Tweet
Tweet

Slide 1

Slide 1 text

Analytics, and Scalability, and UEFI exploitation! Teddy Reed [email protected] “Oh My!”

Slide 2

Slide 2 text

demo= Funmo.begin() firmware = "efi" usb:0.present = "TRUE" usb:0.deviceType = "hid" usb:0.port = "0" usb:0.parent = "-1" firmware = "efi" efi64.filename = “/Users/theo/Buffers/ uefi-research/samples/vmware/ efi-trojaned.rom" usb:0.present = "TRUE" usb:0.deviceType = "hid" usb:0.port = "0" usb:0.parent = "-1" Two blank VMs installing standard Windows 7 SP1 or Windows 8 Pro

Slide 3

Slide 3 text

Objectives Demonstrate evil data science using firmware updates Enable audience, researchers, and developers to discover firmware vulnerabilities Release some code and have fun! Introduce firmware & UEFI pentesting 1. 2. 3. 4.

Slide 4

Slide 4 text

Overview::Init() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks We’ll keep track of what capabilities and tools are released throughout this presentation.

Slide 5

Slide 5 text

#define Introduction UEFI Unified Extensible Firmware Interface UEFI Forum: 227 Members (11 are promoters) Windows 8 logo required UEFI Secure Boot Almost every IS/BV, OEM implements UEFI Image © 2005, 2014 Square Enix

Slide 6

Slide 6 text

#define Introduction Security Pre-EFI Initialization Driver Execution Boot Device Select System Load Runtime Services Execute Boot loader “MBR” Select PXE SSD CD-ROM Execute EFI- Application Execute device, bus service drivers Create EFI- services CPU Initialize Board Initialize Measure, Verify OS-aware EFI services OS is running UEFI Unified Extensible Firmware Interface

Slide 7

Slide 7 text

#define Introduction Security Pre-EFI Initialization Driver Execution Boot Device Select System Load Runtime Services Execute Boot loader “MBR” Select PXE SSD CD-ROM Execute EFI- Application Execute device, bus service drivers Create EFI- services CPU Initialize Board Initialize Measure, Verify OS-aware EFI services OS is running EFI Bootkits Secure Boot Attacks Variable Attacks UEFI Unified Extensible Firmware Interface

Slide 8

Slide 8 text

#define Concepts Security Pre-EFI Initialization Driver Execution Boot Device Select Select PXE SSD CD-ROM Execute device, bus service drivers Create EFI- services CPU Initialize Board Initialize Measure, Verify UEFI Unified Extensible Firmware Interface

Slide 9

Slide 9 text

#define Concepts UEFI Unified Extensible Firmware Interface UEFI defines update mechanisms & formats System vendors often choose their own Each vendor distributes updates uniquely similarly to most software vendors

Slide 10

Slide 10 text

Unifying UEFI Updates “That’s a Triple U, all the way!” Simple JSON-representation of UEFI update context information • Release Time • Criticality • Affected Products • Patch Notes • Update Binary(ies) • Dell • Lenovo • Gigabyte • ECS • HP • Intel • MSI • AsRock […] #! FORK ME https://github.com/theopolis/uefi-spider

Slide 11

Slide 11 text

Unifying UEFI Updates “That’s a Triple U, all the way!” Optiplex 9020 A00 2013-06-05 07:12:30 A02 2013-09-23 03:08:01 A01 2013-07-16 07:21:46 ?? ????-??-?? ?:??:?? A03 2013-09-23 08:41:01 A07 2014-01-16 00:00:00 A04 2013-11-25 05:23:27 A05 2013-12-18 00:00:00 https://github.com/theopolis/uefi-spider

Slide 12

Slide 12 text

Unifying UEFI Updates “That’s a Triple U, all the way!” https://github.com/theopolis/uefi-spider Optiplex 9020 A00 2013-06-05 07:12:30 A02 2013-09-23 03:08:01 A01 2013-07-16 07:21:46 ?? ????-??-?? ?:??:?? A03 2013-09-23 08:41:01 A07 2014-01-16 00:00:00 A04 2013-11-25 05:23:27 A05 2013-12-18 00:00:00 What happened to A06, why are A02/03 5 hours apart?

