/**
Copyright © 2016-2019 Odzhan. All Rights Reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY AUTHORS "AS IS" AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. */
#if defined(_WIN32) || defined(_WIN64)
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0502
#endif
#define WIN
#ifndef _WINSOCKAPI_
#define _WINSOCKAPI_
#endif
#include <windows.h>
#include <shlwapi.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#define close closesocket
#define SHUT_RDWR SD_BOTH
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "shlwapi.lib")
#else
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <signal.h>
#include <fcntl.h>
#endif
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <sys/stat.h>
#define RSC_CLIENT 0
#define RSC_SERVER 1
#define RSC_EXEC 2
#define RSC_SEND 0
#define RSC_RECV 1
#define DEFAULT_PORT "4444"
// structure for parameters
typedef struct _args_t {
int s, r;
char *port, *address, *file;
#ifdef WIN
char *modules;
#endif
int port_nbr, ai_family, mode, sim, tx_mode, ai_addrlen, dbg;
struct sockaddr *ai_addr;
struct sockaddr_in v4;
struct sockaddr_in6 v6;
char ip[INET6_ADDRSTRLEN];
uint32_t code_len;
void *code;
} args_t;
#ifdef WIN
/**F*****************************************************************/
void xstrerror (char *fmt, ...)
/**
* PURPOSE : Display windows error
*
* RETURN : Nothing
*
* NOTES : None
*
*F*/
{
char *error=NULL;
va_list arglist;
char buffer[2048];
DWORD dwError=GetLastError();
va_start (arglist, fmt);
wvnsprintf (buffer, sizeof(buffer) - 1, fmt, arglist);
va_end (arglist);
if (FormatMessage (
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPSTR)&error, 0, NULL))
{
printf ("[ %s : %s\n", buffer, error);
LocalFree (error);
} else {
printf ("[ %s : %i\n", buffer, dwError);
}
}
#else
#define xstrerror printf
#endif
char *addr2ip(args_t *p)
{
void *src;
#ifdef WIN
DWORD ip_size=INET6_ADDRSTRLEN;
WSAAddressToString (p->ai_addr, p->ai_addrlen,
NULL, (char*)p->ip, &ip_size);
#else
if (p->ai_family==AF_INET) {
src=(void*)&p->v4.sin_addr;
} else {
src=(void*)&p->v6.sin6_addr;
}
inet_ntop(p->ai_family, src, p->ip, INET6_ADDRSTRLEN);
#endif
return p->ip;
}
int init_network (args_t *p)
/**
* PURPOSE : initialize winsock for windows, resolve network address
*
* RETURN : 1 for okay else 0
*
* NOTES : None
*
*F*/
{
struct addrinfo *list=NULL, *e=NULL;
struct addrinfo hints;
int r, t;
// initialize winsock if windows
#ifdef WIN
WSADATA wsa;
WSAStartup (MAKEWORD (2, 0), &wsa);
#endif
r=0;
// set network address length to zero
p->ai_addrlen = 0;
// if no address supplied
if (p->address==NULL)
{
// is it ipv4?
