Techniques
Sample rules
Cisco NVM - Susp Script From Archive Triggering Network Activity
- source: splunk
- technicques:
- T1059.005
- T1204.002
Description
This analytic detects script execution (wscript.exe
or cscript.exe
) triggered from compressed files opened directly using
explorer.exe
, winrar.exe
, or 7zFM.exe
.
When a user double clicks on a “.js” file from within one of these compressed files. Its extracted temporally in the temp directory in folder with certain markers.
It leverages Cisco Network Visibility Module (NVM) flow data, in order to look for a specific parent/child relationship and an initiated network connection.
This behavior is exploited by threat actors such as Scarlet Goldfinch to deliver and run malicious scripts as an initial access technique.
Detection logic
`cisco_network_visibility_module_flowdata`
parent_process_name IN ("explorer.exe", "winrar.exe", "7zFM.exe")
process_name IN ("wscript.exe", "cscript.exe")
process_arguments = "*\\AppData\\Local\\Temp\\*"
process_arguments IN ("*\\rar*", "*\\7z*", "*.zip*")
| stats count min(_time) as firstTime max(_time) as lastTime
values(parent_process_arguments) as parent_process_arguments
values(process_arguments) as process_arguments
values(parent_process_hash) as parent_process_hash
values(process_hash) as process_hash
values(module_name_list) as module_name_list
values(module_hash_list) as module_hash_list
values(dest_port) as dest_port
values(aliul) as additional_logged_in_users_list
values(dest_hostname) as dest_hostname
by src dest parent_process_path parent_process_name parent_process_integrity_level process_path process_name process_integrity_level process_id transport
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| table
parent_process_integrity_level parent_process_name parent_process_path parent_process_arguments parent_process_hash
process_integrity_level process_path process_name process_arguments process_hash process_id
additional_logged_in_users_list module_name_list module_hash_list
src dest_hostname dest dest_port transport firstTime lastTime
| `cisco_nvm___susp_script_from_archive_triggering_network_activity_filter`