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obfu_patches.py
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# This Python file uses the following encoding: utf-8
import re
import idc
from idc import *
import itertools as it
from obfu_handler import PatternMatchingRule
if not idc:
from bitwise import BitwiseMask
from di import diInsns, my_decode_insn, de
from obfu_helpers import kassemble, ObfuFailure, bitsize_signed_2, hex_pattern
from sftools import dinjasm, MyGetOperandDisplacement
from slowtrace_helpers import GetInsnLen
from start import isInt
FLAG_LOCK = 1<<0
FLAG_REPNZ = 1<<1
FLAG_REP = 1<<2
FLAG_HINT_TAKEN = 1<<3
FLAG_HINT_NOT_TAKEN = 1<<4
FLAG_IMM_SIGNED = 1<<5
FLAG_DST_WR = 1<<6
FLAG_RIP_RELATIVE = 1<<7
FLAG_MASK = (1<<8) - 1
# mark_sp_factory('lea_rbp_rsp_x'))
# , [], set_sp_factory('lea_rbp_rsp_x'))
patchmarks = globals().get('patchmarks', dict())
def patch_stack_align(_search, replace, original, ea, addressList, patternComment, addressListWithNops, addressListFull, context, **kwargs):
# this can't work because it's not being passed the latest instruction
# circular list, and even if it were, it would still not contain
# yet-to-be-parsed instructions required for completion
# if context and 'slvars2' in context and 'instructions' in context['slvars2']:
# sti = context['slvars2']['instructions']
#
# m = sti.multimatch([
# # r'({push}push.*)**',
# # r'lea rsp, .*',
# # r'(movupd .*)**',
# # r'push 0x10',
# # r'call ({call}.*)',
# # r'(lea|add) rsp, .*',
# # r'(movupd .*)**',
# # r'lea rsp, \[rsp\+({rspdiff}[^\]]+)\]',
# # r'(pop.*)**',
# # r'({extra}.*)',
# r'({push}push.*)**',
# r'lea rsp, .*',
# r'(movupd .*)**',
# r'push 0x10',
# r'call ({call}.*)',
# r'(lea|add) rsp, .*',
# r'(movupd .*)**',
# r'lea rsp, \[rsp\+({rspdiff}[^\]]+)\]',
# r'(pop.*)**',
# r'({extra}.*)',
# ], groupiter=lambda o: o, gettext=lambda o: o.insn, predicate=lambda o: not o.insn.startswith('jmp'))
#
# if m:
# printi(pfh(m))
# if 'extra' in m and 'push' in m:
# if len(m.push) > 8 and len(m.extra) == 1 and m.extra[0] == 'retn':
# printi("[patch_stack_align] assembling at {:x}".format(m.push[0].ea))
# nassemble(m.push[0].ea,
# """
# push rbp
# mov rbp, rsp
# sub rsp, 32
# {}
# leave
# ret
# """.format(m.call[0]), apply=1)
# else:
# printi("[patch_stack_align] len(push) or len(extra) wrong")
# else:
# printi("[patch_stack_align] extra or push not in m")
# return []
#
# else:
# printi("[patch_stack_align] multimatch didn't")
# printi(pfh(sti))
# setglobal('osti', sti)
#
# else:
# printi("[patch_stack_align] no context.slvars2.instructions")
return ["push 0x10", diida(addressList[21+3]), "add rsp, 8"]
def simple_patch_factory(s):
"""
simple_patch_factory("push qword [{idc.get_name(idc.get_operand_value(addressList[1], 1))}]")
would create a patch to evaluate and replace: {idc.get_name(idc.get_operand_value(addressList[1], 1))}
"""
# regex = re.compile(r'\{([^}]+)\}')
regex = r'\{([^}]+)\}'
# replace=replaceFunction(search, replace, original, ea, addressList, patternComment)
def patch( search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
def terp(m):
return eval(m.group(1), globals(), {'addressList': addressList})
def interpolate_inner(s):
return re.sub(regex, terp, s)
if isinstance(s, list):
result = [interpolate_inner(x) for x in s]
else:
result = interpolate_inner(s)
# dprint("[simple_patch_factory] result")
if obfu_debug: printi("[simple_patch_factory] result:{}".format(result))
return list(result)
# is this causing the results to be totally nopped sometimes? probably
# not, but lets see if it makes a difference to do it the above way
return (len(search), list(result))
return patch
def mark_sp_factory(mark):
"""
Typical Input:
028 -250 48 81 ec 50 02 00 00 sub rsp, 0x250 ; won't be passed as input
278 [48 8d 6c 24 20] lea rbp, [rsp+0x20]
.....................................................
