def generate_write_at(addr):
res = x86.MultipleInstr()
res += x86.Mov(x86.deref(addr), "EAX")
res += x86.Ret()
return res.get_code()
print("Allocating memory in our calc")
addr = calc.virtual_alloc(0x1000)
print("Allocated memory is at <{0}>".format(hex(addr)))
print("Writing 'SOME STUFF' in allocated memory")
calc.write_memory(addr, "SOME STUFF")
print("Reading allocated memory : <{0}>".format(repr(calc.read_memory(addr, 20))))
# Remote Execution
print("Execution some native code in our calc (write 0x424242 at allocated address + return 0x1337)")
if calc.bitness == 32:
# Let's generate some native code
code = x86.MultipleInstr()
code += x86.Mov(x86.deref(addr), 0x42424242)
code += x86.Mov("EAX", 0x1337)
code += x86.Ret()
else:
code = x64.MultipleInstr()
code += x64.Mov('RAX', addr)
code += x64.Mov(x64.mem("[RAX]"), 0x42424242)
code += x64.Mov("RAX", 0x1337)
code += x64.Ret()
print("Executing native code !")
t = calc.execute(code.get_code())
t.wait()
print("Return code = {0}".format(hex(t.exit_code)))
print("Reading allocated memory : <{0}>".format(repr(calc.read_memory(addr, 20))))
def generate_read_at(addr):
res = x86.MultipleInstr()
res += x86.Mov("EAX", x86.deref(addr))
res += x86.Ret()
return res.get_code()
def trigger(self, dbg, exc):
fault_addr = exc.ExceptionRecord.ExceptionInformation[1]
eip = dbg.current_thread.context.pc
print("Instruction at <{0:#x}> wrote at <{1:#x}>".format(
eip, fault_addr))
dbg.single_step_counter = 4
return dbg.single_step()
calc = windows.test.pop_calc_32(dwCreationFlags=DEBUG_PROCESS)
d = MyDebugger(calc)
code = calc.virtual_alloc(0x1000)
data = calc.virtual_alloc(0x1000)
injected = x86.MultipleInstr()
injected += x86.Mov("EAX", 0)
injected += x86.Mov(x86.deref(data), "EAX")
injected += x86.Add("EAX", 4)
injected += x86.Mov(x86.deref(data + 4), "EAX")
injected += x86.Add("EAX", 8)
injected += x86.Mov(x86.deref(data + 8), "EAX")
injected += x86.Nop()
injected += x86.Nop()
injected += x86.Ret()
calc.write_memory(code, injected.get_code())
d.add_bp(SingleStepOnWrite(data, size=8, events="W"))
calc.create_thread(code, 0)
d.loop()
def trigger(self, dbg, exc):
fault_addr = exc.ExceptionRecord.ExceptionInformation[1]
eip = dbg.current_thread.context.pc
print("Instruction at <{0:#x}> wrote at <{1:#x}>".format(eip, fault_addr))
dbg.single_step_counter = 4
return dbg.single_step()
calc = windows.test.pop_calc_32(dwCreationFlags=DEBUG_PROCESS)
d = MyDebugger(calc)
code = calc.virtual_alloc(0x1000)
data = calc.virtual_alloc(0x1000)
injected = x86.MultipleInstr()
injected += x86.Mov("EAX", 0)
injected += x86.Mov(x86.deref(data), "EAX")
injected += x86.Add("EAX", 4)
injected += x86.Mov(x86.deref(data + 4), "EAX")
injected += x86.Add("EAX", 8)
injected += x86.Mov(x86.deref(data + 8), "EAX")
injected += x86.Nop()
injected += x86.Nop()
injected += x86.Ret()
calc.write_memory(code, injected.get_code())
d.add_bp(SingleStepOnWrite(data, size=8, events="W"))
calc.create_thread(code, 0)
d.loop()
def hook_ntcreatefile(kdbg, ignore_jump_space_check=False):
"""Hook NtCreateFile, the hook write the filename to a shared memory page"""
nt_create_file = kdbg.resolve_symbol("nt!NtCreateFile")
if not ignore_jump_space_check:
# Check that function begin with mov edi, edi for the hook short jump
if kdbg.read_word(nt_create_file) != 0xff8b: # mov edi, edi
print(hex(kdbg.read_word(nt_create_file)))
raise ValueError(
"Cannot hook fonction that doest not begin with <mov edi,edi> (/f to force if hook already in place)"