if (p->ai_family==AF_INET) {
p->v4.sin_family = AF_INET;
p->v4.sin_port = htons((u_short)p->port_nbr);
p->v4.sin_addr.s_addr = INADDR_ANY;
p->ai_addr = (struct sockaddr*)&p->v4;
p->ai_addrlen = sizeof (struct sockaddr_in);
} else {
// else it's ipv6
p->v6.sin6_family = AF_INET6;
p->v6.sin6_port = htons((u_short)p->port_nbr);
p->v6.sin6_addr = in6addr_any;
p->ai_addr = (struct sockaddr*)&p->v6;
p->ai_addrlen = sizeof (struct sockaddr_in6);
}
} else {
memset (&hints, 0, sizeof (hints));
hints.ai_flags = AI_PASSIVE;
hints.ai_family = p->ai_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
// get all network addresses
t=getaddrinfo (p->address, p->port, &hints, &list);
if (t == 0)
{
for (e=list; e!=NULL; e=e->ai_next)
{
// copy to ipv4 structure
if (p->ai_family==AF_INET) {
memcpy (&p->v4, e->ai_addr, e->ai_addrlen);
p->ai_addr = (struct sockaddr*)&p->v4;
} else {
// ipv6 structure
memcpy (&p->v6, e->ai_addr, e->ai_addrlen);
p->ai_addr = (struct sockaddr*)&p->v6;
}
// assign size of structure
p->ai_addrlen = e->ai_addrlen;
break;
}
freeaddrinfo (list);
} else {
xstrerror ("getaddrinfo");
}
}
return p->ai_addrlen;
}
void debug(void *bin)
{
//
//__builtin_trap();
//raise(SIGTRAP);
}
// allocate read/write and executable memory
// copy data from p->code and execute
void xcode(args_t *p)
{
void *bin;
int i;
int fd[2048];
if (p->code_len == 0) {
printf("[ no code to execute.\n");
return;
}
printf ("[ executing code...");
#ifdef WIN
bin=VirtualAlloc (0, p->code_len,
MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
#else
bin=mmap (0, p->code_len,
PROT_EXEC | PROT_WRITE | PROT_READ,
MAP_ANON | MAP_PRIVATE, -1, 0);
#endif
if (bin!=NULL)
{
memcpy (bin, p->code, p->code_len);
// create file/socket descriptors to simulate real system
// created interesting results on openbsd with limits
// to how many files could be open at once..
//
if (p->sim) {
#ifndef WIN
for (i=0; i<p->sim && p->sim<2048; i++) {
fd[i]=socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
}
#else
// todo
for (i=0; i<p->sim && p->sim<2048; i++) {
}
#endif
}
// debug the code?
if (p->dbg) {
#if defined(_WIN32) || defined(_WIN64)
DebugBreak();
#else
raise(SIGTRAP);
#endif
}
// execute
((void(*)())bin)();
printf("OK!\n");
if (p->sim) {
#ifndef WIN
// close all descriptors
for (i=0; i<p->sim && p->sim<2048; i++) {
close(fd[i]);
}
#else
// todo
#endif
}
#ifdef WIN
VirtualFree (bin, 0, MEM_RELEASE | MEM_DECOMMIT);
#else
munmap (bin, p->code_len);
#endif
}
}
void send_data(args_t *p, int s) {
FILE *fd;
int outlen, len, opt;
uint32_t sum;
uint8_t buf[BUFSIZ];
// open file for read in binary mode
printf ("[ opening %s for read\n", p->file);
fd = fopen(p->file, "rb");
if (fd != NULL)
{
// send contents of file
printf ("[ sending data\n");
for (;;) {
// read block
outlen = fread(buf, sizeof(uint8_t), BUFSIZ, fd);
// zero or less indicates EOF
if (outlen <= 0) break;
// send contents
for (sum=0; sum<outlen; sum += len) {
len=send (s, &buf[sum], outlen - sum, 0);
if (len <= 0) break;
}
p->code_len += sum;
if (outlen != sum) break;
}
printf ("[ sent %i bytes\n", p->code_len);
fclose(fd);
}
}
void recv_data(args_t *p, int s) {
int opt, r;
fd_set fds;
struct timeval tv;
void *pv;
p->code_len = 0;
p->code = malloc(BUFSIZ);
// set to non-blocking mode
#ifdef WIN
opt=1;
ioctlsocket (s, FIONBIO, (u_long*)&opt);
#else
opt=fcntl(s, F_GETFL, 0);
fcntl(s, F_SETFL, opt | O_NONBLOCK);
#endif
// keep reading until remote disconnects or we run out of memory
printf ("[ receiving data\n");
for (;;) {
FD_ZERO(&fds);
FD_SET(s, &fds);
tv.tv_sec = 5;
tv.tv_usec = 0;
r = select(FD_SETSIZE, &fds, 0, 0, &tv);
if (r <= 0) {
printf ("[ waiting for data timed out or failed\n");
break;
}
// receive a block
r = recv(s, (uint8_t*)p->code + p->code_len, BUFSIZ, 0);
if (r <= 0) break;
p->code_len += r;
// resize buffer
pv = realloc(p->code, p->code_len + BUFSIZ);
// on error, free pointer
if(pv == NULL) {
p->code_len = 0;
free(p->code);
p->code = NULL;
printf("[ error: out of memory.\n");
break;
}
p->code = pv;
}
if(p->code_len != 0) {
printf ("[ received %i bytes\n", p->code_len);
}
}
//
