T1049.md

T1049 - System Network Connections Discovery

Description from ATT&CK

Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.

An adversary who gains access to a system that is part of a cloud-based environment may map out Virtual Private Clouds or Virtual Networks in order to determine what systems and services are connected. The actions performed are likely the same types of discovery techniques depending on the operating system, but the resulting information may include details about the networked cloud environment relevant to the adversary's goals. Cloud providers may have different ways in which their virtual networks operate.(Citation: Amazon AWS VPC Guide)(Citation: Microsoft Azure Virtual Network Overview)(Citation: Google VPC Overview)

Utilities and commands that acquire this information include netstat, "net use," and "net session" with Net. In Mac and Linux, netstat and lsof can be used to list current connections. who -a and w can be used to show which users are currently logged in, similar to "net session".

Atomic Tests

• Atomic Test #1 - System Network Connections Discovery

• Atomic Test #2 - System Network Connections Discovery with PowerShell

• Atomic Test #3 - System Network Connections Discovery Linux & MacOS

• Atomic Test #4 - System Discovery using SharpView

Atomic Test #1 - System Network Connections Discovery

Get a listing of network connections.

Upon successful execution, cmd.exe will execute netstat, net use and net sessions. Results will output via stdout.

Supported Platforms: Windows

Attack Commands: Run with command_prompt!

netstat
net use
net sessions

Atomic Test #2 - System Network Connections Discovery with PowerShell

Get a listing of network connections.

Upon successful execution, powershell.exe will execute get-NetTCPConnection. Results will output via stdout.

Supported Platforms: Windows

Attack Commands: Run with powershell!

Get-NetTCPConnection

Atomic Test #3 - System Network Connections Discovery Linux & MacOS

Get a listing of network connections.

Upon successful execution, sh will execute netstat and who -a. Results will output via stdout.

Supported Platforms: Linux, macOS

Attack Commands: Run with sh!

netstat
who -a

Dependencies: Run with sh!

Description: Check if netstat command exists on the machine

Check Prereq Commands:

if [ -x "$(command -v netstat)" ]; then exit 0; else exit 1; fi; 

Get Prereq Commands:

echo "Install netstat on the machine."; exit 1;

Atomic Test #4 - System Discovery using SharpView

Get a listing of network connections, domains, domain users, and etc.
sharpview.exe located in the bin folder, an opensource red-team tool. Upon successful execution, cmd.exe will execute sharpview.exe . Results will output via stdout.

Supported Platforms: Windows

Inputs:

Name	Description	Type	Default Value
SharpView_url	sharpview download URL	url	https://github.com/tevora-threat/SharpView/blob/b60456286b41bb055ee7bc2a14d645410cca9b74/Compiled/SharpView.exe?raw=true
SharpView	Path of the executable opensource redteam tool used for the performing this atomic.	path	PathToAtomicsFolder\T1049\bin\SharpView.exe
syntax	Arguements method used along with SharpView to get listing of network connections, domains, domain users, and etc.	String	"Invoke-ACLScanner", "Invoke-Kerberoast", "Find-DomainShare"

Attack Commands: Run with powershell! Elevation Required (e.g. root or admin)

$syntaxList = #{syntax}
foreach ($syntax in $syntaxList) {
#{SharpView} $syntax -}

Dependencies: Run with powershell!

Description: Sharpview.exe must exist on disk at specified location (#{SharpView})

Check Prereq Commands:

if (Test-Path #{SharpView}) {exit 0} else {exit 1} 

Get Prereq Commands:

New-Item -Type Directory (split-path #{SharpView}) -ErrorAction ignore | Out-Null
Invoke-WebRequest #{SharpView_url} -OutFile "#{SharpView}"