Techniques
Sample rules
Suspicious writes to windows Recycle Bin
- source: splunk
- technicques:
- T1036
Description
The following analytic detects when a process other than explorer.exe writes to the Windows Recycle Bin. It leverages the Endpoint.Filesystem and Endpoint.Processes data models in Splunk to identify any process writing to the “$Recycle.Bin” file path, excluding explorer.exe. This activity is significant because it may indicate an attacker attempting to hide their actions, potentially leading to data theft, ransomware, or other malicious outcomes. If confirmed malicious, this behavior could allow an attacker to persist in the environment and evade detection by security tools.
Detection logic
| tstats prestats=t `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes where Processes.process_name != "explorer.exe" by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| tstats prestats=t append=t `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_path = "*$Recycle.Bin*" by Filesystem.action Filesystem.dest Filesystem.file_access_time Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time Filesystem.file_name Filesystem.file_path Filesystem.file_acl Filesystem.file_size Filesystem.process_guid Filesystem.process_id Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| table action dest original_file_name parent_process parent_process_exec parent_process_guid parent_process_id parent_process_name parent_process_path process process_exec process_guid process_hash process_id process_integrity_level process_name process_path user user_id vendor_product file_access_time file_create_time file_hash file_modify_time file_name file_path file_acl file_size firstTime lastTime
| stats values(action) as action values(dest) as dest values(original_file_name) as original_file_name values(parent_process) as parent_process values(parent_process_exec) as parent_process_exec values(parent_process_guid) as parent_process_guid values(parent_process_id) as parent_process_id values(parent_process_name) as parent_process_name values(parent_process_path) as parent_process_path values(process) as process values(process_exec) as process_exec values(process_hash) as process_hash values(process_id) as process_id values(process_integrity_level) as process_integrity_level values(process_name) as process_name values(process_path) as process_path values(user) as user values(user_id) as user_id values(vendor_product) as vendor_product values(file_access_time) as file_access_time values(file_create_time) as file_create_time values(file_hash) as file_hash values(file_modify_time) as file_modify_time values(file_name) as file_name values(file_path) as file_path values(file_acl) as file_acl values(file_size) as file_size by process_guid
| where isnotnull(process_name) AND isnotnull(file_name)
| `suspicious_writes_to_windows_recycle_bin_filter`