int ssr (args_t *p)
/**
* PURPOSE : send a shellcode or receive one from remote system and execute it
*
* RETURN : 0 or length of shellcode sent/received
*
* NOTES : None
*
*F*/
{
int s, opt, r, t;
fd_set fds;
struct timeval tv;
p->code_len=0;
// create socket
printf ("[ creating socket\n");
s = socket(p->ai_family, SOCK_STREAM, IPPROTO_TCP);
if (s < 0) return 0;
// ensure we can reuse socket
t=1;
setsockopt (s, SOL_SOCKET, SO_REUSEADDR, (char*)&t, sizeof (t));
// bind to port
printf ("[ binding to port %s\n", p->port);
r = bind(s, p->ai_addr, p->ai_addrlen);
if (r == 0) {
// listen
r = listen (s, 1);
if (r == 0) {
printf ("[ waiting for connections on %s\n", addr2ip(p));
if (r == 0) {
t = accept(s, p->ai_addr, &p->ai_addrlen);
printf ("[ accepting connection from %s\n", addr2ip(p));
if (t > 0) {
if (p->tx_mode == RSC_SEND) {
send_data(p, t);
} else {
recv_data(p, t);
xcode(p);
}
}
}
// close socket to peer
shutdown(t, SHUT_RDWR);
close(t);
} else {
perror("listen");
}
} else {
perror("bind");
}
// close listening socket
shutdown(s, SHUT_RDWR);
close(s);
return p->code_len;
}
/**F*****************************************************************/
int csr (args_t *p)
/**
* PURPOSE : opens connection to remote system and sends shellcode
*
* RETURN : 0 or 1
*
* NOTES : None
*
*F*/
{
int s, r, opt;
fd_set fds;
struct timeval tv;
printf ("[ creating socket\n");
s = socket(p->ai_family, SOCK_STREAM, IPPROTO_TCP);
if (s < 0) return 0;
// try connect to remote
printf ("[ connecting to %s\n", addr2ip(p));
r = connect(s, p->ai_addr, p->ai_addrlen);
if (r == 0) {
if (p->tx_mode==RSC_SEND) {
send_data(p, s);
} else {
recv_data(p, s);
xcode(p);
}
} else {
xstrerror("connect");
}
printf ("[ closing connection\n");
shutdown(s, SHUT_RDWR);
close(s);
return 1;
}
/**F*****************************************************************/
void xfile(args_t *p)
/**
* PURPOSE : read contents of shellcode and attempt to execute it locally
*
* RETURN : Nothing
*
* NOTES : None
*
*F*/
{
FILE *fd;
int len;
void *pv;
p->code_len = 0;
p->code = NULL;
printf ("[ reading code from %s\n", p->file);
fd = fopen(p->file, "rb");
if (fd == NULL) {
xstrerror("fopen(\"%s\")", p->file);
return;
}
// read contents of file
for (;;) {
// first loop? allocate block
if(p->code == NULL) {
p->code = malloc(BUFSIZ);
}
// read a block of data
len = fread((uint8_t*)p->code + p->code_len, sizeof(uint8_t), BUFSIZ, fd);
if (len <= 0) break;
p->code_len += len;
// resize buffer for next read
pv = realloc(p->code, p->code_len + BUFSIZ);
if(pv == NULL) {
p->code_len = 0;
free(p->code);
p->code = NULL;
printf("[ error: out of memory!.\n");
break;
}
p->code = pv;
}
fclose(fd);
if(p->code_len != 0) {
xcode(p);
}
}
#ifdef WIN
void load_modules(char *names) {
HMODULE mod;
char *p = strtok(names, ";,");
while (p != NULL) {
printf ("[ loading %s...", p);
mod = LoadLibrary(p);
printf ("%s\n", mod==NULL ? "FAILED" : "OK");
p = strtok(NULL, ";,");
}
}
#endif
/**F*****************************************************************/
void usage (void) {
printf ("\n usage: runsc <address> [options]\n");
printf ("\n -4 Use IP version 4 (default)");
printf ("\n -6 Use IP version 6");
printf ("\n -l Listen mode (required when listening on specific interface)");
#ifdef WIN
printf ("\n -m <dll> Loads DLL modules. Each one separated by comma or semi-colon");
#endif
printf ("\n -f <file> Read PIC from <file>");
printf ("\n -s <count> Simulate real process by creating file descriptors");
printf ("\n -p <number> Port number to use (default is %s)", DEFAULT_PORT);
printf ("\n -x Execute PIC (requires -f)");
printf ("\n\n Press any key to continue . . .");
getchar ();
exit (0);
}
/**F*****************************************************************/
char* getparam (int argc, char *argv[], int *i) {
int n=*i;
if (argv[n][2] != 0) {
return &argv[n][2];
}
if ((n+1) < argc) {
*i=n+1;
return argv[n+1];
}
printf ("[ %c%c requires parameter\n", argv[n][0], argv[n][1]);
exit (0);
}
void parse_args (args_t *p, int argc, char *argv[]) {
int i;
char opt;
// for each argument
for (i=1; i<argc; i++)
{
// is this option?
