Detection: Cisco Secure Firewall - Remote Access Software Usage Traffic

Updated Date: 2025-05-02 ID: ac54d39e-a75d-4f42-971d-006db3a0423a Author: Nasreddine Bencherchali, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects network traffic associated with known remote access software applications that are covered by Cisco Secure Firewall Application Detectors, such as AnyDesk, GoToMyPC, LogMeIn, and TeamViewer. It leverages Cisco Secure Firewall Threat Defense Connection Event. This activity is significant because adversaries often use remote access tools to maintain unauthorized access to compromised environments. If confirmed malicious, this activity could allow attackers to control systems remotely, exfiltrate data, or deploy additional malware, posing a severe threat to the organization's security.

 1`cisco_secure_firewall` EventType=ConnectionEvent
 2
 3| stats min(_time) as firstTime max(_time) as lastTime 
 4      values(dest_port) as dest_port
 5      values(dest) as dest
 6      values(transport) as transport
 7      values(url) as url
 8      values(rule) as rule
 9      count by src_ip ClientApplication action
10
11| `security_content_ctime(firstTime)`
12
13| `security_content_ctime(lastTime)`
14
15| lookup cisco_secure_firewall_appid_remote_mgmt_and_desktop_tools appName AS ClientApplication OUTPUT category, appDescription as Description
16
17| search category IN ("remote administration", "remote desktop control")
18
19| `remote_access_software_usage_exceptions`
20
21| `cisco_secure_firewall___remote_access_software_usage_traffic_filter`

Data Source

Name Platform Sourcetype Source
Cisco Secure Firewall Threat Defense Connection Event N/A 'cisco:sfw:estreamer' 'not_applicable'

Macros Used

Name Value
cisco_secure_firewall sourcetype="cisco:sfw:estreamer"
cisco_secure_firewall___remote_access_software_usage_traffic_filter search *
cisco_secure_firewall___remote_access_software_usage_traffic_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1219 Remote Access Tools Command And Control
Command and Control
DE.AE
CIS 13

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
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

This search requires Cisco Secure Firewall Threat Defense Logs, which includes the ConnectionEvent 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 access policy must also enable logging. The "exceptions" macro leverages both an Assets and Identities lookup, as well as a KVStore collection called "remote_software_exceptions" that lets you track and maintain device- based exceptions for this set of detections.

Known False Positives

It is possible that legitimate remote access software is used within the environment. Known false positives can be added to the remote_access_software_usage_exception.csv lookup to globally suppress these situations across all remote access content

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Traffic to known remote access software [$ClientApplication$] was detected from $src_ip$.

Risk Object Risk Object Type Risk Score Threat Objects
src_ip system 25 ClientApplication

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