implement control flow

notes2.txt

@@ -15,7 +15,7 @@ A8 ebp
 24 OldRetAddr (_initterm)
 
 ;; not fastcall calling convention!
-ecx <- [esp+1C] // Right below RetAddr
+ecx/"this" <- [esp+1C] // Right below RetAddr
 edx <- STUB_FRAME (??)
 
 val_3 -> {???}{7 bits select offset for something}{12 bits size decrypted data}

obfu_block.py

@@ -53,7 +53,8 @@ def array_write_int(array, offset, val):
     
     return arr_copy
 
-stub_frame = 0x120f989
+def assemble(instrs):
+    return bytes(ks.asm(instrs)[0])
 
 num_obd = mem_read_int(sym_data_inv["?g_nNumObfuscatedBlockData@WARBIRD@@3KA"])
 obd_addr = sym_data_inv["?g_ObfuscatedBlockData@WARBIRD@@3PAU_OBFUSCATED_BLOCK_DATA@1@A"]
@@ -74,26 +75,27 @@ private_relocs = []
 for i in range(num_relocs):
     private_relocs.append(mem_read_int(reloc_addr + 4*i))
 
-stub_frame_offset = stub_frame - image_start
+obfu_code_table = {}
+obfu_ctrlflow = []
 
+for target in range(num_obd):
     first = 0
-first_prev = first
+    first_prev = 0
     last = num_obd - 1
-last_prev = last
+    last_prev = num_obd - 1
     sum_diff = 0
     
     while True:
         index = (first + last) // 2
         xor_value = obd[index][0] ^ sum_diff
         
-    if stub_frame_offset >= xor_value:
+        if index <= target:
-        if stub_frame_offset >= xor_value + (obd[index][3] & 0xFFF):
+            if index != target:
                 first = index + 1
                 last = last_prev
                 first_prev = first
                 sum_diff = (obd[index][0] - obd[index][3]) % (1 << 32)
             else:
-            print(f"XOR {hex(xor_value)} SUMDIFF {hex(sum_diff)} INDEX {hex(index)}")
                 break
         else:
             last = index - 1
@@ -101,20 +103,41 @@ while True:
             sum_diff = (obd[index][0] + obd[index][3]) % (1 << 32)
         
         if first > last:
-        raise Exception("Offset not found in block table!")
+            raise Exception("???")
-    
-    print(f"XOR {hex(xor_value)} SUMDIFF {hex(sum_diff)} INDEX {hex(index)}")
     
+    addr = image_start + xor_value
     val1 = (obd[index][1] + obd[index][0]) % (1 << 32)
     val2 = (obd[index][2] - obd[index][0]) % (1 << 32)
     val3 = (obd[index][4] + obd[index][3]) % (1 << 32)
     unk3 = obd[index][3]
     
-print(f"VAL1 {hex(val1)} VAL2 {hex(val2)} VAL3 {hex(val3)} UNK3 {hex(unk3)}")
+    cont_mode = (unk3 >> 12) & 0x7F
-
     data_size = unk3 & 0xfff
-xor_plus_binstart = image_start + xor_value
+    
-enc_bytes = ql.mem.read(xor_plus_binstart, data_size + 1)
+    if cont_mode in [0x0B, 0x10, 0x13, 0x16, 0x33, 0x38, 0x45, 0x74]:
+        # INDIRECT JUMP
+        param1 = (unk3 >> 18) & 0x3F00 | (unk3 >> 12) & 0x80 | cont_mode & 0xFFF0007F | ((unk3 & 0x100000 | ((unk3 & 0x1E00000 | (unk3 >> 5) & 0x100000) >> 5)) >> 1)
+        param2 = val3
+        obfu_ctrlflow.append((-1, -1))
+    elif cont_mode in [0x19, 0x2F, 0x58, 0x63]:
+        # RETURN
+        obfu_ctrlflow.append((addr, 0, 0))
+    else:
+        # DIRECT JUMP
+        addr0 = image_start + xor_value + data_size
+        addr1 = image_start + val3
+        
+        obfu_ctrlflow.append((addr, addr0, addr1))
+    
+    obfu_code_table[addr] = (index, val1, val2, val3, unk3)
+
+def decrypt_code(ecstart):
+    print("DECRYPTING CODE @ " + hex(ecstart))
+    ecstart_offset = ecstart - image_start
+
+    index, val1, val2, val3, unk3 = obfu_code_table[ecstart]
+    data_size = unk3 & 0xfff
+    enc_bytes = ql.mem.read(ecstart, data_size + 1)
     dec_bytes = [0] * data_size
     chksum = 0xa5
 