if (argv[i][0]=='-' || argv[i][1]=='/')
{
// get option value
opt=argv[i][1];
switch (opt)
{
case '4':
p->ai_family=AF_INET;
break;
case '6': // use ipv6 (default is ipv4)
p->ai_family=AF_INET6;
break;
case 'x': // execute PIC, requires -f
p->mode=RSC_EXEC;
break;
case 'd': // debug the code
p->dbg=1;
break;
case 'f': // file
p->file=getparam(argc, argv, &i);
break;
case 'l': // listen for incoming connections
p->mode=RSC_SERVER;
break;
#ifdef WIN
case 'm': // windows only, loads modules required by shellcode
p->modules = getparam(argc, argv, &i);
break;
#endif
case 's': // create file descriptors before execution
p->sim=atoi(getparam(argc, argv, &i));
break;
case 'p': // port number
p->port=getparam(argc, argv, &i);
p->port_nbr=atoi(p->port);
break;
case '?': // display usage
case 'h':
usage ();
break;
default:
printf ("[ unknown option %c\n", opt);
usage();
break;
}
} else {
// assume it's hostname or ip
p->address=argv[i];
p->mode=RSC_CLIENT;
}
}
}
int main (int argc, char *argv[]) {
args_t args;
struct stat st;
#ifdef WIN
//
PVOID OldValue=NULL;
WSADATA wsa;
//Wow64DisableWow64FsRedirection (&OldValue);
LoadLibrary("ws2_32");
LoadLibrary("advapi32");
WSAStartup(MAKEWORD(2,0), &wsa);
#endif
setbuf(stdout, NULL);
setbuf(stderr, NULL);
memset (&args, 0, sizeof(args));
// set default parameters
args.address = NULL;
args.file = NULL;
args.ai_family = AF_INET;
args.port = DEFAULT_PORT;
args.port_nbr = atoi(args.port);
args.mode = -1;
args.tx_mode = -1;
args.sim = 0;
args.dbg = 0;
printf ("\n[ run shellcode v0.2\n");
parse_args(&args, argc, argv);
// check if we have file parameter and it accessible
if (args.file!=NULL) {
if (stat (args.file, &st)) {
printf ("[ unable to access %s\n", args.file);
return 0;
}
}
#ifdef WIN
if (args.modules != NULL) {
load_modules(args.modules);
}
#endif
// if mode is executing
if (args.mode == RSC_EXEC) {
if (args.file != NULL) {
xfile(&args);
return 0;
} else {
printf ("\n[ you've used -x without supplying file with -f");
return 0;
}
}
if (init_network(&args)) {
// if no file specified, we receive and execute data
args.tx_mode = (args.file==NULL) ? RSC_RECV : RSC_SEND;
// if mode is -1, we listen for incoming connections
if (args.mode == -1) {
args.mode=RSC_SERVER;
}
// if no file specified, set to receive one
if (args.tx_mode == -1) {
args.tx_mode = RSC_RECV;
}
if (args.mode == RSC_SERVER) {
ssr (&args);
} else {
csr (&args);
}
}
if(args.code_len != 0) {
free(args.code);
}
return 0;
}