48 8d a5 30 02 00 00 lea rsp, [rbp+0x230] ; will be passed as set_sp_factory input
Another Example:
.text:1433bb21d 68 4c 8d 5c 24 40 lea r11, [rsp+0x40]
.text:1433bb222 68 49 8b 5b 30 mov rbx, [r11+0x30]
.text:143ad8201 68 49 8b 73 38 mov rsi, [r11+0x38]
.text:143ad8205 68 49 8b 7b 40 mov rdi, [r11+0x40]
.text:143ad8209 68 -8 41 53 push r11
.text:14345885d 70 8 5c pop rsp
.text:14345885e 68 8 41 5f pop r15
.text:143454f99 60 8 41 5e pop r14
.text:143723b27 58 8 41 5d pop r13
.text:143530971 50 8 41 5c pop r12
.text:14384a8a6 48 8 5d pop rbp
.text:141896efd 40 c3 retn
"""
# replace=replaceFunction(search, replace, original, ea, addressList, patternComment)
def patch( search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
# spd = idc.get_spd(ea) # a.k.a `ea`
# printi('search: {}'.format(search))
# sometimes we get passed a context of None
spd = idc.get_spd(ea)
context = kwargs.get('context', None)
if not context:
if obfu_debug: printi("[mark_sp_factory] no context passed at {:x}".format(ea))
return []
else:
slvars = context.get('slvars', None)
if slvars is None:
printi("[mark_sp_factory] no context.slvars passed, using ida's spd")
spd = idc.get_spd(ea)
else:
spd = -slvars.rsp
if spd is None:
printi("[simple_patch_factory] No spd at {:x}".format(ea))
return []
# try:
if idc.get_operand_type(ea, 1) == o_displ:
disp = MakeSigned(idc.get_operand_value(ea, 1), 64)
# if not spd and disp:
# raise RuntimeError("Is this bad?")
else:
disp = 0
if disp:
disp = MyGetOperandDisplacement(ea, 1)
value = spd + disp
if obfu_debug: printi("{:x} storing mark {}: {:x} = {:x} + {:x}".format(ea, mark, value, spd, disp))
patchmarks[mark] = value
cmt = "*[SPD={:x}] '{}' ({:x} = {:x} + {:x})".format(value, mark, value, spd, disp)
Commenter(ea, "line").add(cmt).commit()
# except NameError as e:
# printi("[mark_sp_factory::patch] exception: NameError: {}".format(e.args))
# pass
return []
return patch
def adjust_sp_factory(mark):
"""
Typical Input:
4d 8d 5b ?? lea r11, [r11+8]
"""
global slvars
def patch(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
context = kwargs.get('context', None)
if not context:
if obfu_debug: printi("[adjust_sp_factory] no context passed at {:x}".format(ea))
return []
else:
slvars = context.get('slvars', None)
if mark not in patchmarks:
if obfu_debug: printi("Potential SP adjustment failed due to no patchmark {:x}".format(ea))
return []
value = patchmarks[mark]
disp = 0
if idc.get_operand_type(ea, 1) == o_displ:
disp = MakeSigned(idc.get_operand_value(ea, 1), 8)
if not disp:
printi("{:x} expected idc.get_operand_value to be non-zero".format(ea))
new_value = value + disp
if obfu_debug:
printi("{:x} retrieved mark {}: {:x} + {:x}".format(ea, mark, value, disp))
printi("{:x} changed mark {}: to {:x}".format(ea, mark, new_value))
patchmarks[mark] = new_value
dst = ea
cmt = "[MARK+={:#x}]".format(disp)
Commenter(idc.prev_head(dst), "line").remove_matching(r'^\[MARK')
Commenter(idc.prev_head(dst), "line").add(cmt).commit()
# cmt = "[SPD={}] '{}'".format( hex(_spd), mark )
return patch
def set_sp_factory(mark, offset=0):
"""
Typical Input:
48 8d a5[30 02 00 00] lea rsp, [rbp+0x230] ; will be passed as set_sp_factory input
"""
global slvars
def patch(search=None, replace=None, original=None, ea=None, addressList=None, patternComment=None, addressListWithNops=None, **kwargs):
context = kwargs.get('context', None)
if not context:
if obfu_debug: printi("[set_sp_factory] no context passed at {:x}".format(ea))
return []
slvars = context.get('slvars', None)
if slvars is None:
printi("[mark_sp_factory] no context.slvars passed, using ida's spd")
spd = idc.get_spd(ea)
else:
spd = -slvars.rsp
if mark not in patchmarks:
if obfu_debug: printi("Potential SP adjustment failed due to no patchmark {:x}".format(ea))
return []
value = patchmarks[mark]