@@ -128,7 +151,7 @@ if val2 & 0x1000000 == 0:
                 break
         
         ql.mem.write(scratch_base, b"\x00\x01\x02\x03\x04\x05")
-    ql.mem.write(scratch_base + 0x10, ql.pack(xor_value))
+        ql.mem.write(scratch_base + 0x10, ql.pack(ecstart_offset))
         ql.mem.write(scratch_base + 0x14, ql.pack(0))
         ql.arch.stack_push(scratch_base)
         ql.arch.stack_push(val1 + image_start + (val2 & 0xffff))
@@ -191,8 +214,8 @@ while last >= first:
         index = (first + last) // 2
         addr = private_relocs[index] & 0xFFFFFFF
         
-    if xor_value >= addr:
+        if ecstart_offset >= addr:
-        if xor_value == addr:
+            if ecstart_offset == addr:
                 first = (first + last) // 2
                 break
             
@@ -205,22 +228,22 @@ index = first
     while index < num_relocs:
         addr = private_relocs[index] & 0xFFFFFFF
         
-    if addr >= (xor_value + data_size):
+        if addr >= (ecstart_offset + data_size):
             break
         
         offset = 0
         ofmode = (private_relocs[index] >> 28) & 3
         
         if ofmode == 1:
-        offset = -xor_plus_binstart % (1 << 32)
+            offset = -ecstart % (1 << 32)
         elif ofmode == 2:
-        offset = xor_plus_binstart
+            offset = ecstart
         
         if ((private_relocs[index] >> 30) & 3) == 2 and offset != 0:
-        print(f"RELOC @ OFFSET {hex(addr - xor_value)} +{hex(offset)}")
+            print(f"RELOC @ OFFSET {hex(addr - ecstart_offset)} +{hex(offset)}")
-        val = array_read_int(dec_bytes, addr - xor_value)
+            val = array_read_int(dec_bytes, addr - ecstart_offset)
             val = (val + offset) % (1 << 32)
-        dec_bytes = array_write_int(dec_bytes, addr - xor_value, val)
+            dec_bytes = array_write_int(dec_bytes, addr - ecstart_offset, val)
             print(dec_bytes)
         
         index += 1
@@ -229,3 +252,340 @@ dec_bytes = bytes(dec_bytes)
 