Slide 13

Slide 13 text

Update Ecosystem Vendor Updates UEFI Size Format Feeling Dell 3214 384 9.81G HDR/PFS :| Intel 1193 1193 6.36G Capsule :) HP 2359 397 13.40G Flash/Logo :( Lenovo ?? 193ish 2.58G Capsule D:< ASRock 3092 481 4.64G Flash :) Gigabyte 5176 412 6.94G Flash :) MSI 1138 507 3.85G Flash :)

Slide 14

Slide 14 text

Update Ecosystem Vendor Updates UEFI Size Format Feeling Dell 3214 384 9.81G HDR/PFS :| Intel 1193 1193 6.36G Capsule :) HP 2359 397 13.40G Flash/Logo :( Lenovo ASRock 3092 481 4.64G Flash :) Gigabyte 5176 412 6.94G Flash :) MSI 1138 265 3.85G Flash :) ECS While scraping: ! Only 1 NullPointerDereference! Only 1 JScript injection vulnerability!

Slide 15

Slide 15 text

Update Ecosystem Vendor Updates UEFI Size Format Feeling Dell 3214 384 9.81G HDR/PFS :| Intel 1193 1193 6.36G Capsule :) HP 2359 397 13.40G Flash/Logo :( Lenovo ASRock 3092 481 4.64G Flash :) Gigabyte 5176 412 6.94G Flash :) MSI 1138 265 3.85G Flash :) ECS Also, I would HATE to be Lenovo’s DB designers or on their update data entry team… ! Twice as many exceptions!

Slide 16

Slide 16 text

Update Ecosystem Total size of updates: 54,204,997,483 Size after dedup: 21,722,824,704

Slide 17

Slide 17 text

Overview::recon() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks

Slide 18

Slide 18 text

What’s in an update? There are tons of wacky code/data embedding examples { { { { Firmware Capsule/ Flash Descriptor Firmware Volumes Firmware FileSystem Tiano/EFI NTFS FAT Padding Raw Firmware File Firmware File Firmware File Encapsulation Firmware File Firmware File Firmware File Depex Exp UEFI PE32 MORE!?!?! MEbx iAMT Trojans PM Configs Microcode

Slide 19

Slide 19 text

What’s in an update? There are tons of wacky code/data embedding examples { { { { Firmware Capsule/ Flash Descriptor Firmware Volumes Firmware FileSystem Tiano/EFI NTFS FAT Padding Raw Firmware File Firmware File Firmware File Encapsulation Firmware File Firmware File Firmware File Depex Exp UEFI PE32 MORE!?!?! MEbx iAMT Trojans PM Configs Microcode

Slide 20

Slide 20 text

RCEing Updates #! FORK ME There are a few awesome Firmware Volume, BIOS/ROM, and Flash filesystem parsers Nikolaj Schlej: https://github.com/NikolajSchlej/UEFITool https://github.com/theopolis/uefi-firmware-parser Python module for manipulating firmware-related structures, including: Dell updates, Intel ME, UEFI FV/FD/FFSs/FFs/FSs and Capsule, etc

Slide 21

Slide 21 text

RCEing Updates https://github.com/theopolis/uefi-firmware-parser Print Extract Inject Replace Maintain integrity where possible, optionally regenerate CRCs, add padding if needed One-stop tool for manipulating deeply embedded commodity firmware-objects For good: and evil:

Slide 22

Slide 22 text

demo.inspect! theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_injector.py --guid c57ad6b7-0515-40a8-219d-551652854e37 --injection ./evil.efi ./efi64.rom -o efi-trojaned.rom [#] Opening firmware as UEFI firmware volume. Parsing FV at index (volume). [#] Firmware objects parsed. [#] Injecting (replacing) FirmwareFile c57ad6b7-0515-40a8-219d-551652854e37. [#] Regenerating firmware children structures (from injection point). [#] Regeneration complete, child objects parsed. [#] Rebuilding complete firmware with injection. ffs size mismatch old=3715000 new=3115389 599611 [#] Rebuild complete, injection successful. Wrote: efi-trojaned.rom [#] Injected firmware written to efi-trojaned.rom. theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_parser.py ./efi64.rom Parsing FV at index (0x0). Firmware Volume: 8c8ce578-8a3d-4f1c-3599-896185c32dd3 attr 0x0007feff, rev 2, size 0x200000 (2097152 bytes) Firmware Volume Blocks: (32, 0x10000) File 0: 1b45cc0a-156a-428a-62af-49864da0e6e6 (EFI_PEI_APRIORI_FILE_NAME_GUID) type 0x02, attr 0x00, state 0x07, size 0x2c (44 bytes), (freeform) Section 0: type 0x19, size 0x14 (20 bytes) (Raw section) File 1: df1ccef6-f301-4a63-6196-fc6030dcc880 type 0x03, attr 0x00, state 0x07, size 0x3a04 (14852 bytes), (security core) Section 0: type 0x10, size 0x39cc (14796 bytes) (PE32 image section) Section 1: type 0x15, size 0x14 (20 bytes) (User interface name section) Name: SecMain Section 2: type 0x14, size 0xc (12 bytes) (Version section section) File 2: ffffffff-ffff-ffff-ffff-ffffffffffff type 0xf0, attr 0x00, state 0x07, size 0x68 (104 bytes), (ffs padding) File 3: 52c05b14-0b98-496c-3bbc-04b50211d680 type 0x04, attr 0x10, state 0x07, size 0x9a98 (39576 bytes), (pei core) Section 0: type 0x19, size 0x1c (28 bytes) (Raw section) Section 1: type 0x10, size 0x9a44 (39492 bytes) (PE32 image section) Section 2: type 0x15, size 0x14 (20 bytes) (User interface name section) Name: PeiCore Section 3: type 0x14, size 0xc (12 bytes) (Version section section) File 4: ffffffff-ffff-ffff-ffff-ffffffffffff type 0xf0, attr 0x00, state 0x07, size 0x68 (104 bytes), (ffs padding) [……]

Slide 23

Slide 23 text

demo.inspect! theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_injector.py --guid c57ad6b7-0515-40a8-219d-551652854e37 --injection ./evil.efi ./efi64.rom -o efi-trojaned.rom [#] Opening firmware as UEFI firmware volume. Parsing FV at index (volume). [#] Firmware objects parsed. [#] Injecting (replacing) FirmwareFile [#] Regenerating firmware children structures (from injection point). [#] Regeneration complete, child objects parsed. [#] Rebuilding complete firmware with injection. ffs size mismatch old=3715000 new=3115389 599611 [#] Rebuild complete, injection successful. Wrote: efi-trojaned.rom [#] Injected firmware written to efi-trojaned.rom. theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_parser.py ./efi64.rom Parsing FV at index (0x0). Firmware Volume: Firmware Volume Blocks: File 0: 1b45cc0a-156a-428a-62af-49864da0e6e6 Section 0: File 1: df1ccef6-f301-4a63-6196-fc6030dcc880 Section 0: Section 1: Name: SecMain Section 2: File 2: ffffffff-ffff-ffff-ffff-ffffffffffff File 3: 52c05b14-0b98-496c-3bbc-04b50211d680 Section 0: Section 1: Section 2: Name: PeiCore Section 3: File 4: ffffffff-ffff-ffff-ffff-ffffffffffff [……] Firmware FileSystem Tiano/EFI Padding Raw apriori file PeiCore SecMain Firmware Volumes { { { Raw UEFI PE32 Name str UEFI PE32 Name Str Raw