disp = 0
if isJmp(ea):
ea += GetInsnLen(ea)
if idc.get_operand_type(ea, 1) == o_displ:
disp = MakeSigned(idc.get_operand_value(ea, 1), 64)
if obfu_debug:
printi("{:x} retrieved mark {}: {:x} + {:x}".format(ea, mark, value, disp))
printi("{:x} adjusting spd from {:x} by {:x} to get {:x}".format(ea, spd, (value + disp) - spd, (value + disp)))
# _spd = (value + disp) - spd
_spd = (value + disp) - spd
if not isinstance(_spd, int):
# dprint("[debug] _spd value, disp, spd")
printi("[debug] _spd:{}, value:{}, disp:{}, spd:{}".format(_spd, value, disp, spd))
if 'trigger' in kwargs:
# idc.add_user_stkpnt(ea + MyGetInstructionLength(ea), _spd + offset)
# printi("should probably add an SPD comment here")
cmt = "[SPD+={:#x}] triggered '{}' ({:x} + {:x} - {:x} ({}))".format(_spd, mark, value, disp, spd, offset if offset is not None else "")
Commenter(ea, "line").remove_matching(r'^\[SPD+=')
Commenter(ea, "line").add(cmt).commit()
# don't add offset to trigger (idk why)
idc.add_user_stkpnt(ea + MyGetInstructionLength(ea), _spd)
# raise "hahaha"
else:
# printi("[debug] _spd:{}, value:{}, disp:{}, spd:{}".format(_spd, value, disp, spd))
dst = idc.get_item_head(ea + len(search))
cmt = "[SPD+={:#x}] '{}' ({:x} + {:x} - {:x} ({}))".format(_spd, mark, value, disp, spd, offset if offset is not None else "")
Commenter(idc.prev_head(dst), "line").remove_matching(r'^\[SPD+=')
Commenter(idc.prev_head(dst), "line").add(cmt).commit()
if obfu_debug: printi("dst started: {:x}".format(dst))
move_to_next = False
if isNop(idc.prev_head(dst)):
while isNop(dst):
move_to_next = True
dst = GetTarget(dst, failnone=True) or idc.next_head(dst)
if obfu_debug: printi("dst finished: {:x}".format(dst))
if move_to_next:
dst = idc.next_head(dst)
printi("dst move to next_head: {:x}".format(dst))
# idc.add_user_stkpnt(ea + len(search), _spd)
idc.add_user_stkpnt(dst, _spd + offset)
# cmt = "[SPD={}] '{}'".format( hex(_spd), mark )
return patch
def mark_sp_reg_factory(reg):
"""
Typical Input:
mov rax, rsp 48 8B C4
sub rsp, 0xb8
lea r11, [rax]
mov rsp, r11
retn
"""
# replace=replaceFunction(search, replace, original, ea, addressList, patternComment)
def patch( search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
# spd = idc.get_spd(ea) # a.k.a `ea`
context = kwargs.get('context', dict())
slvars = context.get('slvars', None)
if not slvars:
printi("[mark_sp_factory] no context.slvars passed, skipping")
return []
spd = -slvars.rsp
disp = idc.get_operand_value(ea, 1)
if not spd and disp:
return
if disp:
disp = MyGetOperandDisplacement(ea, 1)
value = spd + disp
printi("{:x} storing reg {}: {:x}".format(ea, reg, value))
patchmarks[reg] = value
return []
return patch
def gen_mask(pattern, previous=None):
previous = A(previous)
if not isinstance(previous, list):
raise Exception("argument 'previous' was not a list (type: {})".format(type(previous)))
if len(previous) < 2:
sometimes = []
always = []
for v in pattern:
sometimes.append(v)
always.append(v)
return [sometimes, always]
sometimes = previous[0]
always = previous[1]
if pattern is None:
mask = []
for i, unused in enumerate(always):
mask.append( ~(sometimes[i] ^ always[i]) )
return [always, mask]
for i, v in enumerate(pattern):
sometimes[i] |= v
always[i] &= v
return [sometimes, always]
def patch_32bit_add(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
"""
replace: 48 81 c1 08 00 00 00 add rcx, 8
with: 48 83 c1 08 add rcx, 8
"""
if obfu_debug: printi("patch_32bit_add")
length = MyGetInstructionLength(ea)
# e = deCode(get_bytes(ea, length), ea)
if not IsValidEA(ea):
return []
e = _.firstOr(de(ea), None)
if not e or e.rawFlags == 0xffff:
return []
# pp(e.__dict__)
# setglobal('e', e)
# setglobal('ea', ea)
flags = e.rawFlags & FLAG_MASK
if e.mnemonic in ('ADD', 'SUB') \
and e.opcode in (11, 51) \
and flags == (FLAG_DST_WR | FLAG_IMM_SIGNED) \
