from qiling import * from qiling.const import * from capstone import * from keystone import * import pefile import json import re import numpy as np # Set to binary name BIN_NAME = "sppsvc.exe" # Set to function to be analyzed # ANLZ_FUNC = "?VerifyPKeyByInstalledPidConfig@CSLSLicenseManager@@IBEJPAVCSLPKey@@PBGPAUtagPKEY_BASIC_INFO@@PAPAGPAUDECODED_PKEY_DATA@@@Z" ANLZ_FUNC = "_wmain" # These magic regexes are derived from the byte markers in notes.txt PUSH_REGEX = rb"(?:\x8dd\$\xfc\x89[\x04\x0c\x14\x1c,4<]\$|[PQRSUVW]){2}\x8d[x\x05\r\x15\x1d-5=].{4}" STUB_RET4_REGEX = rb"\x8b[DLT\\lt\|]\$\x04\xc2\x04\x00" STUB_RET0_REGEX = rb"\x87[\x04\x0c\x14\x1c,4<]\$\xc3" STUB_MAX_SIZE = 0x40 # Maximum size of jump stub REG_NAMES = { 19: "EAX", 20: "EBP", 21: "EBX", 22: "ECX", 23: "EDI", 24: "EDX", 29: "ESI" } NOP = b"\x90" with open("syms.json", "r") as f: sym_data = json.loads(f.read()) sym_data = {int(a, 16): b for a, b in sym_data.items()} sym_data_inv = {b: a for a, b in sym_data.items()} sym_addrs = sorted(sym_data) ks = Ks(KS_ARCH_X86, KS_MODE_32) md = Cs(CS_ARCH_X86, CS_MODE_32) md.detail = True md.skipdata = True ql = Qiling(["./rootfs/sppsvc.exe"], "./rootfs") image_start = ql.loader.images[0].base image_end = ql.loader.images[0].end image_size = image_end - image_start pe = pefile.PE(data=ql.mem.read(image_start, image_size)) num_obd = ql.unpack(ql.mem.read(sym_data_inv["?g_nNumObfuscatedBlockData@WARBIRD@@3KA"], 4)) obd_addr = sym_data_inv["?g_ObfuscatedBlockData@WARBIRD@@3PAU_OBFUSCATED_BLOCK_DATA@1@A"] obd = [] for i in range(num_obd): obf_block = [] for j in range(5): obf_block.append(ql.unpack(ql.mem.read(obd_addr + 4*(5*i + j), 4))) obd.append(obf_block) stub_frame = 0x120f989 stub_frame_offset = stub_frame - image_start first = 0 first_prev = first last = num_obd - 1 last_prev = last sum_diff = 0 while True: index = (first + last) // 2 xor_value = obd[index][0] ^ sum_diff if stub_frame_offset >= xor_value: if stub_frame_offset >= xor_value + (obd[index][3] & 0xFFF): 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 last_prev = last sum_diff = (obd[index][0] + obd[index][3]) % (1 << 32) print(f"XOR {hex(xor_value)} SUMDIFF {hex(sum_diff)} INDEX {hex(index)}") 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] data_size = unk3 & 0xfff xor_plus_binstart = image_start + xor_value val1_bytes = val1.to_bytes(4, "little") val2_bytes = val2.to_bytes(4, "little") enc_bytes = ql.mem.read(xor_plus_binstart, data_size + 1) dec_bytes = [0] * data_size chksum = 0xa5 for i in range(data_size - 1, 0, -1): enc_byte = enc_bytes[i] b = enc_bytes[i - 1] if i % 2 == 1: if (enc_byte ^ val1_bytes[3]) % 2 == 1: a = (enc_byte ^ val1_bytes[3] ^ val1_bytes[2] ^ 0x100) >> 1 else: a = (enc_byte ^ val1_bytes[3]) >> 1 if (a ^ b) % 2 == 1: dec_byte = (a ^ b ^ val2_bytes[1] ^ 0x100) >> 1 else: dec_byte = (a ^ b) >> 1 else: if (enc_byte ^ val1_bytes[1]) % 2 == 1: a = (enc_byte ^ val1_bytes[1] ^ val1_bytes[0] ^ 0x100) >> 1 else: a = (enc_byte ^ val1_bytes[1]) >> 1 if (a ^ b) % 2 == 1: dec_byte = (a ^ b ^ val2_bytes[0] ^ 0x100) >> 1 else: dec_byte = (a ^ b) >> 1 chksum ^= dec_byte print(hex(dec_byte)) dec_bytes[i] = dec_byte