Techniques
Sample rules
Windows Office Product Dropped Uncommon File
- source: splunk
- technicques:
- T1566.001
Description
The following analytic detects Microsoft Office applications dropping or creating executables or scripts on a Windows OS. It leverages process creation and file system events from the Endpoint data model to identify Office applications like Word or Excel generating files with extensions such as “.exe”, “.dll”, or “.ps1”. This behavior is significant as it is often associated with spear-phishing attacks where malicious files are dropped to compromise the host. If confirmed malicious, this activity could lead to code execution, privilege escalation, or persistent access, posing a severe threat to the environment.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
WHERE `process_office_products`
BY _time span=1h 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)`
| join process_guid, _time [
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem
WHERE Filesystem.file_name IN ("*.dll", "*.exe", "*.js", "*.pif", "*.ps1", "*.scr", "*.vbe", "*.vbs")
BY _time span=1h Filesystem.dest
Filesystem.file_create_time Filesystem.file_name Filesystem.process_guid
Filesystem.file_path
| `drop_dm_object_name(Filesystem)`
| fields _time dest file_create_time file_name file_path process_name process_path process process_guid]
| dedup file_create_time
| table dest, process_name, process, file_create_time, file_name, file_path, process_guid
| `windows_office_product_dropped_uncommon_file_filter`