and e.operands[0].type == 'Register' \
and e.operands[1].type == 'Immediate' \
and (e.operands[1].size == 32 or e.operands[1].value < 0):
flip = e.operands[1].value < 0
if flip:
e.operands[1].value = 0 - e.operands[1].value
if e.mnemonic == 'ADD':
e.mnemonic = 'SUB'
elif e.mnemonic == 'SUB':
e.mnemonic = 'ADD'
else:
raise ValueError('Unexpected mnemonic {}'.format(e.mnemonic))
requiredSize = bitsize_signed_2(e.operands[1].value)
if requiredSize == 16:
requiredSize = 32
if obfu_debug: printi("0x%x: patch_32bit_add: acutalSize: %i, requiredSize: %i" % (ea, e.operands[1].size, requiredSize))
if requiredSize == 8:
addresses = addressList[0:e.size]
return (addresses,
(["{} {}, {}".format(e.mnemonic, e.operands[0].name, e.operands[1].value)]))
else:
if obfu_debug: printi("patch_32bit_add: e was type %s" % type(e))
return []
_push_imm = []
def patch_manual_store(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
global _push_imm
imm = idc.get_wide_byte(addressList[1])
_push_imm.append(imm)
printi("storing push imm: 0x{:x}".format(imm))
def patch_manual(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
global _push_imm
if not _push_imm:
raise ObfuFailure("nothing to pop")
imm = _push_imm.pop()
printi("using push imm: 0x{:x}".format(imm))
if not isInt(ea):
raise ValueError("ea is {}".format(ea))
# sig_maker_ex(obfu.combEx(ea, length=64), fullSig=1, noSig=1, show=1)
return kassemble('add rsp, 0x{:x}'.format(imm))
def patch_double_stack_push_call_jump(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
# 48 ?? ?? ?? ?? ?? ?? mov rax, qword [LoadLibraryA]
# 48 ?? ?? ?? lea rdx, qword [rbp+48h]
# 48 ?? ?? mov rcx, rdx ; mov library name into rcx
# 55 push rbp
# 48 ?? ?? ?? ?? ?? ?? lea rbp, qword [sub_144A4AF5F]
# 48 ?? ?? 24 xchg rbp, [rsp]
# 50 push rax
# c3 retn
# -- a different example
# 48 8b 05 14 91 05 fd mov rax, qword [AddVectoredExceptionHandler]
# 48 8d 15 a6 4f 0e 00 lea rdx, qword [loc_14486BDC5]
# b9 01 00 00 00 mov ecx, 1
# 55 push rbp
# 48 8d 2d ad b0 4b 00 lea rbp, qword [sub_144ACFED4]
# 48 87 2c 24 xchg rbp, [rsp]
# 50 push rax
# c3 retn
# -- a different example
# 48 8b 05 f8 cc 04 fe mov rax, qword [SetUnhandledExceptionFilter]
# 48 8d 15 54 6d 65 01 lea rdx, qword [byte_144DE9A5F]
# 52 push rdx
# 59 pop rcx
# 55 push rbp
# 48 8d 2d 6d da 65 01 lea rbp, qword [sub_144DF078B]
# 48 87 2c 24 xchg rbp, [rsp]
# 50 push rax
# c3 retn
# mov rax, [0x1417f2798]
# lea rdx, [rbp+0x48]
# push rdx
# pop rcx
# lea rsp, [rsp-0x8]
# mov [rsp], rbp
# lea rbp, [0x144345cd3]
# xchg [rsp], rbp
# push rax
# retn
# -- a false positive
# mov rax, cs:LoadLibraryA
# lea rdx, [rbp+48h]
# push rdx
# pop rcx
# mov [rbp+100h], rax
# mov rax, [rbp+100h]
# mov [rbp+150h], rax
# lea rax, [rbp+48h]
# jmp loc_14424AFE2 ; [obfu
# b1180 example
# 48 8b 05 43 dd 00 fd mov rax, [off_140D0AB4C] ; flags are 0x30509574
# 8b 15 2d 6c d6 fc mov edx, [dword_140A63A3C]
# 89 d1 mov ecx, edx
# 55 push rbp
# 48 8d 2d a2 bc db ff lea rbp, [label22]
# 48 87 2c 24 xchg [rsp], rbp
# 50 push rax
# c3 retn
# all our arguments are basically useless, we're going to have to start from scratch.
# first check if we're actually loading something that is actually code
# idc.is_code(idc.get_full_flags(GetOperandValue(EA(), 1)))
target = GetOperandValue(ea, 1)
flags = idc.get_full_flags(target)
# dprint("[debug] target, flags")
if obfu_debug: printi("[patch_double_stack_push_call_jump] target:{:x}, flags:{:x}".format(target, flags))
if idc.is_code(flags) \
or flags == 0x305054a0 \
or flags & idc.FF_0OFF \
or (type(idc.GetDisasm(target)) is str and idc.GetDisasm(target).startswith("extrn")) \
or (type(idc.get_type(target)) is str and idc.get_type(target).endswith(")")):
# raise ObfuFailure("0x%x: serious business: %s {%s}" % (addressList[0], GetDisasm(target), GetDisasm(target)))
state = 0