Slide 24

Slide 24 text

demo.inspect! theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_injector.py --guid c57ad6b7-0515-40a8-219d-551652854e37 --injection ./evil.efi ./efi64.rom -o efi-trojaned.rom [#] Opening firmware as UEFI firmware volume. Parsing FV at index (volume). [#] Firmware objects parsed. [#] Injecting (replacing) FirmwareFile [#] Regenerating firmware children structures (from injection point). [#] Regeneration complete, child objects parsed. [#] Rebuilding complete firmware with injection. ffs size mismatch old=3715000 new=3115389 599611 [#] Rebuild complete, injection successful. Wrote: efi-trojaned.rom [#] Injected firmware written to efi-trojaned.rom. theo@ubuntu:/mnt/hgfs/Buffers/uefi-research/samples/vmware$ python /mnt/hgfs/git/uefi-firmware-parser/scripts/fv_parser.py ./efi64.rom Parsing FV at index (0x0). Firmware Volume: Firmware Volume Blocks: File 0: 1b45cc0a-156a-428a-62af-49864da0e6e6 Section 0: File 1: df1ccef6-f301-4a63-6196-fc6030dcc880 Section 0: Section 1: Name: SecMain Section 2: File 2: ffffffff-ffff-ffff-ffff-ffffffffffff File 3: 52c05b14-0b98-496c-3bbc-04b50211d680 Section 0: Section 1: Section 2: Name: PeiCore Section 3: File 4: ffffffff-ffff-ffff-ffff-ffffffffffff [……] Inject into an update: !      $  python  fv_injector.py              -­‐-­‐guid  c57ad6b7-­‐0515-­‐40a8-­‐219d-­‐551652854e37              -­‐-­‐injection  ./evil.efi  ./efi64.rom  -­‐o  efi-­‐trojaned.rom

Slide 25

Slide 25 text

What’s in an update? There are tons of wacky code/data embedding examples { { { { Firmware Capsule/ Flash Descriptor Firmware Volumes Firmware FileSystem Tiano/EFI NTFS FAT Padding Raw Firmware File Firmware File Firmware File Encapsulation Firmware File Firmware File Firmware File Depex Exp UEFI PE MORE!?!?! MEbx iAMT Trojans PM Configs Microcode

Slide 26

Slide 26 text

What’s in an update? UEFI PE32 { [IMAGE_OPTIONAL_HEADER64] Magic: 0x20B MajorLinkerVersion: 0x8 MinorLinkerVersion: 0x0 SizeOfCode: 0x800 SizeOfInitializedData: 0xC200 SizeOfUninitializedData: 0x0 AddressOfEntryPoint: 0x1008 BaseOfCode: 0x1000 ImageBase: 0x1000000 SectionAlignment: 0x1000 FileAlignment: 0x200 […] SizeOfImage: 0xF000 SizeOfHeaders: 0x400 CheckSum: 0xFBAF Subsystem: 0xA DllCharacteristics: 0x0 […] LoaderFlags: 0x0 NumberOfRvaAndSizes: 0x10 [IMAGE_SECTION_HEADER] Name: .text Misc: 0x7EC Misc_PhysicalAddress: 0x7EC Misc_VirtualSize: 0x7EC VirtualAddress: 0x1000 SizeOfRawData: 0x800 PointerToRawData: 0x400 [IMAGE_SECTION_HEADER] Name: .data Misc: 0xBF80 Misc_PhysicalAddress: 0xBF80 Misc_VirtualSize: 0xBF80 VirtualAddress: 0x2000 SizeOfRawData: 0xC000 PointerToRawData: 0xC00 [IMAGE_SECTION_HEADER] Name: .reloc Misc: 0xC Misc_PhysicalAddress: 0xC Misc_VirtualSize: 0xC VirtualAddress: 0xE000 SizeOfRawData: 0x200 PointerToRawData: 0xCC00 [IMAGE_FILE_HEADER] Machine: 0x8664 NumberOfSections: 0x3 TimeDateStamp: 0x4B8B66BB [Mon Mar 1 07:03:23 2010 UTC] PointerToSymbolTable: 0x0 NumberOfSymbols: 0x0 SizeOfOptionalHeader: 0xF0 Characteristics: 0x2022 }

