LogoLogo
IDA 8.4
IDA 8.4
  • Welcome to Hex-Rays docs
  • User Guide
    • User Interface
      • Menu Bar
        • File
          • Load file
          • Script File
          • Script command
          • Produce output files
          • Invoke OS Shell
          • Take database snapshot
          • Save database
          • Save database as...
          • Abort IDA
          • Exit IDA
        • Edit
          • Export data
          • Undo an action
          • Redo an action
          • Clear undo history
          • Disable undo
          • Convert to instruction
          • Convert to data
          • Convert to string literal
          • Convert to array
          • Undefine a byte
          • Give Name to the Location
          • Operand types
            • Offset
            • Number
            • Perform en masse operation
            • Convert operand to character
            • Convert operand to segment
            • Complex Offset Expression
            • Convert operand to symbolic constant (enum)
            • Convert operand to stack variable
            • Change operand sign
            • Bitwise negate operand
            • User-defined operand
            • Set operand type
          • Comments
          • Functions
          • Structures
            • Enums
          • Segments
          • Patch core
          • Other
            • Rename Any Address
          • Plugins
        • Jump
          • Center current line in window
          • Problems List
        • Search
          • REGULAR EXPRESSION SYNTAX SUMMARY
        • View
          • Open subviews
          • Graphs
          • Message Window
          • Arrows window
          • Database snapshot manager
          • Highlighting identifiers
          • Browser options
          • Lumina options
          • Assembler level and C level types
          • C++ type details
          • Bookmarks window
          • Calculator
          • View segment registers
          • View Internal Flags
          • Hide
          • Unhide
          • Del hidden range
          • Hide all items
          • Unhide all items
          • Setup hidden items
        • Debugger
          • Debugger window
          • Process Control
            • Start process
            • Process options
            • Pause process
            • Terminate process
            • Step into
            • Step over
            • Run to cursor
            • Run until return
            • Attach to process
            • Detach from process
            • Set current ip
            • Show application screen
          • Breakpoints
          • Watches
          • Tracing
          • Source code view
            • Watch view (source level)
          • Process Memory
            • Take memory snapshot
            • Manual memory regions
            • Refresh memory
          • Thread list
          • Module list
          • Stack trace
          • Exceptions
          • Debugger options
          • Switch debugger
        • Lumina
        • Options
          • Low & High Suspicious Operand Limits
        • Windows
          • Rename a stack variable
          • Miscellanous Options
          • Environment variables
          • Reset Hidden Messages
          • Various dialog help messages
        • List of all menu options
      • Desktops
      • Command line
      • How To Use List Viewers in IDA
      • Licenses
        • Apache License for Ghidra
        • Apache License for LLVM
        • Common Public License Version 1.0
        • APPLE PUBLIC SOURCE LICENSE
        • PCRE2 LICENCE
        • GNU Lesser General Public License v2.1 for libiberty
      • Database conversion from idb to i64
    • Disassembler
      • Interactivity
      • Background Analysis
      • Graph view
        • Graphing tutorial
      • Proximity view
      • Navigation
        • Anchor
        • How to Enter a Segment Value
        • How to Enter a Number
        • How to Enter an Identifier
        • How to enter text
        • How to Enter an Address
      • Disassembly Gallery
        • Philips 51XA-G3
        • 6502 and 65C02 Disassembler
        • 6301, 6303, 6800, 6801 and 6803 Disassembler
        • 68040, Amiga
        • 6805 Disassembler
        • 6808 Disassembler
        • 6809 OS9 Flex Disassembler
        • 6809 Disassembler
        • 6811 Disassembler
        • 68HC12 Disassembler
        • 68HC16 Disassembler
        • 68k Amiga Disassembler
        • 68k Mac OS
