ID | Technique | Tactic |
---|---|---|
T1203 | Exploitation for Client Execution | Execution |
T1105 | Ingress Tool Transfer | Command And Control |
Detection: 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.
Search
1`cisco_secure_firewall` EventType=FileEvent SHA_Disposition="Malware" FileDirection="Download"
2
3| lookup cisco_secure_firewall_filetype_lookup Name as FileType OUTPUT Description
4
5| stats count min(_time) as firstTime max(_time) as lastTime
6 values(uri) as uri
7 values(ClientApplication) as ClientApplication
8 values(file_hash) as file_hash
9 by FileDirection dest src_ip dest_port FileType app file_name ThreatName Description
10
11| `security_content_ctime(firstTime)`
12
13| `security_content_ctime(lastTime)`
14
15| table firstTime lastTime src_ip dest dest_port FileDirection FileType Description uri file_name file_hash app ClientApplication ThreatName SHA_Disposition
16
17| `cisco_secure_firewall___malware_file_downloaded_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
Cisco Secure Firewall Threat Defense File Event | N/A | 'cisco:sfw:estreamer' |
'not_applicable' |
Macros Used
Name | Value |
---|---|
cisco_secure_firewall | sourcetype="cisco:sfw:estreamer" |
cisco_secure_firewall___malware_file_downloaded_filter | search * |
cisco_secure_firewall___malware_file_downloaded_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Risk Event | True |
Implementation
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.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message:
File with Malware disposition downloaded from $dest$ over port $dest_port$ by $src_ip$
Risk Object | Risk Object Type | Risk Score | Threat Objects |
---|---|---|---|
src_ip | system | 30 | file_hash, file_name |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | not_applicable |
cisco:sfw:estreamer |
Integration | ✅ Passing | Dataset | not_applicable |
cisco:sfw:estreamer |
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: GitHub | Version: 1