shellcraft

Shellcraft is a term used in computer security and exploit development to describe the programmatic construction of shellcode—small, executable machine code routines inserted into a running process to gain control or perform tasks. Rather than writing raw assembly by hand, researchers and developers use libraries and templates that generate architecture-specific code tailored to a given goal, such as spawning a shell or performing file and network operations.

One prominent implementation is the shellcraft module in the Pwntools framework. It provides a large collection of templates for many processor architectures that produce position-independent shellcode for common tasks. Users can request a shellcode fragment for a target architecture and task, and the library returns either assembly or raw machine bytes that can be linked into a payload.

Supported architectures include x86 and x86_64, ARM and AArch64, MIPS, PowerPC, and others. In addition to spawning a shell, shellcraft can generate code to execute system calls, read or write files, connect to or listen on network sockets, and perform simple string or I/O operations, often with options to avoid null bytes or to specify port numbers and addresses.

Shellcraft promotes rapid payload generation but depends on the underlying environment and the target's syscall interface. Generated code must be validated and tested in a controlled setting; writing or deploying shellcode without authorization is illegal in many jurisdictions.

In practice, shellcraft is used by researchers, exploit developers, and red-team practitioners as part of broader tooling for binary analysis, fuzzing, and security assessments.