Detection: Cisco ASA - Packet Capture Activity

Updated Date: 2025-11-18 ID: 7e9c3f8a-4b2d-4c5e-9a1f-6d8e5b3c2a9f Author: Nasreddine Bencherchali, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

This analytic detects execution of packet capture commands on Cisco ASA devices via CLI or ASDM. Adversaries may abuse the built-in packet capture functionality to perform network sniffing, intercept credentials transmitted over the network, capture sensitive data in transit, or gather intelligence about network traffic patterns and internal communications. Packet captures can reveal usernames, passwords, session tokens, and confidential business data. The detection monitors for command execution events (message ID 111008 or 111010) containing "capture" commands, which are used to initiate packet capture sessions on specific interfaces or for specific traffic patterns on the ASA device. Investigate unauthorized packet capture activities, especially captures targeting sensitive interfaces (internal network segments, DMZ), captures configured to capture large volumes of traffic, captures with suspicious filter criteria, captures initiated by non-administrative accounts, or captures during unusual hours.

Search

 1`cisco_asa`
 2message_id IN (111008, 111010)
 3command IN ("capture *")
 4
 5| fillnull
 6
 7| stats count
 8        earliest(_time) as firstTime
 9        latest(_time) as lastTime
10        values(user) as user
11        values(action) as action
12        values(message_id) as message_id
13        values(command) as command
14        values(src_ip) as src_ip
15        values(process_name) as process_name
16  by host
17
18| `security_content_ctime(firstTime)`
19
20| `security_content_ctime(lastTime)`
21
22| `cisco_asa___packet_capture_activity_filter`

Data Source

Name	Platform	Sourcetype	Source
Cisco ASA Logs	Other	`'cisco:asa'`	`'not_applicable'`

Macros Used

Name	Value
cisco_asa	`sourcetype=cisco:asa`
cisco_asa___packet_capture_activity_filter	`search *`

cisco_asa___packet_capture_activity_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
T1040	Network Sniffing	Credential Access
T1557	Adversary-in-the-Middle	Discovery

Exploitation

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 ASA syslog data to be ingested into Splunk via the Cisco Security Cloud TA. To ensure this detection works effectively, configure your ASA and FTD devices to generate and forward message ID 111008 and 111010. If your logging level is set to 'notifications' or higher, these messages should already be included, else we recommend setting an event list that keeps the severity level you are using and adding the message IDs 111008 and 111010. You can find specific instructions on how to set this up here : https://www.cisco.com/c/en/us/support/docs/security/pix-500-series-security-appliances/63884-config-asa-00.html. You can also change the severity level of the above message id's to the syslog level you have currently enabled using the logging message syslog_id level severity_level command in global configuration mode. For more information, see Change the Severity Level of a Syslog Message : https://www.cisco.com/c/en/us/td/docs/security/asa/asa922/configuration/general/asa-922-general-config/monitor-syslog.html#ID-2121-000006da

Known False Positives

Admins use packet captures for troubleshooting, performance monitoring, or security investigations. Verify against change management. Filter known admin accounts during maintenance windows.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

User $user$ executed packet capture command $command$ on Cisco ASA host $host$, potentially for network sniffing activity.

Risk Object	Risk Object Type	Risk Score	Threat Objects
user	user	50	command
host	system	50	command

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`not_applicable`	`cisco:asa`
Integration	✅ Passing	Dataset	`not_applicable`	`cisco:asa`

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