Office Document Spawned Child Process To Download
Description
The following analytic identifies Office applications spawning child processes to download content via HTTP/HTTPS. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events where Office applications like Word or Excel initiate network connections, excluding common browsers. This activity is significant as it often indicates the use of malicious documents to execute living-off-the-land binaries (LOLBins) for payload delivery. If confirmed malicious, this behavior could lead to unauthorized code execution, data exfiltration, or further malware deployment, posing a severe threat to the organization's security.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-05-12
- Author: Teoderick Contreras, Splunk
- ID: 6fed27d2-9ec7-11eb-8fe4-aa665a019aa3
Annotations
ATT&CK
Kill Chain Phase
- Delivery
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name IN ("winword.exe","excel.exe","powerpnt.exe","mspub.exe","visio.exe","onenote.exe","onenotem.exe","onenoteviewer.exe","onenoteim.exe","msaccess.exe", "Graph.exe","winproj.exe") Processes.process IN ("*http:*","*https:*") NOT (Processes.original_file_name IN("firefox.exe", "chrome.exe","iexplore.exe","msedge.exe")) by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `office_document_spawned_child_process_to_download_filter`
Macros
The SPL above uses the following Macros:
office_document_spawned_child_process_to_download_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
Default browser not in the filter list.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
35.0 | 70 | 50 | Office document spawning suspicious child process on $dest$ |
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
- https://app.any.run/tasks/92d7ef61-bfd7-4c92-bc15-322172b4ebec/
- https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/trojanized-onenote-document-leads-to-formbook-malware/
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: 7