck H2O-220 Ultima XT Liquid Cooling w/ 320 Radiator
Keyboard
Logitech G11 Keyboard
Mouse
Logitech MX518 Optical Mouse
Internet Speed
Cable Modem
Other Info
Visiontek TV Wonder 650 Theater PCI-E TV Tuner Card
Logitech 9000 Pro Web Camera
Logitech Cordless RumblePad 2 game controller
LG 18x SuperMulti SATA2 DVD Writer
NmediaPC CR98 Multi Card reader
Nmedia Pro-LCD
Corsair Dominator Memory Fan
Coolermaster R4-L2R-20ac 120mm Case Fan x2