Echo Up

URL: https://pentest.ws/tools/echo-up

The Echo Up tool is useful for creating files on remote servers when you only have access to a terminal interface, either through a bash reverse shell or powershell remoting.

Echo Up

On the left side of the screen you can manually enter file contents or use the Load File button to read in a local file. As you type, the right side of the screen will create a list of shell commands to build the file on the remote server by using a number of techniques.

Base 64 Techniques

The following examples will encode "Hello World" and generate a "helloWorld.txt" file.

B64 bash

Linux - echos the payload to base64 and uses bash output redirection

echo -n 'SGVsbG8gV29ybGQ=' | base64 -d > helloWorld.txt

B64 cmd

Windows - uses certutil and cmd variables to generate a file

del /Q helloWorld.txt
del /Q froqwcxj
echo|set /p="SGVsbG8gV29ybGQ=" >> froqwcxj
certutil -decode froqwcxj helloWorld.txt
del /Q froqwcxj

B64 Powershell

Windows - powershell script using local variables and System.Convert

del helloWorld.txt
$boizakxl = @()
$boizakxl += [System.Convert]::FromBase64String("SGVsbG8gV29ybGQ=")
[Environment]::CurrentDirectory = (Get-Location -PSProvider FileSystem).ProviderPath
[System.IO.File]::WriteAllBytes("helloWorld.txt", $boizakxl)
Remove-Variable boizakxl

Quote Conversion Techniques

These examples parse the file contents converting single quotes to double quotes where needed. The file contents of the following examples is:

This is a "test" of the application's Echo Up feature.

Single Quoted

Wrap the file contents in single quotes and convert inner single quotes to a series of single quote, double quote, single quote, double quote, single quote.

echo 'This is a "test" of the application'"'"'s Echo Up feature.' > helloWorld.txt

Double Quoted

Wrap the file contents in double quotes and convert inner double quotes

echo "This is a "'"'"test"'"'" of the application's Echo Up feature." > helloWorld.txt

No Quotes

Do not convert the file contents.

echo This is a "test" of the application's Echo Up feature. > helloWorld.txt

Tier Availability

Echo Up is available on all tiers.