solution = []
callAddress = BADADDR
jmpAddress = BADADDR
addrLen = len(addressList)
insAddresses = []
i = 0
while i < addrLen:
addr = addressList[i]
insAddresses.append(addr)
skip = MyGetInstructionLength(addr)
if obfu_debug: printi("skipped %i addressList" % skip)
i += skip
if obfu_debug: printi("insAddresses: %s" % insAddresses) # not used yet
ourAddressList = []
inslen = MyGetInstructionLength(ea)
skip = 0
end = 0
for idx, a in enumerate(insAddresses):
# d = re.sub(r'\s+', ' ', GetDisasm(a))
d = dinjasm(a)
if (1 + idx) < len(insAddresses):
dpeek = dinjasm(insAddresses[idx + 1])
else:
dpeek = ""
# printi("0x%x: state: %i: %s" % (a, state, d))
inslen = MyGetInstructionLength(a)
# not used yet
for i in range(inslen):
ourAddressList.append(a + i)
# 0x144a91628: state: 0: mov rax, qword ptr cs:[LoadLibraryA]
# 0x144a9162f: state: 1: lea rdx, qword ptr [rbp+48h]
# 0x144a91633: state: 1: push rdx
# 0x144a91634: state: 1: pop rcx
# 0x144345cd3: state: 1: mov qword ptr [rbp+100h], rax
# 0x144345cda: state: 1: mov rax, qword ptr [rbp+100h]
#
# .text:0000000144A91628 1B8 48 8B 05 69 11 D6 FC mov rax, cs:LoadLibraryA
# .text:0000000144A9162F 1B8 48 8D 55 48 lea rdx, [rbp+48h]
# .text:0000000144A91633 1B8 52 push rdx
# .text:0000000144A91634 1C0 59 pop rcx
# .text:0000000144345CD3 000 48 89 85 00 01 00 00 mov [rbp+100h], rax
# .text:0000000144345CDA 000 48 8B 85 00 01 00 00 mov rax, [rbp+100h]
# .text:0000000144345CE1 000 48 89 85 50 01 00 00 mov [rbp+150h], rax
# .text:0000000144345CE8 000 48 8D 45 48 lea rax, [rbp+48h]
# .text:0000000144345CEC 000 E9 F1 52 F0 FF jmp loc_14424AFE2 ; [obfu::comb] unconditional jump
# .text:0000000144345CEC ; END OF FUNCTION CHUNK FOR sub_14548F1ED#
if d.startswith("mov rax"):
t = GetOpType(a, 1)
# if t in (idc.o_mem, idc.o_displ) and state == 0:
if state == 0:
callAddress = GetOperandValue(a, 1)
state = 1
# continue, else we'll add this line to our solution
continue
else:
if obfu_debug: printi("sequence: %i" % state)
return [] # raise ObfuFailure("serious business: out of sequence: %s" % d)
elif d.startswith("mov [rsp-8], rbp") \
and dpeek.startswith("lea rsp, [rsp-8]"):
if state == 1:
state = 2
else:
if obfu_debug: printi("serious business: out of sequence: %s" % (d + "; " + dpeek))
return []
elif d.startswith("lea rsp, [rsp-8]") \
and dpeek.startswith("mov [rsp], rbp"):
if state == 1:
state = 2
else:
if obfu_debug: printi("serious business: out of out of sequence: %s" % (d + "; " + dpeek))
return []
elif d.startswith("push rbp"):
if state == 1:
state = 2
else:
if obfu_debug: printi("out of sequence: %i" % state)
return [] # raise ObfuFailure("serious business: out of out of sequence: %s" % d)
# elif d.startswith("lea rbp") and GetOpType(a, 1) in (idc.o_mem, idc.o_displ):
elif d.startswith("lea rbp"):
if state == 2:
jmpAddress = GetOperandValue(a, 1)
if obfu_debug: printi("jmpAddress: 0x%x" % jmpAddress)
state = 3
else:
if obfu_debug: printi("0x%x: serious business: out of out of sequence (%s): %s" % (ea, state, d))
return []
elif d.startswith("xchg rbp, [rsp]") \
or d.startswith("xchg [rsp], rbp"):
if state == 3:
state = 4
else:
if obfu_debug: printi("0x%x: serious business: out of out of sequence (%s): %s" % (ea, state, d))
return []
elif d.startswith("push rax"):
if state == 4:
state = 5
else:
if obfu_debug: printi("0x%x: serious business: out of out of sequence (%s): %s" % (ea, state, d))
return []
elif d.startswith("ret"):
if state == 5:
state = 6
end = insAddresses[idx] + GetInsnLen(insAddresses[idx])
break
else:
if obfu_debug: printi("out of sequence: %i" % state)
if state > 2:
if obfu_debug: printi("0x%x: serious business: out of out of sequence (%s): %s" % (ea, state, d))
return []
else:
return []
if state == 1:
# solution.append(dii(a))
solution.append(d)
if state == 6:
# solution.append("CALL 0x%x" % callAddress)
# solution.append("JMP 0x%x" % jmpAddress)
# this way...
usedAddresses = []
for a in addressList:
if a == end:
break
usedAddresses.append(a)
# --or--
# https://stackoverflow.com/questions/5883265/python-add-item-to-list-until-a-condition-is-true
usedAddresses2 = [x for x in it.takewhile(lambda x: x != end, addressList)]
usedCount = len(usedAddresses)
# compact, but readable? ... compact: yes, readable: hardly
printi("usedAddresses1: %s" % usedAddresses)
printi("usedAddresses2: %s" % usedAddresses)
solution.append("call qword [rel 0x%x]" % callAddress)
solution.append("jmp 0x%x" % jmpAddress)
printi("Possible solution:\n%s" % "\n".join(solution))
return (usedAddresses, solution)
# return (usedAddresses,
# return (search, replace, original, ea, addressList, patternComment, addressListWithNops)
elif state > 4:
raise ObfuFailure("{:x} serious business: only reached state {} of 6".format(addressList[0], state))
return []
def patch_double_rsp_push_call_jump(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
"""
0: 55 push rbp
1: 48 8d 2d ?? ?? ?? ?? lea rbp,[rip+0xffffffff]
8: 48 87 2c 24 xchg QWORD PTR [rsp],rbp
c: 55 push rbp
d: 48 8d 2d ?? ?? ?? ?? lea rbp,[rip+0x1e650e]
14: 48 87 2c 24 xchg QWORD PTR [rsp],rbp
18: c3 ret
19:
"""
jmpAddress = GetOperandValue(addressList[0x01], 1)
callAddress = GetOperandValue(addressList[0x0d], 1)
# we can return the entire addressList, as this is a terminal pattern
# (it ends it retn)
return (addressList, [
"call 0x{:x}".format(callAddress),
"jmp 0x{:x}".format(jmpAddress),
"int3"
# "ret"
])
def patch_double_rsp_push_call_jump_b(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
"""
0: 55 push rbp
(shoe-horn in 48 8d 64 24 f8 instead of 55)
1: 48 8d 2d ?? ?? ?? ?? lea rbp,[rip+0xffffffff]
8: 48 87 2c 24 xchg QWORD PTR [rsp],rbp
c: 55 push rbp
d: 48 8d 2d ?? ?? ?? ?? lea rbp,[rip+0x1e650e]
14: 48 87 2c 24 xchg QWORD PTR [rsp],rbp
18: c3 ret
19:
"""
jmpAddress = GetOperandValue(addressList[0x01 + 4], 1)
callAddress = GetOperandValue(addressList[0x0d + 4], 1)
# we can return the entire addressList, as this is a terminal pattern
# (it ends it retn)
return (addressList, [
"call 0x{:x}".format(callAddress),
"jmp 0x{:x}".format(jmpAddress),
"int3"
# "ret"
])
def patch_single_rsp_push_call_jump(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
"""
0: 55 push rbp
1: 48 8D 2D[AB 37 35 00] lea rbp, sub_143C53296
8: 48 87 2C 24 xchg QWORD PTR [rsp],rbp
c: E9[03 DC DC FF] jmp _sub_1436CD6F7
0: e8[0f dc dc ff] call _sub_1436CD6F7
5: e9[a9 37 35 00] jmp sub_143C53296
"""
"""
0: 48 8b 05[?? ?? ?? ??] mov rax,QWORD PTR [rip+0x366a13] # 0x366a1a
7: 8b 15 b8 3e 7f fc mov edx,DWORD PTR [rip+0xfffffffffc7f3eb8] # 0xfffffffffc7f3ec5
d: 89 d1 mov ecx,edx
f: 55 push rbp
10: 48 8d 2d[?? ?? ?? ??] lea rbp,[rip+0x56a224] # 0x56a23b
17: 48 87 2c 24 xchg QWORD PTR [rsp],rbp
1b: ff e0 jmp rax
"""
if (search[0] == 0x55 and isUnconditionalJmp(addressList[1+7]+4)):
_asm = ["call {:#x}".format(GetTarget(addressList[1+7]+4)), "jmp {:#x}".format(addressList[1] + 7 + MakeSigned(idc.get_wide_dword(addressList[1]+3))), "int3"]
try:
nassemble(_asm, quiet=1)
return _asm
except RelocationAssemblerError:
print('nope')
pass
if (search[0] == 0x48):
jmpAddress = idc.get_operand_value(addressList[0x10], 1)
callOffset = idc.get_operand_value(addressList[0], 1)
callAddress = idc.get_qword(callOffset)
addressJmp = 0
printi("{:x} [patch_single_rsp_push_call_jump(push rax)] jmpAddress:{:x}, callOffset:{:x} callAddress:{:x}".format(ea, jmpAddress, callOffset, callAddress))
if callAddress != idc.BADADDR:
ForceFunction(callAddress)
obfu._patch(callAddress)
# nassemble(addressJmp, "jmp 0x{:x}".format(jmpAddress), apply=1)
return len(search), [
"call 0x{:x}".format(callAddress),
"jmp 0x{:x}".format(jmpAddress),
"int3",
]
return []
jmpAddress = GetOperandValue(addressList[0x01], 1)
# we can't see `jmp` instructions because they're purposefully hidden for chunk processing
addressJmp = addressList[0x0b] + 1