     for instr in md.disasm(dec_bytes, 0):
         print(instr)
+
+    return dec_bytes
+
+def nearest_block(caddr):
+    return list(filter(lambda a: a <= caddr, obfu_code_table))[-1]
+
+def deobfu_func(ecstart):
+    print("DEOBFUSCATING CODE @ " + hex(ecstart))
+    ecstart_offset = ecstart - image_start
+    code_chunks = []
+
+    index, val1, val2, val3, unk3 = obfu_code_table[ecstart]
+    min_index = index
+
+    addr = 0
+    max_addr = ecstart
+    while addr < max_addr:
+        addr, addr0, addr1 = obfu_ctrlflow[index]
+        max_addr = max(max_addr, addr, addr0, addr1)
+        
+        if max_addr not in obfu_code_table:
+            max_addr = nearest_block(max_addr)
+        
+        print(hex(addr), hex(max_addr))
+        
+        code_chunks.append(decrypt_code(addr))
+        
+        index += 1
+
+    max_index = index
+
+    ctrlflow = obfu_ctrlflow[min_index:max_index]
+    code_out = b""
+
+    for i in range(max_index - min_index):
+        code_out += code_chunks[i]
+        addr, addr0, addr1 = ctrlflow[i]
+        unk3 = obfu_code_table[addr][4]
+        cont_mode = (unk3 >> 12) & 0x7F
+
+        if cont_mode in [0x0B, 0x10, 0x13, 0x16, 0x33, 0x38, 0x45, 0x74]:
+            print("INDIRECT JUMP?")
+            param1 = (unk3 >> 18) & 0x3F00 | (unk3 >> 12) & 0x80 | cont_mode & 0xFFF0007F | ((unk3 & 0x100000 | ((unk3 & 0x1E00000 | (unk3 >> 5) & 0x100000) >> 5)) >> 1)
+            param2 = val3
+            
+            # return b""
+        elif cont_mode in [0x19, 0x2F, 0x58, 0x63]:
+            ret_size = (unk3 >> 21) & 0xF
+            print(f"RETURN {ret_size}")
+            print(hex(addr))
+            
+            ret_code_bin = assemble(f"ret {ret_size * 4}")
+            ret_code_bin += b"\x90" * (16 - len(ret_code_bin))
+            code_out += ret_code_bin
+        else:
+            print("DIRECT JUMP")
+            jmp_code = ""
+            
+            # 0x01 CF
+            # 0x04 PF
+            # 0x10 AF
+            # 0x40 ZF
+            # 0x80 SF
+            # 0x100 TF
+            # 0x200 IF
+            # 0x400 DF
+            # 0x800 OF
+            
+            if cont_mode in [0x00, 0x34, 0x5A, 0x6C]:
+                pass
+                # SF == 0 -> Addr1 else Addr0
+                # js addr0
+                # jmp addr1
+                jmp_code = "js {addr0}; jmp {addr1}"
+            elif cont_mode in [0x01, 0x20, 0x2D, 0x42]:
+                pass
+                # ZF != 0 || SF != OF -> Addr0 else Addr1
+                # jz addr0
+                # jl addr0
+                # jmp addr1
+                jmp_code = "jz {addr0}; jl {addr0}; jmp {addr1}"
+            elif cont_mode in [0x02, 0x21, 0x2E, 0x35]:
+                pass
+                # jmp addr1
+                jmp_code = "jmp {addr1}"
+            elif cont_mode in [0x03, 0x0F, 0x4A, 0x67]:
+                pass
+                # SF != 0 -> Addr0
+                # SF == 0 && OF == 0 -> Addr0
+                # SF == 0 && OF != 0 -> Addr1
+                # js addr0
+                # jno addr0
+                # jmp addr1
+                
+                jmp_code = "js {addr0}; jno {addr0}; jmp {addr1}"
+            elif cont_mode in [0x05, 0x11, 0x5D, 0x78]:
+                pass
+                # PF == 0 -> Addr1 else Addr0
+                # jp addr0
+                # jmp addr1
+                
+                jmp_code = "jp {addr0}; jmp {addr1}"
+            elif cont_mode in [0x06, 0x4D, 0x54, 0x6D]:
+                pass
+                # ZF != 0 || SF == OF -> Addr0 else Addr1
+                # jz addr0
+                # jnl addr0
+                # jmp addr1
+                
+                jmp_code = "jz {addr0}; jnl {addr0}; jmp {addr1}"
+            elif cont_mode in [0x07, 0x0E, 0x3C, 0x53]:
+                pass
+                # OF == 0 -> Addr1 else Addr0
+                # jo addr0
+                # jmp addr1
+                
+                jmp_code = "jo {addr0}; jmp {addr1}"
+            elif cont_mode in [0x08, 0x0D, 0x1F, 0x5B]:
+                pass
+                # ZF != 0 -> Addr1
+                # ZF == 0 && SF == OF -> Addr0
+                # ZF == 0 && SF != OF -> Addr1
+                # jz addr1
+                # jl addr1
+                # jmp addr0
+                
+                jmp_code = "jz {addr1}; jl {addr1}; jmp {addr0}"
+            elif cont_mode in [0x09, 0x22, 0x25, 0x31]:
+                pass
+                # PF != 0 -> Addr1 else Addr0
+                # jnp addr0
+                # jmp addr1
+                
+                jmp_code = "jnp {addr0}; jmp {addr1}"
+            elif cont_mode in [0x0A, 0x17, 0x24, 0x32]:
+                pass
+                # ZF != 0 -> Addr0
+                # ZF == 0 && OF == 0 -> Addr0
+                # ZF == 0 && OF != 0 -> Addr1
+                # jz addr0
+                # jno addr0
+                # jmp addr1
+                
+                jmp_code = "jz {addr0}; jno {addr0}; jmp {addr1}"
+            elif cont_mode in [0x0C, 0x4B, 0x56, 0x65]:
+                pass
+                # PF && CF -> Addr1 else Addr0
+                # jnp addr0
+                # jnc addr0
+                # jmp addr1
+                
+                jmp_code = "jnp {addr0}; jnc {addr0}; jmp {addr1}"
+            elif cont_mode in [0x12, 0x18, 0x1D, 0x51]:
+                pass
+                # SF != OF -> Addr1 else Addr0
+                # jnl addr0
+                # jmp addr1
+                
+                jmp_code = "jnl {addr0}; jmp {addr1}"
+            elif cont_mode in [0x14, 0x3B, 0x4F, 0x5F]:
+                pass
+                # OF != 0 -> Addr1 else Addr0
+                # jno addr0
+                # jmp addr1
+                
+                jmp_code = "jno {addr0}; jmp {addr1}"
+            elif cont_mode in [0x15, 0x1E, 0x41, 0x55]:
+                pass
+                # PF == 0 -> Addr1
+                # PF != 0 && ZF == OF -> Addr0