        • 68k Palm Pilot
        • Unix COFF
        • NEC 78k0 and 78k0s Processor
        • 80196 Processor
        • 8051 Disassembler
        • Analog Devices 218x.
        • Alpha Processor – NT COFF
        • Alpha Processor – Unix ELF
        • Android ARM Executables (.elf)
        • ARC Processor
        • ARM Processor EPOC App
        • ARM Processor EPOC PE File
        • ARM Processor EPOC ROMFile
        • EPOC SIS File Handler
        • ARM Processor iOS (iPhone): Unlock
        • ARM Processor iOS (iPhone): Objective-C metadata
        • ARM Processor iOS (iPhone): Objective-C Instance variables
        • ARM Processor iOS (iPhone): Parameter Identification & Tracking (PIT)
        • ARM Processor iOS (iPhone): Start
        • ARM Processor iOS (iPhone): Switch statements
        • ARM Processor iOS (iPhone): C++ signatures
        • ARM Processor iOS (iPhone): Write
        • ARM Processor: Linux ELF
        • ARM Processor: AOF SDK
        • ARM Processor: Windows CE COFF Format
        • ARM Processor: Windows CE PE Format
        • ATMEL AVR Disassembler
        • C166 Processor
        • C166 Processor with ELF file
        • Rockwell C39
        • Microsoft .NET CLI Disassembler. VisualBasic library
        • CR16
        • Android Dalvik Executables (.dex)
        • Microsoft .NET CLI Disassembler
        • DSP56K
        • Fujitsu FR (.elf)
        • Gameboy
        • H8 300: COFF FILE Format
        • H8 300s: COFF FILE Format
        • H8 500
        • HPPA Risc Processor: HP-UX SOM
        • i51
        • i860
        • Intel i960
        • Intel IA-64 (Itanium)
        • Java Bytecode
        • Angstrem KR 1878
        • Renesas/Hitachi M16C
        • Renesas/Hitachi M32R
        • M740
        • M7700
        • M7900
        • MIPS Processor: Nintendo N64
        • MIPS R5900 Processor : Sony bin
        • MIPS Processor: Sony ELF
        • MIPS Processor: Sony PSX
        • MIPS Processor: Sony PSX
        • MIPS Processor: Unix COFF File Format
        • MIPS Processor: Unix ELF File Format
        • MIPS Processor: Windows CE PE File Format
        • MIPS Processor: Windows CE PE2 File Format
        • Panasonic MN102
        • Atmel OAK DSP
        • 80×86 Architecture: DOS Extender
        • 80×86 Architecture: Watcom Runtime
        • 80×86 Architecture: Geos APP
        • 80×86 Architecture: Geos DRV
        • 80×86 Architecture: Geos LIB
        • 80×86 Architecture: GNU COFF Format
        • 80×86 Architecture: OS/2 Linear Executable Format
        • 80×86 Architecture: Netware NLM
        • 80×86 Architecture: QNX Executable
        • 80×86 Architecture: Watcom Runtime
        • 80×86 Architecture: Windows OMF
        • 80×86 Architecture: Windows Portable Executable Format
        • 80×86 Architecture: Windows Virtual Device Driver
        • 80×86 Architecture: Windows 16 bits DLL
        • X-Box Disassembler
        • PDP 11: SAV File
        • PIC
        • PIC 12xx
        • Power PC AIF ECOFF file Format
        • Power PC Linux ELF
        • Mac OS PEF File
        • Mac OS X File
        • Windows NT PE File
        • Hitachi SH-1 Processor
        • Hitachi SH-3 Processor: Windows CE COFF format
        • Hitachi SH-3 Processor: Windows CE PE format
        • Hitachi SH-4 Processor: ELF File Format
        • Hitachi SH-4 Processor: Windows CE PE File Format
        • Super Nintendo Entertainement System (SNES)
        • SPARC Solaris COFF
        • SPARC Solaris ELF
        • SPARC Sun ELF
        • SPARC Sun ELF SO
        • ST 20C4
        • ST 7
        • ST 9
        • Toshiba TLCS 900
        • TMS 320c2 COFF
        • TMS 320c5
        • TMS 320c54
        • TMS 320c6 COFF File Format
        • TRICORE
        • SunPlus unSP
        • NEC V850
        • Z180 COFF File Format
        • Z380 COFF File Format
        • Z8
        • Z80
      • Supported processors
      • Supported file formats
        • Windmp file loader
      • Bitfields
        • Bit Fields tutorial
      • Structures tutorial
      • Union tutorial
      • Variable length structures tutorial
      • Data types, operands and constructs
      • Packed executables
    • Decompiler
      • Prerequisites
      • Quick primer
      • Exception handler
      • Introduction to Decompilation vs. Disassembly
        • Comparisons of ARM disassembly and decompilation
        • Comparisons of PowerPC disassembly and decompilation
        • Comparisons of MIPS disassembly and decompilation