Slide 27

Slide 27 text

demo.inspect!, “lame…” There are plenty of tools that patch U/EFI and BIOS updates already, for legitimate purposes https://github.com/NikolajSchlej/PMPatch https://github.com/untermensch/Injector https://github.com/waweber/slicloader https://github.com/NikolajSchlej/UEFITool Hackintosh Pirating Now we have a flexible tool that accomplishes! predefined goals with pervasiveness

Slide 28

Slide 28 text

Overview::reverse() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks

Slide 29

Slide 29 text

Protection Domains 3: Userland 0: Kernel -2: SMM -3: ME Computer Science defines protection domains as rings where the outer rings imply less privilege Mockingly, researchers and hackers define low-level environments as negative rings as they allow higher privilege Scariness = (ring) × -1

Slide 30

Slide 30 text

Protection Domains Traditional and practical cyber defense applied here Network Applications Middleware Security 3: Userland 0: Kernel -2: SMM -3: ME Scariness = (ring) × -1

Slide 31

Slide 31 text

#define Subzero 3: Userland 0: Kernel -2: SMM -3: ME Scariness = (ring) × -1 “Sub” zero rings are the highest privilege

Slide 32

Slide 32 text

#define Subzero And Subzero is a scary dude Image © 1992, 2009 Midway Games

Slide 33

Slide 33 text

Subzero Attack Surface typedef struct { EFI_GUID OemGuid; UINT32 HeaderSize; // // UINT8 OemHdrData[]; // } EFI_CAPSULE_OEM_HEADER; ! typedef struct { EFI_GUID CapsuleGuid; UINT32 HeaderSize; UINT32 Flags; UINT32 CapsuleImageSize; UINT32 SequenceNumber; EFI_GUID InstanceId; UINT32 OffsetToSplitInformation; UINT32 OffsetToCapsuleBody; UINT32 OffsetToOemDefinedHeader; UINT32 OffsetToAuthorInformation; UINT32 OffsetToRevisionInformation; UINT32 OffsetToShortDescription; UINT32 OffsetToLongDescription; UINT32 OffsetToApplicableDevices; } FRAMEWORK_EFI_CAPSULE_HEADER; OEM provided, unsigned data

Slide 34

Slide 34 text

Subzero Attack Surface ISV/OEM provided tools, GUIs, “features” Useless UEFI “games” FTP file browsing SATA/NTFS browsing Within-UEFI non-TLS updates Image parsing (within GUIs) Memory-sensitive APIs OS/User-controlled NVRAM Other network services: UPnP, DHCP, SMB

Slide 35

Slide 35 text

Subzero Attack Surface Misunderstood (by implementers) SecureBoot variables PeiSecurityPpi   __ImageVerificationLib   ! Samsung UEFI bug SecureBootEnable bit SETUP_MODE bit SPI flash write bits

Slide 36

Slide 36 text

Update Analysis #! FORK ME https://github.com/theopolis/subzero Consumes the output JSON from uefi-spider Web-based UI for browsing, inspecting firmware objects Vulnerability hunting platform powered by statistics Several offline Map/Reduce scripts

Slide 37

Slide 37 text

Overview::analyze() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks

Slide 38

Slide 38 text

Subzero Security Patching “1-days from Hell… get it?” 141c142,144 < if ( sub_FFC40CE8(0x60u) != -1 || sub_FFC40CE8(0x64u) != -1 ) --- > sub_FFC40D21(0xCF8u, 0x8000F8DC); > sub_FFC40D0F(0xCFCu, 2u); > if ( sub_FFC40D08(0x60u) != -1 || sub_FFC40D08(0x64u) != -1 ) [update, product, and vendor not shown] “Hell… subzero… hahaha!”