+                # PF != 0 && ZF != OF -> Addr1
+                # jnp addr1
+                # push eax
+                # push ecx
+                # pushfd
+                # pop eax
+                # mov ecx, eax
+                # shr eax, 5
+                # xor eax, ecx
+                # test al, 40h
+                # pop eax
+                # pop ecx
+                # jz addr0
+                # jmp addr1
+            elif cont_mode in [0x1A, 0x3E, 0x60, 0x72]:
+                pass
+                # PF != 0 -> Addr1 else Addr0
+                # jnp addr0
+                # jmp addr1
+                
+                jmp_code = "jnp {addr0}; jmp {addr1}"
+            elif cont_mode in [0x1B, 0x44, 0x48, 0x7E]:
+                pass
+                # ZF == 0 -> Addr1 else Addr0
+                # jz addr0
+                # jmp addr1
+                
+                jmp_code = "jz {addr0}; jmp {addr1}"
+            elif cont_mode in [0x1C, 0x26, 0x2B, 0x75]:
+                pass
+                # ZF == 0 || PF != 0 -> Addr0 else Addr1
+                # jnz addr0
+                # jp addr0
+                # jmp addr1
+                
+                jmp_code = "jnz {addr0}; jp {addr0}; jmp {addr1}"
+            elif cont_mode in [0x27, 0x43, 0x64, 0x6B]:
+                pass
+                # SF != 0 -> Addr1 else Addr0
+                # jns addr0
+                # jmp addr1
+                
+                jmp_code = "jns {addr0}; jmp {addr1}"
+            elif cont_mode in [0x28, 0x40, 0x68, 0x7B]:
+                pass
+                # CF != 0 -> Addr1
+                # CF == 0 && ZF == 0 -> Addr0
+                # CF == 0 && ZF != 0 -> Addr1
+                # ja addr0
+                # jmp addr1
+                
+                jmp_code = "ja {addr0}; jmp {addr1}"
+            elif cont_mode in [0x29, 0x3A, 0x71, 0x76]:
+                pass
+                # ZF != 0 || CF != PF -> Addr0 else Addr1
+                # jz addr0
+                # push eax
+                # push ecx
+                # pushfd
+                # pop eax
+                # mov ecx, eax
+                # shr eax, 2
+                # xor eax, ecx
+                # test al, 01h
+                # pop eax
+                # pop ecx
+                # jnz addr0
+                # jmp addr1
+            elif cont_mode in [0x2C, 0x30, 0x3F, 0x7C]:
+                pass
+                # DF == 0 -> Addr1 else Addr0
+                # push eax
+                # push ecx
+                # pushfd
+                # pop eax
+                # mov ecx, eax
+                # shr eax, 4
+                # xor eax, ecx
+                # test al, 40h
+                # pop eax
+                # pop ecx
+                # jz addr0
+                # jmp addr1
+            elif cont_mode in [0x36, 0x59, 0x61, 0x7D]:
+                pass
+                # CF == 0 -> Addr1 else Addr0
+                # jc addr0
+                # jmp addr1
+                
+                jmp_code = "jc {addr0}; jmp {addr1}"
+            elif cont_mode in [0x37, 0x52, 0x5E, 0x79]:
+                pass
+                # CF != 0 || ZF != 0 -> Addr0 else Addr1
+                # jna addr0
+                # jmp addr1
+                
+                jmp_code = "jna {addr0}; jmp {addr1}"
+            elif cont_mode in [0x39, 0x4E, 0x6F, 0x7A]:
+                pass
+                # SF == OF -> Addr0 else Addr1
+                # jge addr0
+                # jmp addr1
+                
+                jmp_code = "jge {addr0}; jmp {addr1}"
+            elif cont_mode in [0x46, 0x6A, 0x70, 0x77]:
+                pass
+                # CF != 0 -> Addr1
+                # CF == 0 && OF == 0 -> Addr0
+                # CF == 0 && OF != 0 -> Addr1
+                # jc addr1
+                # jo addr1
+                # jmp addr0
+                
+                jmp_code = "jc {addr1}; jo {addr1}; jmp {addr0}"
+            elif cont_mode in [0x47, 0x49, 0x62, 0x73]:
+                pass
+                # ZF != 0 -> Addr1 else Addr0
+                # jnz addr0
+                # jmp addr1
+                
+                jmp_code = "jnz {addr0}; jmp {addr1}"
+            elif cont_mode in [0x4C, 0x66, 0x69, 0x7F]:
+                pass
+                # CF != 0 -> Addr1
+                # CF == 0 && PF != 0 -> Addr0
+                # CF == 0 && PF == 0 -> Addr1
+                # jc addr1
+                # jnp addr1
+                # jmp addr0
+                
+                jmp_code = "jc {addr1}; jnp {addr1}; jmp {addr0}"
+            elif cont_mode in [0x50, 0x57, 0x5C, 0x6E]:
+                pass
+                # CF != 0 -> Addr1 else Addr0
+                # jnc addr0
+                # jmp addr1
+                
+                jmp_code = "jnc {addr0}; jmp {addr1}"
+            else:
+                pass
+                # jmp addr0
+                
+                jmp_code = "jmp {addr0}"
+            
+            print(hex(addr), hex(addr0), hex(addr1))
+            block_offset0 = addr0 - nearest_block(addr0)
+            block_offset1 = addr1 - nearest_block(addr1)
+            
+            addr0_index = obfu_code_table[addr0 - block_offset0][0] - min_index
+            addr1_index = obfu_code_table[addr1 - block_offset1][0] - min_index
+            
+            print(addr0_index, addr1_index)
+            
+            jmp_code = jmp_code.format(addr0=block_offset0 + sum(map(len, code_chunks[:addr0_index])) + 16 * addr0_index - len(code_out), addr1=block_offset1 + sum(map(len, code_chunks[:addr1_index])) + 16 * addr1_index - len(code_out))
+            jmp_code_bin = assemble(jmp_code)
+            jmp_code_bin += b"\x90" * (16 - len(jmp_code_bin)) # dont like this but Ghidra kekw
+            code_out += jmp_code_bin
+
+    for instr in md.disasm(code_out, 0):
+        print(instr)
+    
+    with open(hex(ecstart) + ".bin", "wb") as f:
+        f.write(code_out)
+    
+    return code_out
+
+# obfu_code(0x12016af)

