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tccontre
87 lines
3.7 KiB
YAML
87 lines
3.7 KiB
YAML
name: Linux Auditd Kernel Module Enumeration
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id: d1b088de-c47a-4572-9339-bdcc26493b32
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version: '3'
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date: '2024-12-17'
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author: Teoderick Contreras, Splunk
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status: production
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type: Anomaly
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description: The following analytic identifies the use of the 'kmod' process to list
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kernel modules on a Linux system. This detection leverages data from Linux Auditd,
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focusing on process names and command-line executions. While listing kernel modules
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is not inherently malicious, it can be a precursor to loading unauthorized modules
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using 'insmod'. If confirmed malicious, this activity could allow an attacker to
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load kernel modules, potentially leading to privilege escalation, persistence, or
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other malicious actions within the system.
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data_source:
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- Linux Auditd Syscall
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search: '`linux_auditd` type=SYSCALL comm=lsmod | rename host as dest | stats count
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min(_time) as firstTime max(_time) as lastTime by comm exe SYSCALL UID ppid pid
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success dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`
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| `linux_auditd_kernel_module_enumeration_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd
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data, that consist SYSCALL, TYPE, EXECVE and PROCTITLE events, which captures command-line
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executions and process details on Unix/Linux systems. These logs should be ingested
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and processed using Splunk Add-on for Unix and Linux (https://splunkbase.splunk.com/app/833),
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which is essential for correctly parsing and categorizing the data. The next step
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involves normalizing the field names to match the field names set by the Splunk
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Common Information Model (CIM) to ensure consistency across different data sources
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and enhance the efficiency of data modeling. This approach enables effective monitoring
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and detection of linux endpoints where auditd is deployed
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known_false_positives: False positives are present based on automated tooling or system
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administrative usage. Filter as needed.
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references:
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- https://man7.org/linux/man-pages/man8/kmod.8.html
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drilldown_searches:
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- name: View the detection results for - "$dest$"
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search: '%original_detection_search% | search dest = "$dest$"'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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- name: View risk events for the last 7 days for - "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$")
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starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime
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values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories)
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as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic)
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as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)`
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| `security_content_ctime(lastTime)`'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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tags:
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analytic_story:
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- Compromised Linux Host
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- XorDDos
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- Linux Rootkit
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asset_type: Endpoint
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confidence: 50
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impact: 30
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message: A SYSCALL - [$comm$] event was executed on host - [$dest$] to list kernel
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modules.
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mitre_attack_id:
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- T1082
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- T1014
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observable:
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- name: dest
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type: Endpoint
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role:
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- Victim
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product:
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- Splunk Enterprise
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- Splunk Enterprise Security
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- Splunk Cloud
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required_fields:
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- _time
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- comm
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- exe
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- SYSCALL
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- UID
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- ppid
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- pid
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risk_score: 15
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security_domain: endpoint
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tests:
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- name: True Positive Test
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attack_data:
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- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1082/linux_auditd_lsmod/linux_auditd_lsmod.log
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source: /var/log/audit/audit.log
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sourcetype: linux:audit
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update_timestamp: true
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