# dprint("[patch_single_rsp_push_call_jump] jmpAddress, addressJmp")
if isUnconditionalJmp(addressJmp):
printi("{:x} [patch_single_rsp_push_call_jump] jmpAddress:{:x}, addressJmp:{:x}".format(ea, jmpAddress, addressJmp))
callAddress = GetTarget(addressJmp)
# Now we have to check what's next, to avoid clobbering other patterns
addressNext = callAddress + GetInsnLen(callAddress)
# dprint("[patch_single_rsp_push_call_jump] callAddress, addressNext")
printi("{:x} [patch_single_rsp_push_call_jump] callAddress:{:x}, addressNext:{:x}".format(ea, callAddress, addressNext))
if IdaGetMnem(callAddress) in ('ret', 'retn', 'xchg') or \
IdaGetMnem(addressNext) in ('ret', 'retn', 'xchg'):
printi("{:x} [patch_single_rsp_push_call_jump] fail: retn/xchg in callAddress:{:x}, addressNext:{:x}".format(ea, callAddress, addressNext))
return []
# XXX: removed this, not sure what it was meant for -- some kind of safety net i guess
if 1:
if not IsFuncHead(callAddress) and len(xrefs_to_ex(callAddress, flow=0)) < 1:
printi("{:x} [patch_single_rsp_push_call_jump] fail: not enough xrefs ({}) to callAddress:{:x}".format(ea, len(xrefs_to_ex(callAddress, flow=0)), callAddress))
return []
""" some real subs
.text:00000001441DC002 000 push rbp ; [PatchBytes] lea rsp, qword ptr [rsp-8]; mov [rsp], rbp
.text:00000001441DC003 008 nop dword ptr [rax+rax+00000000h]
.text:00000001441DC00B 008 sub rsp, 40h
.text:00000001441DC00F 048 lea rbp, [rsp+20h]
.text:00000001441DC014 048 mov [rbp+30h], rcx
(same sub, before de-obfu)
.text:00000001441DC002 000 lea rsp, [rsp-8]
.text:00000001441DC007 008 mov [rsp+8+var_8], rbp
.text:00000001441DC00B 008 sub rsp, 40h
.text:00000001441DC00F 048 lea rbp, [rsp+48h+var_28]
.text:00000001441DC014 048 mov [rbp+30h], rcx
"""
if callAddress != idc.BADADDR:
ForceFunction(callAddress)
obfu._patch(callAddress)
# nassemble(addressJmp, "jmp 0x{:x}".format(jmpAddress), apply=1)
return len(search), [
"call 0x{:x}".format(callAddress),
"jmp 0x{:x}".format(jmpAddress),
"int3",
]
else:
printi("{:x} [patch_single_rsp_push_call_jump] fail: callAddress:{:x} BAD".format(ea, callAddress))
pass
# "ret"
return []
def patch_checksummer(search, replace, original, ea, addressList, patternComment, addressListWithNops, **kwargs):
# idc.patch_dword(addressList[4], idc.get_wide_dword(addressList[4]) - 0x20)
# PatchNops(addressList[8], 5)
value = idc.get_wide_dword(addressList[4]) - 0x20
# 55 48 8D AC 24
# 0-value
# 60 FF FF FF
# idc.patch_byte(addressList[12], value)
# PatchNops(addressList[1], 7)
return (addressList[0:13], [
"push rbp",
"sub rsp, 0{:x}h".format(value),
"lea rbp, [rsp]"
])
def process_replace(replace, replace_asm):
ra = kassemble(replace_asm)
# printi("pr", replace, ra, replace_asm.split(';'))
if ra == replace:
return replace_asm.split(';')
printi("[warn] incorrect hex for asm: {}\n[warn] ... should be {}".format(replace_asm, listAsHex(ra)))
return replace_asm.split(';')
def process_replace_nocheck(replace, replace_asm):
return replace_asm.split(';')
def process_hex_pattern(replace):
hp = hex_pattern(replace)
d = _.flatten(_.pluck(diInsns(hp), 3))
def fn(value, index, container):
return [int(x, 16) for x in re.split('(..)', value) if x]
d = _.flatten(_.map(d, fn))
#
if d == hp:
return _.flatten(_.pluck(diInsns(hp), 2))
printi("process_hex_pattern", d, hp, _.flatten(_.pluck(diInsns(hp), 2)))
return hex_pattern(replace)
def obfu_append_patches():
global obfu
obfu.patterns = list()
# obfu.append("", "push r11, pop rsp -> mov rsp, r11", hex_pattern(["41 53", "5c"]), hex_pattern(["4C 89 dc"]), safe=1)
# obfu.append("", "push r11, pop rsp -> mov rsp, r11", hex_pattern(["41 53", "5c"]), ["mov rsp, r11"], safe=1)
"""
028 -250 48 81 ec 50 02 00 00 sub rsp, 0x250
278 48 8d 6c 24 20 lea rbp, [rsp+0x20]
48 8d ac 24 80 00 00 00 lea rbp, [rsp+80h]
.....................................................
48 8d a5 30 02 00 00 lea rsp, [rbp+0x230]
....