        • Hex-Rays v7.4 vs. v7.3 Decompiler Comparison Page
        • Hex-Rays v7.3 vs. v7.2 Decompiler Comparison Page
        • Hex-Rays v7.2 vs. v7.1 Decompiler Comparison Page
      • Interactive operation
        • Rename
        • Set type
        • Set number representation
        • Edit indented comment
        • Edit block comment
        • Hide/unhide C statements
        • Split/unsplit expression
        • Force call type
        • Set call type
        • Add/del variadic arguments
        • Del function argument
        • Add/delete function return type
        • Jump to cross reference
        • Jump to cross reference globally
        • Generate HTML file
        • Mark/unmark as decompiled
        • Copy to assembly
        • Show/hide casts
        • Reset pointer type
        • Convert to struct *
        • Create new struct type
        • Split variable
        • Select union field
        • Jump to paired paren
        • Collapse/uncollapse item
        • Map to another variable
      • Batch operation
      • Configuration
      • Third party plugins
      • Floating point support
      • Support for intrinsic functions
      • Overlapped variables
      • gooMBA
      • Failures and troubleshooting
      • FAQ
      • Limitations
      • Tips and tricks
    • Debugger
      • Instant debugger
      • Remote debugging
        • Remote iOS Debugger
        • Android debugger
        • Dalvik debugger
        • Remote GDB Debugger
          • Remote GDB Debugger options
          • Debugging with gdbserver
          • Debugging with VMWare
          • Debugging with OpenOCD
          • Debugging with QEMU
          • External programs and GDB Debugger
          • Debugging code snippets with QEMU
        • PIN debugger
          • Building the PIN tool
          • Connecting a remote PIN tool instance from IDA
          • PIN support for MacOSX
        • Replayer debugger
        • Bochs debugger
          • Bochs Disk Image operation mode
          • Bochs IDB operation mode
          • Bochs PE operation mode
          • Bochs debugger FAQ
      • Local debugging
        • WinDbg Debugger
        • Linux debugger
        • Intel/ARM macOS debugger
      • Debugger tutorials
        • Debugging Dalvik Programs
        • IDA Win32 Local Debugging
        • IDA Linux Local Debugging
        • IDA Win32 to Win32 Debugging
        • IDA Win32 to Win64 Debugging
        • Debugging Mac OSX Applications with IDA Pro
        • Debugging iOS Applications with IDA Pro
        • Debugging Linux Applications locally
        • Debugging Linux/Windows Applications with PIN Tracer module
        • Debugging Windows Applications with IDA Bochs Plugin
        • Debugging Windows Applications with IDA WinDbg Plugin
        • Using the Bochs debugger plugin in Linux
        • Debugging Windows Kernel with VMWare and IDA WinDbg Plugin
        • Debugging Linux Kernel under VMWare using IDA GDB debugger
        • Windows Debugger Hub
        • Linux Debugger
        • Debugging a Windows executable locally and remotely
        • Debugging the XNU Kernel with IDA Pro
        • Remote debugging with IDA Pro
        • IDA Scriptable Debugger: overview
          • IDA Scriptable Debugger: scriptability
        • Debugging code snippets with QEMU debugger (a la IDA Bochs debugger)
        • Trace Replayer and managing traces
        • Using IDA Pro's tracing features
        • Working with PIN
        • Appcall
    • Signatures
      • FLIRT
        • IDA F.L.I.R.T. Technology: In-Depth
        • Supported Compilers
          • Turbo Pascal
          • Delphi
      • Makesig
    • Type Libraries
      • IDAClang
      • TILIB
    • Configuration
      • Configuration files
      • Command line switches
      • Keyboard macros
    • Teams
      • IDA Teams Licenses
      • Diffing and Merging Databases with IDA Teams
      • Teams lc command reference manual
      • hv command reference manual
      • Hex-Rays Vault’s visual client user manual
    • Lumina
      • lc command reference manual
    • Plugins
      • Open Plugin Architecture
      • Plugin options
      • Plugins Shipped with IDA
        • Swift plugin
        • Golang plugin
        • Rust plugin
        • picture_search
        • Objective-C Analysis Plugin
        • DYLD Shared Cache Utils
      • Plugin Contest
      • How to write your own plugin?
    • Helper Tools
  • Developer Guide
    • C++ SDK