Slide 39

Slide 39 text

Subzero Security Patching “1-days from Hell… get it?” Comparing EIP disassembly is tedious Updates are mostly roll-ups and feature/bug fixes Registers and EFI variable locations are unique [update, product, and vendor not shown] 141c142,144 < if ( sub_FFC40CE8(0x60u) != -1 || sub_FFC40CE8(0x64u) != -1 ) --- > sub_FFC40D21(0xCF8u, 0x8000F8DC); > sub_FFC40D0F(0xCFCu, 2u); > if ( sub_FFC40D08(0x60u) != -1 || sub_FFC40D08(0x64u) != -1 )

Slide 40

Slide 40 text

Subzero Vulnerability Hunting Memory-manipulation UEFI protocol APIs Trusted Computing and secure boot GUIDs Implementation-varied Tiano deviations Variances in updated products Lagged reference implementation rollups Small deltas in update times Updates correlated with security announces Patch notes or criticality labels

Slide 41

Slide 41 text

Subzero Vulnerability Hunting Memory-manipulation! UEFI protocol APIs Trusted Computing and secure boot GUIDs Implementation-varied Tiano deviations Variances in updated products Lagged reference implementation rollups Small deltas in ! update times Updates correlated ! with security announces Patch notes or ! criticality labels

Slide 42

Slide 42 text

Subzero Vulnerability Hunting Memory-manipulation! UEFI protocol APIs From the UEFI Pre-EFI Core Interface Specification: CopyMem() AllocatePool() AllocatePages() SetMem() typedef     VOID     (EFIAPI  *EFI_PEI_COPY_MEM)  (              IN  VOID  *Destination,              IN  VOID  *Source,              IN  UINTN  Length     );    

Slide 43

Slide 43 text

Subzero Vulnerability Hunting Memory-manipulation! UEFI protocol APIs ~/git/edk2$  grep  -­‐rn  “CopyMem  (“  .  |  wc  -­‐l   3454 Disassembly for PEI API “Services” lookup and usage as pseudo-FLIRT signatures Elasticsearch + Disassembly = CopyMem changes

Slide 44

Slide 44 text

Subzero Vulnerability Hunting Small deltas in ! update times ! Dell VNHYR 5s Dell FKWXJ 9s Dell GT9WH 2286s Dell V76CK 10250s Dell 9XPHF 10260s Dell 8CKTP 10688s Dell VHW00 19980s Dell 0MHFX 31003s Dell V49WK 52593s Dell 747D9 57284s MSI 7851v14 86400s HP cp_125425_1 86400s HP cp_102216_1 86400s HP cp_121648_1 86400s MSI 7760v13 172800s MSI 7673v15 172800s MSI 7676vA2 172800s MSI 7681v14 172800s MSI 7846v15 259200s MSI 7673v1D 1 bytes MSI 7673v1E 3 bytes MSI 7759v18 3 bytes MSI 7680v14 465 bytes MSI 7750v31 484 bytes MSI 7676vA2 538 bytes MSI 7751vHA 671 bytes MSI 7788v13 841 bytes MSI 7681vM8 2159 bytes MSI 7681vN6 2159 bytes Dell V89FN 2924 bytes Dell FMGCM 4122 bytes Dell 1RJW0 4122 bytes Dell 6DF38 5870 bytes Dell KCXX0 13787 bytes Dell W8N5N 19927 bytes Dell PKPRV 124304 bytes Dell JX37K 212383 bytes Dell VNHYR 247310 bytes Dell 2GNVV 322353 bytes

Slide 45

Slide 45 text

Subzero Vulnerability Hunting Updates correlated ! with security announces

Slide 46

Slide 46 text

Subzero Vulnerability Hunting Updates correlated ! with security announces

Slide 47

Slide 47 text

Subzero Vulnerability Hunting Updates correlated ! with security announces

Slide 48

Slide 48 text

Subzero Vulnerability Hunting Updates correlated ! with security announces

Slide 49

Slide 49 text

Subzero Vulnerability Hunting Patch notes or ! criticality labels

Slide 50

Slide 50 text

Subzero Vulnerability Hunting Patch notes or ! criticality labels

Slide 51

Slide 51 text

Subzero Vulnerability Hunting Patch notes or ! criticality labels Fixes - Not Applicable. Enhancements - Updated thermal table. - Updated Intel CPU micro code. - Enhanced BIOS Security. - Supported Graphic card M6100.

