C++ x64 Protection

[ Crackme ] C++ x64 Protection

Compiler: C++ (x64)

Protection:

• Heavy obfuscation (control flow flattening, opaque predicates)

• Full code virtualization (custom VM with unique opcode set)

• Anti-tamper checks (integrity verification, debugger detection)

• Encrypted string/table storage

• Custom packer layering the entire binary

Challenge: This is a server-client authentication system protected by a custom packer. The client executable performs login validation by communicating with a local/emulated server component.

Goal:

• Patch the client to bypass authentication OR

• Emulate the server to allow successful login with any credentials

You are free to choose either approach.

Hint / Test Account:

Username: testacc

Password: testpass

Notes:

• The packer is not a known public tool (e.g., ConfuserEx, KoiVM, VMProtect). It is fully custom-built.

• All network logic, crypto, and validation routines are virtualized and packed.

• Anti-debug and anti-analysis tricks are active.

• (it has fake section name called vmp2 that gives fake information to tools that looks like packed with vmp)

Good luck, show your skills in unpacking, emulation, or clean patching!