const char* works - std::string broken

I try to perform some Signature Scanning. It does actually work pretty good:

findsig((PBYTE)"\x48\x8B\x05\xCC\xCC\xCC\xCC\x48\x87\x78",xxx???xx); Console: Signature found!

but now when i try to recieve it as a std::string via tcp, it will not work. It has the same size as the const char*

std::string bytes; 
findsig((PBYTE)bytes.c_str(),"xxx???xx");

Console: Signature failed!

bytes is containing "\x48\x8B\x05\xCC\xCC\xCC\xCC\x48\x87\x78"

When in print them out with printf, they are 1:1 the same. I just dont get the issue...

Greetings