splApache-2.0from splunk/security_content

Windows Command Shell DCRat ForkBomb Payload

The following analytic detects the execution of a DCRat "forkbomb" payload, which spawns multiple cmd.exe processes that launch notepad.exe instances in quick succession. This detection leverages Endpoint Detection and Response (EDR) data, focusing on the rapid creation of cmd.exe and notepad.exe processes within a 30-second window. This activity is significant as it indicates a potential DCRat infection, a known Remote Access Trojan (RAT) with destructive capabilities. If confirmed malicious, this behavior could lead to system instability, resource exhaustion, and potential disruption of services.

Quality

FP risk

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Rule sourcedetections/endpoint/windows_command_shell_dcrat_forkbomb_payload.yml

| tstats `security_content_summariesonly` values(Processes.user) as user values(Processes.action) as action values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product dc(Processes.parent_process_id) as parent_process_id_count dc(Processes.process_id) as process_id_count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.parent_process_name= "cmd.exe" (Processes.process_name = "notepad.exe"
    OR
    Processes.original_file_name= "notepad.exe") Processes.parent_process = "*.bat*"
  BY Processes.parent_process_name Processes.process_name Processes.original_file_name
     Processes.parent_process Processes.dest Processes.user
     _time span=30s
| where parent_process_id_count>= 10 AND process_id_count >=10
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_command_shell_dcrat_forkbomb_payload_filter`