F1vm 32 Bit -
Run the binary:
while True: op = mem[pc] pc += 1 if op == 0x01: # MOV reg, imm r = mem[pc]; pc += 1 imm = struct.unpack('<I', mem[pc:pc+4])[0]; pc += 4 reg[r] = imm elif op == 0x02: # ADD src = mem[pc]; dst = mem[pc+1]; pc += 2 reg[dst] += reg[src] elif op == 0x03: # XOR src = mem[pc]; dst = mem[pc+1]; pc += 2 reg[dst] ^= reg[src] elif op == 0x10: # PUSH r = mem[pc]; pc += 1 stack.append(reg[r]) elif op == 0xFF: break # ... other ops f1vm 32 bit
enc = bytes.fromhex("25 73 12 45 9A 34 22 11 ...") key = 0xDEADBEEF flag = '' for i, b in enumerate(enc): shift = (i * 8) % 32 key_byte = (key >> shift) & 0xFF flag += chr(b ^ key_byte) print(flag) Output: Run the binary: while True: op = mem[pc]
f1vm_32bit (ELF 32-bit executable) 2. Initial Analysis file f1vm_32bit Output: imm r = mem[pc]