Lots of different approaches: To figure out if a process is ptraced the process can try to ptrace itself. An executable can only get ptraced once at a time, so

Lots of different approaches: To figure out if a process is ptraced the process can try to ptrace itself. An executable can only get ptraced once at a time, so the second call to ptrace will fail. Of course you can workaround that check by patching the code so that it doesn't call ptrace. Breakpoints are also easy to spot. Just look for 0xCC in the memory. But of course there are also multiple ways to work around those checks (such as using harder to detect hardware breakpoints instead of software breakpoints).