      • C++ SDK reference
      • Using the Decompiler SDK: Decompiler Plug-In
    • IDAPython
      • IDAPython API Reference
    • IDC
      • Core concepts
        • Expressions
        • Statements
        • Functions
        • Variables
        • Constants
        • Exceptions
        • Classes
        • Predefined symbols
        • loader_input_t class
        • Slices
      • IDC API Reference
        • Index of debugger related IDC functions
        • Alphabetical list of IDC functions
          • set_selector
          • enable_tracing
          • get_prev_fixup_ea
          • del_segm
          • get_bmask_cmt
          • end_type_updating
          • Find
          • toggle_bnot
          • patch_byte
          • get_module_info
          • set_member_name
          • create_float
          • del_struc_member
          • read_dbg_memory
          • get_enum_width
          • getn_thread_name
          • del_struc
          • filelength
          • set_manual_insn
          • is_value...() functions
          • get_ip_val
          • del_extra_cmt
          • create_insn
          • op_offset_high16
          • get_cmt
          • expand_struc
          • get_idb_path
          • set_frame_size
          • get_file_ext
          • has_value
          • readshort
          • sanitize_file_name
          • get_member_flag
          • create_struct
          • ARM specific
          • Disk Write Error
          • set_enum_member_cmt
          • rename
          • set_ida_state
          • get_member_size
          • msg
          • qbasename
          • get_enum_member_enum
          • auto_mark_range
          • plan_to_apply_idasgn
          • set_named_type
          • op_offset
          • rename_entry
          • strlen
          • get_extra_cmt
          • get_enum_flag
          • fgetc
          • Internal Error
          • op_stkvar
          • get_last_index
          • get_field_ea
          • get_last_struc_idx
          • How to use the help subsystem
          • get_struc_id
          • select_thread
          • create_array
          • get_struc_cmt
          • set_array_string
          • set_func_attr
          • set_storage_type
          • get_struc_size
          • demangle_name
          • get_next_fixup_ea
          • get_next_bmask
          • delattr
          • gen_simple_call_chart
          • patch_qword
          • get_enum_name
          • loader_input_t.getc
          • get_first_struc_idx
          • get_debugger_event_cond
          • read_dbg_qword
          • define_local_var
          • generate_disasm_line
          • add_idc_hotkey
          • tolower
          • del_selector
          • set_debugger_event_cond
          • get_imagebase
          • gen_file
          • get_entry
          • find_custom_data_format
          • get_debug_name_ea
          • add_default_til
          • set_func_end
          • exit_process
          • delete_array
          • xtol
          • get_exception_code
          • detach_process
          • set_enum_cmt
          • get_wide_word
          • put_bookmark
          • is_loaded
          • add_enum_member
          • parse_decls
          • readstr
          • get_entry_qty
          • ord
          • sprintf
          • get_root_filename
          • get_enum_member_cmt
          • create_word
          • set_func_flags
          • loader_input_t.tell
          • create_align
          • read_dbg_dword
          • get_struc_idx
          • next_addr
          • get_bytes
          • batch
          • start_process
          • Cannot Create File
          • process_config_line
          • del_user_info
          • qmakefile
          • set_struc_name
          • print_decls
          • create_custom_data
          • del_enum_member
          • format_cdata
          • get_fixup_target_sel
          • get_item_size
          • loader_input_t.gets
          • get_last_bmask
          • Step Tracing Options
          • get_enum_idx
          • selector_by_name
          • Already recording a macro for...
          • get_enum_cmt
          • next_not_tail
          • prev_head
          • set_color
          • set_numbered_type
          • get_member_name
          • auto_wait
          • get_enum_member_bmask
          • fseek
          • get_segm_start
          • attach_process
          • Trace file functions
          • get_enum_member_value
          • op_stroff
          • get_next_offset
