The linker is able to get the address of the branching code by taking the rip relative virtual address of the branching operation, which is a signed number, and adding it to the current byte offset into the current routine, plus the size of the branching instruction. For example `LoopDemo@17` + size of the branching instruction, which is six bytes, then adding the signed relative virtual address (0x2A). The result of this simple calculation gives us `LoopDemo@65`, which is correct, the branch goes to `add rsp, 28h` in the above example.
The linker is able to get the address of the branching code by taking the rip relative virtual address of the branching operation, which is a signed number, and adding it to the current byte offset into the current routine, plus the size of the branching instruction. For example `LoopDemo@17` + size of the branching instruction, which is six bytes, then adding the signed relative virtual address (0x2A). The result of this simple calculation gives us `LoopDemo@65`, which is correct, the branch goes to `add rsp, 28h` in the above example.
# Usage - Using Theodosius
Theodosius uses the same class structure as HMDM does. Its a highly modular format which allows for extreme usage, supporting almost every idea one might have. In order to use Theo, you must first define three lambdas, `theo::memcpy_t` a method of copying memory, `theo::malloc_t` a method to allocate executable memory, and lastely `theo::resolve_symbol_t` a lamdba to resolve external symbols.
### theo::memcpy_t - copy memory lambda
This is used to write memory, it is never used to read memory. An example of this lambda using VDM could be:
This uses VDM to syscall into memcpy exported by ntoskrnl... If you want to do something in usermode you can proxy memcpy to `WriteProcessMemory` or any other method of writing memory.
if (!WriteProcessMemory(phandle, dest, src, size, &bytes_handled))
{
std::printf("[!] failed to write process memory...\n");
exit(-1);
}
return dest;
};
```
### theo::malloc_t - allocate executable memory
# Obfuscation
# Obfuscation
The usage of the word obfuscation in this project is use to define any changes made to code, this includes code flow. `obfuscation::obfuscate`, a base class, which is inherited and expanded upon by `obfuscation::mutation`, obfuscates code flow by inserting `JMP [RIP+0x0]` instructions after every single instruction. This allows for a routine to be broken up into unique allocations of memory and thus provides more canvas room for creative ideas.
The usage of the word obfuscation in this project is use to define any changes made to code, this includes code flow. `obfuscation::obfuscate`, a base class, which is inherited and expanded upon by `obfuscation::mutation`, obfuscates code flow by inserting `JMP [RIP+0x0]` instructions after every single instruction. This allows for a routine to be broken up into unique allocations of memory and thus provides more canvas room for creative ideas.