Slide 52

Slide 52 text

Subzero Vulnerability Hunting Patch notes or ! criticality labels

Slide 53

Slide 53 text

Overview::analyze!() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks

Slide 54

Slide 54 text

Most-used EFI Application

Slide 55

Slide 55 text

Most-used EFI Application

Slide 56

Slide 56 text

Download PE32 & RE

Slide 57

Slide 57 text

autochk_dropper

Slide 58

Slide 58 text

rpcnetp_dropper autochk.exe is running as a Windowsnative mode process (post-kernel) linked to ntdll.dll Before the Win32 subsystem no signing, no obfuscation

Slide 59

Slide 59 text

Dropper Chain (UEFI) DXE Computrace Driver (UEFI) DXE dmidbg64 Application (UEFI) DXE (unpacked) autochk.exe Patcher (WinNative) weaponized autochk.exe (Win32) Backdoor RAT rpcnetp.exe Network C&C Fun… Full Computrace (UEFI) PEI SMM Computrace Driver

Slide 60

Slide 60 text

Dropper Chain (UEFI) DXE Computrace Driver (UEFI) DXE dmidbg64 Application (UEFI) DXE (unpacked) autochk.exe Patcher (WinNative) weaponized autochk.exe (Win32) Backdoor RAT rpcnetp.exe Network C&C Fun… Full Computrace (UEFI) PEI SMM Computrace Driver

Slide 61

Slide 61 text

Hijacking Dropper (UEFI) DXE Computrace Driver (UEFI) DXE dmidbg64 Application (UEFI) DXE (unpacked) autochk.exe Patcher (WinNative) weaponized autochk.exe (Win32) Backdoor RAT rpcnetp.exe Network C&C Fun… Full Computrace (UEFI) PEI SMM Computrace Driver

Slide 62

Slide 62 text

Hijacking Dropper (UEFI) DXE Computrace Driver (UEFI) DXE dmidbg64 Application (UEFI) DXE (unpacked) autochk.exe Patcher (WinNative) weaponized autochk.exe (Win32) Backdoor RAT rpcnetp.exe Network C&C Fun… Full Computrace (UEFI) PEI SMM Computrace Driver

Slide 63

Slide 63 text

Trivial Computrace Takeover

Slide 64

Slide 64 text

Trivial Computrace Takeover

Slide 65

Slide 65 text

Trivial Computrace Takeover

Slide 66

Slide 66 text

Trivial Computrace Takeover

Slide 67

Slide 67 text

Trivial Computrace Takeover

Slide 68

Slide 68 text

Subzero Pentesting WMIC/Powershell to profile platform & BIOS version Database of all updates, match target system’s Inject selected payload as DXE driver and flash Post Exploitation / Subzero Persistance

Slide 69

Slide 69 text

Subzero Pentesting Firmware signing and Secure Boot prevent this hijacking or any other trivial root kit injection But how many systems are signing by default?

Slide 70

Slide 70 text

Overview::_winning() Obtain all the UEFIs Identify vendor- specific implementations Reverse ia32/ x86/am64 UEFI assembly Extract non- signed code portions Inject and modify UEFI code Identify non- signed products Pinpoint potential 1-day vulnerabilities Isolate security related UEFI code changes Inject POST exploit RAT Integrate pentesting frameworks

Slide 71

Slide 71 text

demo.__exit()

Slide 72

Slide 72 text

demo._details() 17.5 Kb payload binary Installed as a Windows 7/8 service with various dependencies Todo: inject larger payloads while maintaining UEFI volumes, files, and capsule integrity Todo: verify product adherence to Secure boot UEFI variables and FileSystemSection attributes

Slide 73

Slide 73 text

Thanks! Questions!? https://github.com/theopolis/subzero https://github.com/theopolis/uefi-spider https://github.com/theopolis/uefi-firmware-parser