          • set_processor_type
          • get_bookmark_desc
          • Entering String for Search
          • create_data
          • lastattr
          • get_operand_value
          • collect_stack_trace
          • toupper
          • get_fixup_target_dis
          • set_cmt
          • add_entry
          • set_segm_addressing
          • qmake_full_path
          • get_source_linnum
          • fputc
          • resume_thread
          • get_func_attr
          • get_first_enum_member
          • add_sourcefile
          • get_first_bmask
          • read_selection_start
          • hasattr
          • get_member_cmt
          • gen_flow_graph
          • get_array_element
          • get_tinfo
          • loader_input_t
          • tinfo_errstr
          • TRUNC
          • add_segm_ex
          • Not enough memory available to complete operation.
          • Local types information and manipulation helpers
          • set_source_linnum
          • get_next_enum_member
          • loader_input_t.readbytes
          • set_array_params
          • jumpto
          • get_bookmark
          • set_enum_bf
          • prev_not_tail
          • toggle_sign
          • loader_input_t.size
          • Trace events functions
          • get_func_flags
          • get_gotea
          • Bad BIOS & DOS Comments Base
          • set_segm_attr
          • get_item_head
          • set_default_sreg_value
          • print_insn_mnem
          • set_member_cmt
          • get_ordinal_qty
          • set_target_assembler
          • add_user_stkpnt
          • set_local_type
          • Hidden ranges
          • del_items
          • compile_idc_text
          • Dalvik debugger extension functions
          • byte_value
          • create_dword
          • is_code
          • del_func
          • get_enum
          • make_array
          • rotate_left
          • recalc_spd
          • search_path
          • CommonBits
          • get_processor_name
          • set_func_cmt
          • get_prev_bmask
          • Hashes
          • split_sreg_range
          • process_ui_action
          • set_fixup
          • get_fixup_target_type
          • create_oword
          • get_flags
          • get_func_name
          • create_strlit
          • add_struc
          • atol
          • load_debugger
          • mkdir
          • set_struc_idx
          • sizeof
          • get_enum_member_by_name
          • save_database
          • guess_type
          • get_segm_name
          • print_operand
          • qisabspath
          • get_member_qty
          • set_struc_cmt
          • get_fixup_target_flags
          • idadir
          • object.retrieve
          • add_auto_stkpnt
          • get_numbered_type_name
          • get_enum_member_name
          • get_next_index
          • prev_addr
          • get_name_ea
          • get_sp_delta
          • set_bmask_cmt
          • get_struc_qty
          • readlong
          • set_segm_name
          • get_prev_offset
          • set_segm_alignment
          • get_strlit_contents
          • forget_exception
          • get_item_end
          • add_func
          • get_name
          • Asks
          • get_spd
          • Debugger: control
          • get_wide_byte
          • plan_and_wait
          • set_enum_flag
          • RunPythonStatement
          • del_sourcefile
          • get_prev_struc_idx
          • find_selector
          • get_frame_regs_size
          • op_num
          • define_exception
          • create_double
          • create_byte
          • read_selection_end
          • Disk Positioning Error
          • OpTypes
          • op_plain_offset
          • move_segm
          • get_member_id
          • set_segm_combination
          • get_current_thread
          • trim
          • Debugger: options
          • getn_thread
          • get_frame_id
          • typeinfo.print
          • to_ea
          • rebase_program
          • add_struc_member
          • get_exception_qty
          • get_first_index
          • import_type
          • set_segm_type
          • find_custom_data_type
          • get_next_seg
          • find_func_end
          • get_next_struc_idx
          • get_last_enum_member
          • getattr
          • get_frame_size
          • get_screen_ea
          • loader_input_t.read
          • Bad Macro
          • set_reg_value
          • Debugger: modules
          • create_pack_real
          • writestr
          • exec_idc