"""
obfu.append("", "mark lea rbp, [rsp+x]", hex_pattern("48 8d ac 24 ?? ?? ?? ??"), [], mark_sp_factory('lea_rbp_rsp_x'))
obfu.append("", "mark lea rbp, [rsp+x]", hex_pattern("48 8d 6c 24 ??"), [], mark_sp_factory('lea_rbp_rsp_x'))
obfu.append("", "set lea rsp, [rbp+x]", hex_pattern("48 8d a5 ?? ?? ?? ??"), [], set_sp_factory('lea_rbp_rsp_x'))
obfu.append("", "set lea rsp, [rbp+x]", hex_pattern("48 8d 65 ??"), [], set_sp_factory('lea_rbp_rsp_x'))
obfu.append("", "set mov rsp, rbp", hex_pattern("48 8b e5"), [], set_sp_factory('lea_rbp_rsp_x'))
obfu.append("", "mov r11, rsp", hex_pattern("4c 8b dc") or nassemble("mov r11, rsp"), [], mark_sp_factory('mov_r11_rsp'))
obfu.append("", "lea r11, [rsp+??h]", hex_pattern("4c 8d 5c 24 ??") or nassemble("lea r11, [rsp+60h]"), [], mark_sp_factory('mov_r11_rsp'))
obfu.append("", "lea r11, [rsp+????????h]",
hex_pattern("4c 8d 9c 24 ?? ?? ?? ??") or nassemble("lea r11, [rsp+]"), [], mark_sp_factory('mov_r11_rsp'))
obfu.append("", "mov rsp, r11", hex_pattern("49 8b e3") or nassemble("mov rsp, r11"), [], set_sp_factory('mov_r11_rsp'))
# needs to be rewritten for obfu_patches, gets a bit confused. works much better as a trigger from slowtrace2
"""
41 53 push r11
5c pop rsp
"""
obfu.append("", "push r11; pop rsp", hex_pattern("90 41 53 5c") or nassemble("push r11; pop rsp"), [], set_sp_factory('mov_r11_rsp', 8), trigger='mov_r11_rsp')
obfu.append("", "lea r11, [r11+??h]", hex_pattern("4d 8d 5b ??"), [], adjust_sp_factory('mov_r11_rsp'))
obfu.append("""
0: 48 8d 64 24 f8 lea rsp, [rsp-0x8]
5: 48 89 2c 24 mov [rsp], rbp
9: 48 8d 2d ?? ?? ?? ?? lea rbp, [rip+0x0] # 0x10
10: 48 87 2c 24 xchg [rsp], rbp
14: 48 8d 64 24 08 lea rsp,[rsp+0x8]
19: ff 64 24 f8 jmp [rsp-0x8]
""", "lea rbp<>rsp jmp variant1 (mit nop)",
hex_pattern([
"48 8d 64 24 f8",
"48 89 2c 24",
"90",
"48 8d 2d ?? ?? ?? ??",
"48 87 2c 24",
"48 8d 64 24 08",
"ff 64 24 f8"
]), [],
generate_patch1(0x09 + 3 + 1), # , 0x10 + 1, 0x05)
reflow=1
)
obfu.append("""
000 48 89 6C 24 F8 mov [rsp+var_8], rbp ; [PatchBytes] mov/lea->push order swap: rbp
; [PatchBytes] lea rsp, qword ptr [rsp-8]; mov [rsp], rbp
000 48 8D 64 24 F8 lea rsp, [rsp-8]
008 48 83 EC 40 sub rsp, 40h
048 48 8D 6C 24 20 lea rbp, [rsp+20h]
to
000 55 push rbp ; [PatchBytes] mov/lea->push order swap: rbp
; [PatchBytes] lea rsp, qword ptr [rsp-8]; mov [rsp], rbp
008 48 83 EC 40 sub rsp, 40h
048 48 8D 6C 24 20 lea rbp, [rsp+20h]
048 0F 1F 84 00 00 00 00 00 nop dword ptr [rax+rax+00000000h] ; [PatchBytes] PatchNops
048 90 nop
""", "ArxanHelper prologue",
hex_pattern([
"48 89 6C 24 F8",
"48 8D 64 24 F8",
"48 83 EC 40",
"48 8D 6C 24 20",
]),
hex_pattern([
"55",
"48 83 EC 40",
"48 8D 6C 24 20",
]),
safe=1,
reflow=1
)
# obfu.append("""
# 0: 48 8d 64 24 f8 lea rsp, [rsp-8] ; === call LOCATION_2, insert LOCATION_1 into return stack
# 5: 48 89 2c 24 mov [rsp], rbp ; push rbp
# 9: 48 8d 2d ?? ?? ?? ?? lea rbp, LOCATION_1 ; rbp = LOCATION_1
# 10: 48 87 2c 24 xchg rbp, [rsp] ; pop rbp ; push LOCATION_1 ; push LOCATION_1
# 14: 55 push rbp ; push rbp
# 15: 48 8d 2d ?? ?? ?? ?? lea rbp, LOCATION_2 ; rbp = LOCATION_2
# 1c: 48 87 2c 24 xchg rbp, [rsp] ; pop rbp; push LOCATION_2 ; push LOCATION_2
# 20: c3 retn ; pop rax; jmp eax ; pop rax; jmp rax
# """,
# "faked call to LOCATION_2 from LOCATION_1 ",
# hex_pattern([
# "48 8d 64 24 f8",
# "48 89 2c 24",
# "48 8d 2d ?? ?? ?? ??",
# "48 87 2c 24",
# "55",
# "48 8d 2d ?? ?? ?? ??",
# "48 87 2c 24",
# "c3"
# ]),
# [],
# generate_call_with_fake_return(0x18)
# )
# 0: 58 pop rax # 0: 50 push rax
# 1: 59 pop rcx # 1: 51 push rcx
# 2: 5a pop rdx # 2: 52 push rdx
# 3: 5b pop rbx # 3: 53 push rbx
# 4: 5c pop rsp # 4: 54 push rsp
# 5: 5d pop rbp # 5: 55 push rbp
# 6: 5e pop rsi # 6: 56 push rsi
# 7: 5f pop rdi # 7: 57 push rdi
# 8: 41 58 pop r8 # 8: 41 50 push r8
# a: 41 59 pop r9 # a: 41 51 push r9
# c: 41 5a pop r10 # c: 41 52 push r10
# e: 41 5b pop r11 # e: 41 53 push r11
# 10: 41 5c pop r12 # 10: 41 54 push r12
# 12: 41 5d pop r13 # 12: 41 55 push r13
# 14: 41 5e pop r14 # 14: 41 56 push r14