T1133 - External Remote Services
Description from ATT&CK (opens in a new tab)
Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management (opens in a new tab) and VNC (opens in a new tab) can also be used externally.(Citation: MacOS VNC software for Remote Desktop)
Access to Valid Accounts (opens in a new tab) to use the service is often a requirement, which could be obtained through credential pharming or by obtaining the credentials from users after compromising the enterprise network.(Citation: Volexity Virtual Private Keylogging) Access to remote services may be used as a redundant or persistent access mechanism during an operation.
Access may also be gained through an exposed service that doesn’t require authentication. In containerized environments, this may include an exposed Docker API, Kubernetes API server, kubelet, or web application such as the Kubernetes dashboard.(Citation: Trend Micro Exposed Docker Server)(Citation: Unit 42 Hildegard Malware)
Atomic Tests
Atomic Test #1 - Running Chrome VPN Extensions via the Registry 2 vpn extension
Running Chrome VPN Extensions via the Registry install 2 vpn extension, please see "T1133\src\list of vpn extension.txt" to view complete list
Supported Platforms: Windows
auto_generated_guid: 4c8db261-a58b-42a6-a866-0a294deedde4
Inputs:
| Name | Description | Type | Default Value |
|---|---|---|---|
| chrome_url | chrome installer download URL | url | https://dl.google.com/tag/s/appguid%3D%7B8A69D345-D564-463C-AFF1-A69D9E530F96%7D%26iid%3D%7BFD62DDBC-14C6-20BD-706F-C7744738E422%7D%26lang%3Den%26browser%3D3%26usagestats%3D0%26appname%3DGoogle%2520Chrome%26needsadmin%3Dprefers%26ap%3Dx64-stable-statsdef_1%26installdataindex%3Dempty/chrome/install/ChromeStandaloneSetup64.exe (opens in a new tab) |
| extension_id | chrome extension id | string | "fcfhplploccackoneaefokcmbjfbkenj", "fdcgdnkidjaadafnichfpabhfomcebme" |
Attack Commands: Run with powershell! Elevation Required (e.g. root or admin)
$extList = #{extension_id}
foreach ($extension in $extList) {
New-Item -Path HKLM:\Software\Wow6432Node\Google\Chrome\Extensions\$extension -Force
New-ItemProperty -Path "HKLM:\Software\Wow6432Node\Google\Chrome\Extensions\$extension" -Name "update_url" -Value "https://clients2.google.com/service/update2/crx" -PropertyType "String" -Force}
Start chrome
Start-Sleep -Seconds 30
Stop-Process -Name "chrome"Cleanup Commands:
$extList = #{extension_id}
foreach ($extension in $extList) {
Remove-Item -Path "HKLM:\Software\Wow6432Node\Google\Chrome\Extensions\$extension" -ErrorAction Ignore}Dependencies: Run with powershell!
Description: Chrome must be installed
Check Prereq Commands:
if ((Test-Path "C:\Program Files\Google\Chrome\Application\chrome.exe") -Or (Test-Path "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe")) {exit 0} else {exit 1}Get Prereq Commands:
New-Item -Type Directory "PathToAtomicsFolder\..\ExternalPayloads\" -ErrorAction Ignore -Force | Out-Null
Invoke-WebRequest -OutFile "PathToAtomicsFolder\..\ExternalPayloads\ChromeStandaloneSetup64.exe" #{chrome_url}
Start-Process "PathToAtomicsFolder\..\ExternalPayloads\ChromeStandaloneSetup64.exe" /S