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Description

The following analytic detects suspicious system network configuration discovery activities, which may indicate an adversary's attempt to gather information about the network environment. Such actions typically involve commands or tools used to identify network interfaces, routing tables, and active connections. Detecting these activities is crucial, as they often precede more targeted attacks like lateral movement or data exfiltration. By identifying unusual or unauthorized network discovery efforts, this analytic helps security teams to swiftly detect and respond to potential reconnaissance operations, mitigating the risk of further compromise.

  • Type: Anomaly

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-09-04
  • Author: Teoderick Contreras, Splunk
  • ID: 5db16825-81bd-4923-a8d6-d6a13a59832a

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1016 System Network Configuration Discovery Discovery
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`linux_auditd` type=SYSCALL comm IN ("arp", "ifconfig", "ip", "netstat", "firewall-cmd", "ufw", "iptables", "ss", "route") 
| bucket _time span=15m 
| rename host as dest 
| stats dc(comm) as unique_commands, values(comm) as comm, values(exe) as exe, values(SYSCALL) as SYSCALL, values(UID) as UID, values(ppid) as ppid, values(pid) as pid, count, min(_time) as firstTime, max(_time) as lastTime by success dest 
| where unique_commands >= 4 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `linux_auditd_system_network_configuration_discovery_filter`

Macros

The SPL above uses the following Macros:

:information_source: linux_auditd_system_network_configuration_discovery_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • comm
  • exe
  • SYSCALL
  • UID
  • ppid
  • pid

How To Implement

To implement this detection, the process begins by ingesting auditd data, that consist SYSCALL, TYPE, EXECVE and PROCTITLE events, which captures command-line executions and process details on Unix/Linux systems. These logs should be ingested and processed using Splunk Add-on for Unix and Linux (https://splunkbase.splunk.com/app/833), which is essential for correctly parsing and categorizing the data. The next step involves normalizing the field names to match the field names set by the Splunk Common Information Model (CIM) to ensure consistency across different data sources and enhance the efficiency of data modeling. This approach enables effective monitoring and detection of linux endpoints where auditd is deployed

Known False Positives

Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
25.0 50 50 A SYSCALL - [$comm$] event was executed on host - [$dest$] to discover system network configuration.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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

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