Detection: Cisco Secure Firewall - Remote Access Software Usage Traffic

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.

Search

 1`cisco_secure_firewall`
 2EventType=ConnectionEvent
 3
 4[
 5    
 6| inputlookup  remote_access_software
 7    
 8| search match_pattern!=""
 9    
10| rename match_pattern as ClientApplication
11    
12| table ClientApplication
13]
14
15
16| stats count min(_time) as firstTime
17              max(_time) as lastTime
18              values(dest_port) as dest_port
19              values(dest) as dest
20              values(transport) as transport
21              values(url) as url
22              values(rule) as rule
23
24  by src ClientApplication action
25
26
27| lookup local=t remote_access_software match_pattern AS ClientApplication OUTPUT app as signature, category, reference, description
28
29
30| `security_content_ctime(firstTime)`
31
32| `security_content_ctime(lastTime)`
33
34
35| `remote_access_software_usage_exceptions`
36
37
38| `cisco_secure_firewall___remote_access_software_usage_traffic_filter`

Data Source

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

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

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 "remote_access_software_usage_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

• Ransomware

• Cisco Secure Firewall Threat Defense Analytics

• Scattered Spider

• Scattered Lapsus$ Hunters

• Remote Monitoring and Management Software

• Command And Control

• Interlock Ransomware

• Insider Threat

Intermediate Findings

Threat Objects

References

• https://thedfirreport.com/2022/11/28/emotet-strikes-again-lnk-file-leads-to-domain-wide-ransomware/

• https://thedfirreport.com/2022/08/08/bumblebee-roasts-its-way-to-domain-admin/

• https://attack.mitre.org/techniques/T1219/

Detection Testing

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: 11