)
# Check there is 5 bytes free before for the hook long jump
if kdbg.read_virtual_memory(nt_create_file - 5,
5) not in ["\x90" * 5, "\xCC" * 5
]: #NOP * 5 ; INT 3 * 5
print(kdbg.read_virtual_memory(nt_create_file - 5, 5))
raise ValueError(
"Cannot hook fonction that is not prefixed with 5 nop/int 3")
# Allocate memory for the shared buffer kernel<->user
# the format is:
# [addr] -> size of size already taken
# then:
# DWORD string_size
# char[string_size] filename
data_kernel_addr = kdbg.alloc_memory(0x1000)
kdbg.write_pfv_memory(data_kernel_addr, "\x00" * 0x1000)
# Map the shared buffer to userland
data_user_addr = kdbg.map_page_to_userland(data_kernel_addr, 0x1000)
# Allocate memory for the hook
shellcode_addr = kdbg.alloc_memory(0x1000)
# shellcode
shellcode = x86.MultipleInstr()
# Save register
shellcode += x86.Push('EAX')
shellcode += x86.Push('ECX')
shellcode += x86.Push('EDI')
shellcode += x86.Push('ESI')
# Check that there is space remaining, else don't write it
shellcode += x86.Cmp(x86.deref(data_kernel_addr), 0x900)
shellcode += x86.Jnb(":END")
# Get 3rd arg (POBJECT_ATTRIBUTES ObjectAttributes)
shellcode += x86.Mov('EAX', x86.mem('[ESP + 0x1c]')) # 0xc + 0x10 for push
# Get POBJECT_ATTRIBUTES.ObjectName (PUNICODE_STRING)
shellcode += x86.Mov('EAX', x86.mem('[EAX + 0x8]'))
shellcode += x86.Xor('ECX', 'ECX')
# Get PUNICODE_STRING.Length
shellcode += x86.Mov('CX', x86.mem('[EAX + 0]'))
# Get PUNICODE_STRING.Buffer
shellcode += x86.Mov('ESI', x86.mem('[EAX + 4]'))
# Get the next free bytes in shared buffer
shellcode += x86.Mov('EDI', data_kernel_addr + 4)
shellcode += x86.Add('EDI', x86.deref(data_kernel_addr))
# Write (DWORD string_size) in our 'struct'
shellcode += x86.Mov(x86.mem('[EDI]'), 'ECX')
# update size taken in shared buffer
shellcode += x86.Add(x86.deref(data_kernel_addr), 'ECX')
shellcode += x86.Add(x86.deref(data_kernel_addr), 4)
# Write (char[string_size] filename) in our 'struct'
shellcode += x86.Add('EDI', 4)
shellcode += x86.Rep + x86.Movsb()
shellcode += x86.Label(":END")
# Restore buffer
shellcode += x86.Pop('ESI')
shellcode += x86.Pop('EDI')
shellcode += x86.Pop('ECX')
shellcode += x86.Pop('EAX')
# Jump to NtCreateFile
shellcode += x86.JmpAt(nt_create_file + 2)
# Write shellcode
kdbg.write_pfv_memory(shellcode_addr, shellcode.get_code())
long_jump = x86.Jmp(shellcode_addr - (nt_create_file - 5))
# Write longjump to shellcode
kdbg.write_pfv_memory(nt_create_file - 5, long_jump.get_code())
# Write shortjump NtCreateFile -> longjump
short_jmp = x86.Jmp(-5)
kdbg.write_pfv_memory(nt_create_file, short_jmp.get_code())
# Return address of shared buffer in userland
return data_user_addr
def hook_ntcreatefile(kdbg, ignore_jump_space_check=False):
"""Hook NtCreateFile, the hook write the filename to a shared memory page"""
nt_create_file = kdbg.resolve_symbol("nt!NtCreateFile")
if not ignore_jump_space_check:
# Check that function begin with mov edi, edi for the hook short jump
if kdbg.read_word(nt_create_file) != 0xff8b: # mov edi, edi
print(hex(kdbg.read_word(nt_create_file)))
raise ValueError("Cannot hook fonction that doest not begin with <mov edi,edi> (/f to force if hook already in place)")
# Check there is 5 bytes free before for the hook long jump
if kdbg.read_virtual_memory(nt_create_file - 5, 5) not in ["\x90" * 5, "\xCC" * 5]: #NOP * 5 ; INT 3 * 5
print(kdbg.read_virtual_memory(nt_create_file - 5, 5))
