Cisco Secure Firewall - Malware File Downloaded
Description
The following analytic detects file downloads that were classified as malware by Cisco Secure Firewall Threat Defense. It relies on the SHA_Disposition field with a value of "Malware" and includes metadata such as file name, file_hash hash, and threat classification. This analytic is critical for surfacing file-based threats that are identified via Cisco's AMP or Threat Grid integrations. If confirmed malicious, this could indicate delivery of malware.
Query · spl
`cisco_secure_firewall` EventType=FileEvent SHA_Disposition="Malware" FileDirection="Download"
| lookup cisco_secure_firewall_filetype_lookup Name as FileType OUTPUT Description
| stats count min(_time) as firstTime max(_time) as lastTime
values(uri) as uri
values(ClientApplication) as ClientApplication
values(file_hash) as file_hash
by FileDirection dest src dest_port FileType app file_name ThreatName Description
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| table firstTime lastTime src dest dest_port FileDirection FileType Description uri file_name file_hash app ClientApplication ThreatName SHA_Disposition
| `cisco_secure_firewall___malware_file_downloaded_filter`
Implementation guide
This search requires Cisco Secure Firewall Threat Defense Logs, which
includes the FileEvent EventType. This search uses an input macro named cisco_secure_firewall.
We strongly recommend that you specify your environment-specific configurations
(index, source, sourcetype, etc.) for Cisco Secure Firewall Threat Defense logs. Replace the macro definition
with configurations for your Splunk environment. The search also uses a post-filter
macro designed to filter out known false positives.
The logs are to be ingested using the Splunk Add-on for Cisco Security Cloud (https://splunkbase.splunk.com/app/7404).
The malware & file access policy must also enable logging.
Known false positives
- Malicious verdicts could be outdated or incorrect due to retroactive threat intel.
Analyst notes
Known false positives: Malicious verdicts could be outdated or incorrect due to retroactive threat intel.