ID | Technique | Tactic |
---|---|---|
T1203 | Exploitation for Client Execution | Execution |
T1059 | Command and Scripting Interpreter | Execution |
T1587.001 | Malware | Resource Development |
Detection: Cisco Secure Firewall - Possibly Compromised Host
EXPERIMENTAL DETECTION
This detection status is set to experimental. The Splunk Threat Research team has not yet fully tested, simulated, or built comprehensive datasets for this detection. As such, this analytic is not officially supported. If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
The following analytic highlights high-impact intrusion events assigned by Cisco Secure Firewall.
This detection leverages Cisco Secure Firewall Threat Defense logs and specifically the IntrusionEvent event type and Impact
field assigned by Cisco Secure Firewall looking for an impact score of 1 or 2. If confirmed malicious this may indicate a potential compromised host.
Search
1`cisco_secure_firewall` EventType=IntrusionEvent Impact IN (1,2)
2
3| stats count as TotalDetections values(signature_id) as signature_id
4 values(signature) as signature
5 values(rule) as rule
6 min(_time) as firstTime max(_time) as lastTime
7 by src_ip dest dest_port transport Impact app impact_desc class_desc MitreAttackGroups InlineResult InlineResultReason
8
9| `security_content_ctime(firstTime)`
10
11| `security_content_ctime(lastTime)`
12
13| `cisco_secure_firewall___possibly_compromised_host_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
Cisco Secure Firewall Threat Defense Intrusion Event | N/A | 'cisco:sfw:estreamer' |
'not_applicable' |
Macros Used
Name | Value |
---|---|
cisco_secure_firewall | sourcetype="cisco:sfw:estreamer" |
cisco_secure_firewall___possibly_compromised_host_filter | search * |
cisco_secure_firewall___possibly_compromised_host_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 IntrusionEvent 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 intrusion access policy must also be configured.
Known False Positives
False positives are directly related to their snort rules triggering and the firewall scoring. Apply additional filters if the rules are too noisy by disabling them or simply ignoring certain IP ranges that trigger it.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message:
A high impact IntrusionEvent was detected from $src_ip$ to $dest$.
Risk Object | Risk Object Type | Risk Score | Threat Objects |
---|---|---|---|
src_ip | system | 35 | signature |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | Not Applicable | N/A | N/A | N/A |
Unit | ❌ Failing | N/A | N/A |
N/A |
Integration | ❌ Failing | N/A | N/A |
N/A |
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