raise ValueError("Cannot hook fonction that is not prefixed with 5 nop/int 3")
# Allocate memory for the shared buffer kernel<->user
# the format is:
# [addr] -> size of size already taken
# then:
# DWORD string_size
# char[string_size] filename
data_kernel_addr = kdbg.alloc_memory(0x1000)
kdbg.write_pfv_memory(data_kernel_addr, "\x00" * 0x1000)
# Map the shared buffer to userland
data_user_addr = kdbg.map_page_to_userland(data_kernel_addr, 0x1000)
# Allocate memory for the hook
shellcode_addr = kdbg.alloc_memory(0x1000)
# shellcode
shellcode = x86.MultipleInstr()
# Save register
shellcode += x86.Push('EAX')
shellcode += x86.Push('ECX')
shellcode += x86.Push('EDI')
shellcode += x86.Push('ESI')
# Check that there is space remaining, else don't write it
shellcode += x86.Cmp(x86.deref(data_kernel_addr), 0x900)
shellcode += x86.Jnb(":END")
# Get 3rd arg (POBJECT_ATTRIBUTES ObjectAttributes)
shellcode += x86.Mov('EAX', x86.mem('[ESP + 0x1c]')) # 0xc + 0x10 for push
# Get POBJECT_ATTRIBUTES.ObjectName (PUNICODE_STRING)
shellcode += x86.Mov('EAX', x86.mem('[EAX + 0x8]'))
shellcode += x86.Xor('ECX', 'ECX')
# Get PUNICODE_STRING.Length
shellcode += x86.Mov('CX', x86.mem('[EAX + 0]'))
# Get PUNICODE_STRING.Buffer
shellcode += x86.Mov('ESI', x86.mem('[EAX + 4]'))
# Get the next free bytes in shared buffer
shellcode += x86.Mov('EDI', data_kernel_addr + 4)
shellcode += x86.Add('EDI', x86.deref(data_kernel_addr))
# Write (DWORD string_size) in our 'struct'
shellcode += x86.Mov(x86.mem('[EDI]'), 'ECX')
# update size taken in shared buffer
shellcode += x86.Add(x86.deref(data_kernel_addr), 'ECX')
shellcode += x86.Add(x86.deref(data_kernel_addr), 4)
# Write (char[string_size] filename) in our 'struct'
shellcode += x86.Add('EDI', 4)
shellcode += x86.Rep + x86.Movsb()
shellcode += x86.Label(":END")
# Restore buffer
shellcode += x86.Pop('ESI')
shellcode += x86.Pop('EDI')
shellcode += x86.Pop('ECX')
shellcode += x86.Pop('EAX')
# Jump to NtCreateFile
shellcode += x86.JmpAt(nt_create_file + 2)
# Write shellcode
kdbg.write_pfv_memory(shellcode_addr, shellcode.get_code())
long_jump = x86.Jmp(shellcode_addr - (nt_create_file - 5))
# Write longjump to shellcode
kdbg.write_pfv_memory(nt_create_file - 5, long_jump.get_code())
# Write shortjump NtCreateFile -> longjump
short_jmp = x86.Jmp(-5)
kdbg.write_pfv_memory(nt_create_file, short_jmp.get_code())
# Return address of shared buffer in userland
return data_user_addr
print("Allocating memory in our notepad")
addr = notepad.virtual_alloc(0x1000)
print("Allocated memory is at <{0}>".format(hex(addr)))
print("Writing 'SOME STUFF' in allocated memory")
notepad.write_memory(addr, "SOME STUFF")
print("Reading allocated memory : <{0}>".format(repr(notepad.read_memory(addr, 20))))
# Remote Execution
print("Execution some native code in our notepad (write 0x424242 at allocated address + return 0x1337)")
if notepad.bitness == 32:
# Let's generate some native code
code = x86.MultipleInstr()
code += x86.Mov(x86.deref(addr), 0x42424242)
code += x86.Mov("EAX", 0x1337)
code += x86.Ret()
else:
code = x64.MultipleInstr()
code += x64.Mov('RAX', addr)
code += x64.Mov(x64.mem("[RAX]"), 0x42424242)
code += x64.Mov("RAX", 0x1337)
code += x64.Ret()
print("Executing native code !")
t = notepad.execute(code.get_code())
t.wait()
print("Return code = {0}".format(hex(t.exit_code)))
print("Reading allocated memory : <{0}>".format(repr(notepad.read_memory(addr, 20))))