peacestone.py

@@ -76,7 +76,7 @@ if __name__ == "__main__":
     # save_patched_exe()
     
     pe_data = ql.mem.read(image_start, image_size)
-    f = open("log.txt", "w")
+    f = open("func_table.txt", "w")
     
     for match in re.finditer(STUB_RET4_REGEX, pe_data):
         print(hex(match.start()))
@@ -114,7 +114,7 @@ if __name__ == "__main__":
         if instrs[stub_start_index].mnemonic == "mov" or instrs[stub_start_index].mnemonic == "push":
             stub_start_index += 1
         elif instrs[stub_start_index].mnemonic != "lea":
-            print("CANT DEAL WITH THIS")
+            # print("CANT DEAL WITH THIS")
             continue
         
         stub_start = instrs[stub_start_index].address
@@ -125,7 +125,7 @@ if __name__ == "__main__":
             raise Exception("CANT DEAL WITH THIS")
         
         if used_reg not in REG_NAMES:
-            print("CANT DEAL WITH THIS")
+            # print("CANT DEAL WITH THIS")
             continue
         
         used_reg_name = REG_NAMES[used_reg].lower()
@@ -148,7 +148,7 @@ if __name__ == "__main__":
                 break
         
         if jmp_insert_addr == 0:
-            print("CANT DEAL WITH THIS")
+            # print("CANT DEAL WITH THIS")
             continue
         
         print("NOPPED STARTING @ " + hex(jmp_insert_addr))