# T1547.009 - Boot or Logon Autostart Execution: Shortcut Modification

## Description from ATT&CK

> Adversaries may create or modify shortcuts that can execute a program during system boot or user login. Shortcuts or symbolic links are used to reference other files or programs that will be opened or executed when the shortcut is clicked or executed by a system startup process.
> 
> Adversaries may abuse shortcuts in the startup folder to execute their tools and achieve persistence.(Citation: Shortcut for Persistence ) Although often used as payloads in an infection chain (e.g. [Spearphishing Attachment](https://attack.mitre.org/techniques/T1566/001)), adversaries may also create a new shortcut as a means of indirection, while also abusing [Masquerading](https://attack.mitre.org/techniques/T1036) to make the malicious shortcut appear as a legitimate program. Adversaries can also edit the target path or entirely replace an existing shortcut so their malware will be executed instead of the intended legitimate program.
> 
> Shortcuts can also be abused to establish persistence by implementing other methods. For example, LNK browser extensions may be modified (e.g. [Browser Extensions](https://attack.mitre.org/techniques/T1176/001)) to persistently launch malware.

[Source](https://attack.mitre.org/techniques/T1547/009)

## Atomic Tests

- [Atomic Test #1: Shortcut Modification](#atomic-test-1-shortcut-modification)
- [Atomic Test #2: Create shortcut to cmd in startup folders](#atomic-test-2-create-shortcut-to-cmd-in-startup-folders)

### Atomic Test #1: Shortcut Modification

This test to simulate shortcut modification and then execute. example shortcut (*.lnk , .url) strings check with powershell;
gci -path "C:\Users" -recurse -include *.url -ea SilentlyContinue | Select-String -Pattern "exe" | FL.
Upon execution, calc.exe will be launched.

**Supported Platforms:** Windows

**auto_generated_guid:** `ce4fc678-364f-4282-af16-2fb4c78005ce`

#### Inputs

| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| shortcut_file_path | shortcut modified and execute | path | %temp%&#92;T1547.009_modified_shortcut.url|

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

```cmd
echo [InternetShortcut] > #{shortcut_file_path}
echo URL=C:\windows\system32\calc.exe >> #{shortcut_file_path}
#{shortcut_file_path}
```

#### Cleanup Commands

```cmd
del -f #{shortcut_file_path} >nul 2>&1
```
### Atomic Test #2: Create shortcut to cmd in startup folders

LNK file to launch CMD placed in startup folder. Upon execution, open File Explorer and browse to "%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\"
to view the new shortcut.

**Supported Platforms:** Windows

**auto_generated_guid:** `cfdc954d-4bb0-4027-875b-a1893ce406f2`

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

```powershell
$Shell = New-Object -ComObject ("WScript.Shell")
$ShortCut = $Shell.CreateShortcut("$env:APPDATA\Microsoft\Windows\Start Menu\Programs\Startup\T1547.009.lnk")
$ShortCut.TargetPath="cmd.exe"
$ShortCut.WorkingDirectory = "C:\Windows\System32";
$ShortCut.WindowStyle = 1;
$ShortCut.Description = "T1547.009.";
$ShortCut.Save()

$Shell = New-Object -ComObject ("WScript.Shell")
$ShortCut = $Shell.CreateShortcut("$env:ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\T1547.009.lnk")
$ShortCut.TargetPath="cmd.exe"
$ShortCut.WorkingDirectory = "C:\Windows\System32";
$ShortCut.WindowStyle = 1;
$ShortCut.Description = "T1547.009.";
$ShortCut.Save()
```

#### Cleanup Commands

```powershell
Remove-Item "$env:APPDATA\Microsoft\Windows\Start Menu\Programs\Startup\T1547.009.lnk" -ErrorAction Ignore
Remove-Item "$env:ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\T1547.009.lnk" -ErrorAction Ignore
```