Powershell Loading Dotnet Into Memory Via System Reflection Assembly

Powershell Loading Dotnet Into Memory Via System Reflection Assembly

Description

The following analytic utilizes PowerShell Script Block Logging (EventCode=4104) to identify suspicious PowerShell execution. Script Block Logging captures the command sent to PowerShell, the full command to be executed. Upon enabling, logs will output to Windows event logs. Dependent upon volume, enable no critical endpoints or all. \ This analytic identifies the use of PowerShell loading .net assembly via reflection. This is commonly found in malicious PowerShell usage, including Empire and Cobalt Strike. In addition, the load( value may be modifed by removing ( and it will identify more events to review. \ During triage, review parallel processes using an EDR product or 4688 events. It will be important to understand the timeline of events around this activity. Review the entire logged PowerShell script block.

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Powershell Loading Dotnet Into Memory Via System Reflection Assembly Help

To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#ConfiguremoduleloggingforPowerShell.

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