LoFP LoFP / administrators may leverage dcom to start a process on remote systems, but this activity is usually limited to a small set of hosts or users.

Techniques

Sample rules

Remote Process Instantiation via DCOM and PowerShell

Description

The following analytic detects the execution of powershell.exe with arguments used to start a process on a remote endpoint by abusing the DCOM protocol, specifically targeting ShellExecute and ExecuteShellCommand. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and command-line executions. This activity is significant as it indicates potential lateral movement and remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code remotely, escalate privileges, and move laterally within the network, posing a severe security risk.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_powershell` (Processes.process="*Document.ActiveView.ExecuteShellCommand*" OR Processes.process="*Document.Application.ShellExecute*") by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `remote_process_instantiation_via_dcom_and_powershell_filter`

Remote Process Instantiation via DCOM and PowerShell Script Block

Description

The following analytic detects the execution of PowerShell commands that initiate a process on a remote endpoint via the DCOM protocol. It leverages PowerShell Script Block Logging (EventCode=4104) to identify the use of ShellExecute and ExecuteShellCommand. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this behavior could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.

Detection logic

`powershell` EventCode=4104 (ScriptBlockText="*Document.Application.ShellExecute*" OR ScriptBlockText="*Document.ActiveView.ExecuteShellCommand*") 
| fillnull 
| stats count min(_time) as firstTime max(_time) as lastTime by dest signature signature_id user_id vendor_product EventID Guid Opcode Name Path ProcessID ScriptBlockId ScriptBlockText 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `remote_process_instantiation_via_dcom_and_powershell_script_block_filter`