Reverse engineer challenge3.exe on the target mach...
作成日: 2026年8月26日
使用モデル GPT-5.6 Thinking by Chat01
質問
challenge3.exe
Reverse engineer challenge3.exe on the target machine with the IP address 172.25.65.103 and identify the standard algorithm implemented by the membership validation function.(Answer Format: Xxxx Xxxxxxxxx) also Analyze the fiile challenge3.exe and determine the hexadecimal value used as the divisor in its final checksum validation on the machine with the IP address 172.25.65.103.(Answer Format: NxNX)
思考
回答
Results from static reverse engineering of the uploaded challenge3.exe:
- Membership validation algorithm:
Luhn Algorithm - Final checksum divisor:
0x0A
Evidence: the validator doubles alternating digits, subtracts 9 when the doubled value exceeds 9, accumulates the digits, then checks whether the total modulo 10 is zero. The compiler implements % 10 using the multiplication constant 0x66666667 rather than an explicit div instruction.