          • get_enum_size
          • set_enum_name
          • create_tbyte
          • sel2para
          • atoa
          • loader_input_t.close
          • add_enum
          • ltoa
          • set_enum_idx
          • substr
          • del_idc_hotkey
          • Breakpoint handling functions
          • loader_input_t.seek
          • cleanup_appcall
          • object.store
          • get_type
          • qexit
          • get_debug_name
          • get_array_id
          • Can't Open File
          • suspend_process
          • process_config_directive
          • get_entry_name
          • get_last_member
          • get_struc_name
          • clear_selection
          • fclose
          • firstattr
          • How to move/resize windows
          • create_yword
          • dbg_appcall
          • get_qword
          • patch_dword
          • begin_type_updating
          • read_dbg_byte
          • get_fpnum
          • qsleep
          • get_first_member
          • get_nsec_stamp
          • del_stkpnt
          • eval
          • savefile
          • eval_python
          • Xrefs
          • strstr
          • writeshort
          • get_sreg
          • get_segm_end
          • get_func_off_str
          • set_func_start
          • del_array_element
          • get_full_flags
          • set_exception_flags
          • rename_array
          • get_frame_args_size
          • op_flt
          • get_min_spd_ea
          • apply_type
          • get_prev_index
          • loadfile
          • retrieve_input_file_md5
          • get_wide_dword
          • patch_dbg_byte
          • Functions provided by the WinDbg debugger
          • get_original_byte
          • get_member_strid
          • call_system
          • writelong
          • get_thread_qty
          • nextattr
          • send_dbg_command
          • get_first_seg
          • get_processes
          • patch_word
          • get_manual_insn
          • ftell
          • get_entry_ordinal
          • set_array_long
          • delete_all_segments
          • TO_LONG
          • Function chunk related functions
          • Debugger: events
          • get_prev_func
          • op_seg
          • validate_idb_names
          • fprintf
          • fopen
          • strfill
          • del_fixup
          • get_bmask_name
          • Disk Read Error
          • inf_attr
          • is_bf
          • read_dbg_word
          • qdirname
          • get_segm_attr
          • func_contains
          • get_enum_qty
          • del_source_linnum
          • get_sourcefile
          • clr_database_flag
          • bTree Error
          • set_name
          • Refresh Screen
          • op_enum
          • getn_enum
          • get_db_byte
          • setattr
          • get_forced_operand
          • op_bin
          • Functions provided by the replayer debugger
          • prevattr
          • update_extra_cmt
          • get_str_type
          • op_man
          • choose_func
          • set_bmask_name
          • get_curline
          • decode_insn
          • set_segment_bounds
          • get_struc_by_idx
          • set_segm_class
          • write_dbg_memory
          • get_exception_name
          • get_enum_member
          • is_mapped
          • del_enum
          • get_frame_lvar_size
          • get_operand_type
          • set_root_filename
          • compile_idc_file
          • typeinfo.size
          • get_local_tinfo
          • get_fixup_target_off
          • is_union
          • unlink
          • get_segm_by_sel
          • set_enum_width
          • take_memory_snapshot
          • exec_python
          • get_next_func
          • get_member_offset
          • get_func_cmt
          • parse_decl
          • create_qword
          • next_head
          • suspend_thread
          • loader_input_t.getz
          • get_color
          • get_reg_value
          • load_and_run_plugin
          • set_database_flag
          • set_enum_member_name
          • set_member_type
          • get_prev_enum_member
      • IDC examples
        • Batch analysis
        • Device driver analysis
        • New file format definition
        • Structures manipulation
        • VxD analysis
        • Analyzing encrypted code
  • Admin Guide
    • Lumina server
    • Teams server
    • License server
      • Installing on Windows
      • Installing on Linux
      • Installing on OS X
Powered by GitBook
LogoLogo

