Windows Ingress Tool Transfer Using Explorer
Description
The following analytic identifies instances where the Windows Explorer process (explorer.exe) is executed with a URL in its command line. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. This activity is significant because adversaries, such as those using DCRat malware, may abuse explorer.exe to open URLs with the default browser, which is an uncommon and suspicious behavior. If confirmed malicious, this technique could allow attackers to download and execute malicious payloads, leading to potential system compromise and further malicious activities.
- Type: Anomaly
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-05-18
- Author: Teoderick Contreras, Splunk
- ID: 76753bab-f116-4ea3-8fb9-89b638be58a9
Annotations
Kill Chain Phase
- Command and Control
NIST
- DE.AE
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name = explorer.exe OR Processes.original_file_name = explorer.exe) AND NOT (Processes.parent_process_name IN("userinit.exe", "svchost.exe")) Processes.process IN ("* http://*", "* https://*") by Processes.parent_process_name Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id Processes.dest Processes.user
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_ingress_tool_transfer_using_explorer_filter`
Macros
The SPL above uses the following Macros:
windows_ingress_tool_transfer_using_explorer_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
- Processes.dest
- Processes.user
- Processes.parent_process_name
- Processes.parent_process
- Processes.original_file_name
- Processes.process_name
- Processes.process
- Processes.process_id
- Processes.parent_process_path
- Processes.process_path
- Processes.parent_process_id
How To Implement
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes
node of the Endpoint
data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
Known False Positives
False positives may be present based on legitimate applications or third party utilities. Filter out any additional parent process names.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
25.0 | 50 | 50 | An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting to download a remote payload. |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
Test Dataset
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
source | version: 3