本帖最后由 ZhangYixiSuccee 于 2026-3-5 00:27 编辑
程序分析
直接运行程序,这个是一个Python版本的二进制程序。- 直接拖到二进制程序识别,可以看到是一个Pyinstall打包的二进制程序,
- 这里X64 DBG or IDA就不好分析了,笔者尝试了这两者,均分析不到有用的东西。
- Python是解释器语言,会通过子进程的方式启动程序,分析相对复杂
Python 程序逆向- 这里需要用工具将二进制程序转成pyc程序,pyc就是Python的编译后的二进制格式文件相对源文件解释要快,
- 然后再反编译车工python程序,就可以进行分析。
这里通过crackme 已经可以看到关键字符串,
然后通过https://pylingual.io/可以对pyc文件进行反编译,可以得到Python文件,
[Python] 纯文本查看 复制代码 # Decompiled with PyLingual (https://pylingual.io)
# Internal filename: 'crackme_easy.py'
# Bytecode version: 3.14rc3 (3627)
# Source timestamp: 1970-01-01 00:00:00 UTC (0)
​
import hashlib
import base64
import sys
def xor_decrypt(data, key):
"""XOR解密"""
result = bytearray()
for i, byte in enumerate(data):
result.append(byte ^ key ^ i & 255)
return result.decode('utf-8', errors='ignore')
def get_encrypted_flag():
"""获取加密的flag"""
enc_data = 'e3w+fiRvfW18fnx4ZAZ6Pj43YwB9OWMXfXo8Dg4O'
return base64.b64decode(enc_data)
def generate_flag():
"""动态生成flag"""
encrypted = get_encrypted_flag()
key = 78
result = bytearray()
for i, byte in enumerate(encrypted):
result.append(byte ^ key)
return result.decode('utf-8')
def calculate_checksum(s):
"""计算校验和"""
total = 0
for i, c in enumerate(s):
total += ord(c) * (i + 1)
return total
def hash_string(s):
"""计算字符串哈希"""
return hashlib.sha256(s.encode()).hexdigest()
def verify_flag(user_input):
"""验证flag"""
correct_flag = generate_flag()
if len(user_input)!= len(correct_flag):
return False
else:
for i in range(len(correct_flag)):
if user_input[i]!= correct_flag[i]:
return False
return True
def fake_check_1(user_input):
"""假检查1"""
fake_hash = 'a1b2c3d4e5f67890abcdef1234567890abcdef1234567890abcdef1234567890'
return hash_string(user_input) == fake_hash
def fake_check_2(user_input):
"""假检查2"""
fake_hash = '1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef'
return hash_string(user_input) == fake_hash
def main():
"""主函数"""
print('==================================================')
print(' CrackMe Challenge - Python Edition')
print('==================================================')
print('Keywords: 52pojie, 2026, Happy New Year')
print('Hint: Decompile me if you can!')
print('--------------------------------------------------')
user_input = input('\n[?] Enter the password: ').strip()
if fake_check_1(user_input):
print('\n[!] Nice try, but not quite right...')
input('\nPress Enter to exit...')
return None
else:
if fake_check_2(user_input):
print('\n[!] You\'re getting closer...')
input('\nPress Enter to exit...')
else:
if verify_flag(user_input):
checksum = calculate_checksum(user_input)
expected_checksum = calculate_checksum(generate_flag())
if checksum == expected_checksum:
print('\n==================================================')
print(' *** SUCCESS! ***')
print('==================================================')
print('[+] Congratulations! You cracked it!')
print(f'[+] Correct flag: {user_input}')
else:
print('\n[!] Checksum failed!')
else:
print('\n[X] Access Denied!')
print('[X] Wrong password. Keep trying!')
input('\nPress Enter to exit...')
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
print('\n\n[!] Interrupted by user')
sys.exit(0)
这里其实就很简单了,将这段程序在python环境里面运行,即可得到flag。 |