Need Help?

  • FAQs
  • Support

Community

  • Forum
  • Plugins

Resources

  • Blog
  • Download center

© 2025 Copyright Hex-Rays

On this page
  • Introduction
  • Target
  • Loading binary files into IDA
  • Configuring QEMU
  • Executing the code
  • Saving results to database

Was this helpful?

Export as PDF
  1. User Guide
  2. Debugger
  3. Debugger tutorials

Debugging code snippets with QEMU debugger (a la IDA Bochs debugger)

Last updated 6 months ago

Was this helpful?

Introduction

IDA Pro 5.6 has a new feature: automatic running of the QEMU emulator. It can be used to debug small code snippets directly from the database. In this tutorial we will show how to dynamically run code that can be difficult to analyze statically.

Target

As an example we will use shellcode from the article in Phrack 66. It is self-modifying and because of alphanumeric limitation can be quite hard to undestand. So we will use the debugging feature to decode it.

The sample code is at the bottom of the article but here it is repeated:

80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR80AR 80AR80AR80AR80AR80AR80AR80AR80AR80AR00OB00OR00SU00SE9PSB9PSR0pMB80SBcACP daDPqAGYyPDReaOPeaFPeaFPeaFPeaFPeaFPeaFPd0FU803R9pCRPP7R0P5BcPFE6PCBePFE BP3BlP5RYPFUVP3RAP5RWPFUXpFUx0GRcaFPaP7RAP5BIPFE8p4B0PMRGA5X9pWRAAAO8P4B gaOP000QxFd0i8QCa129ATQC61BTQC0119OBQCA169OCQCa02800271execme22727

Copy this text to a new text file, remove all line breaks (i.e. make it a single long line) and save. Then load it into IDA.

Loading binary files into IDA

IDA displays the following dialog when it doesn't recognize the file format (as in this case):

Since we know that the code is for ARM processor, choose ARM in the "Processor type" dropdown and click Set. Then click OK. The following dialog appears:

When you analyze a real firmware dumped from address 0, these settings are good. However, since our shellcode is not address-dependent, we can choose any address. For example, enter 0x10000 in "ROM start address" and "Loading address" fields.

IDA doesn't know anything about this file so it didn't create any code. Press C to start disassembly.

Configuring QEMU

Before starting debug session, we need to set up automatic running of QEMU.

  1. Edit cfg/gdb_arch.cfg and change "set QEMUPATH" line to point to the directory where you unpacked QEMU. Change "set QEMUFLAGS" if you're using an older version.

  2. In IDA, go to Debug-Debugger options..., Set specific options.

  3. Enable "Run a program before starting debugging".

  4. Click "Choose a configuration". Choose Versatile or Integrator board. The command line and Initial SP fields will be filled in.

  5. Memory map will be filled from the config file too. You can edit it by clicking the "Memory map" button, or from the Debugger-Manual memory regions menu item. See below for more details

Now on every start of debugging session QEMU will be started automatically.

Executing the code

By default, initial execution point is the entry point of the database. If you want to execute some other part of it, there are two ways:

  1. Select the code range that you want to execute, or

  2. Rename starting point ENTRY and ending point EXIT (convention similar to Bochs debugger)

In our case we do want to start at the entry point so we don't need to do anything. If you press F9 now, IDA will write the database contents to an ELF file (database.elfimg) and start QEMU, passing the ELF file name as the "kernel" parameter. QEMU will load it, and stop at the initial point.

Now you can step through the code and inspect what it does. Most of the instructions "just work", however, there is a syscall at 0x0010118:

ROM:00010118 SVCMI 0x414141

Since the QEMU configuration we use is "bare metal", without any operating system, this syscall won't be handled. So we need to skip it.

  1. Navigate to 010118 and press F4 (Run to cursor). Notice that the code was changed (patched by preceding instructions):

  2. Right-click next line (0001011C) and choose Set IP.

  3. Press F7 three times. Once you're on BXPL R6 line, IDA will detect the mode switch and add a change point to Thumb code:

  4. Go to 01012C and press U (Undefine).

  5. Press Alt-G (Change Segment Register Value) and set value of T to 1. The erroneous CODE32 will disappear.

  6. Go back to 00010128 and press C (Make code). Nice Thumb code will appear:

  7. In Thumb code, there is another syscall at 00010152. If you trace or run until it, you can see that R7 becomes 0xB (sys_execve) and R0 points to 00010156.

Hint: if the code you're investigating has many syscalls and you don't want to handle them one by one, put a breakpoint at the address 0000000C (ARM's vector for syscalls). Return address will be in LR.

Saving results to database

If you want to keep the modified code or data for later analysis, you'll need to copy it to the database. For that:

  1. Edit segment attributes (Alt-S) and make sure that segments with the data you need have the "Loader segment" attribute set.

  2. Choose Debugger-Take memory snapshot and answer "Loader segments".

  3. Now you can stop the debugging and inspect the new data. Note: this will update your database with the new data and discard the old. Repeated execution probably will not be correct.

Download a recent version of QEMU with ARM support (e.g. from ). If qemu-system-arm.exe is in a subdirectory, move it next to qemu.exe and all DLLs. Note: if you're running Windows 7 or Vista, it's recommended to use QEMU 0.11 or 0.10.50 ("Snapshot" on Takeda Toshiya's page), as the older versions listen for GDB connections only over IPv6 and IDA can't connect to it.

Happy debugging! Please send any comments or questions to

http://homepage3.nifty.com/takeda-toshiya/qemu/index.html
support@hex-rays.com
"Alphanumeric RISC ARM Shellcode"