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add rename to auditd analytics
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detections/endpoint/linux_auditd_base64_decode_files.yml

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name: Linux Auditd Base64 Decode Files
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id: 5890ba10-4e48-4dc0-8a40-3e1ebe75e737
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version: 2
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date: '2024-09-30'
3+
version: 3
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date: '2025-01-15'
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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 detects suspicious Base64 decode operations that may indicate malicious activity, such as data exfiltration or execution of encoded commands. Base64 is commonly used to encode data for safe transmission, but attackers may abuse it to conceal malicious payloads. This detection focuses on identifying unusual or unexpected Base64 decoding processes, particularly when associated with critical files or directories. By monitoring these activities, the analytic helps uncover potential threats, enabling security teams to respond promptly and mitigate risks associated with encoded malware or unauthorized data access.
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data_source:
1010
- Linux Auditd Execve
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search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where LIKE(process_exec, "%base64%") AND (LIKE(process_exec, "%-d %") OR LIKE(process_exec, "% --d%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_base64_decode_files_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where LIKE(process_exec, "%base64%") AND (LIKE(process_exec, "%-d %") OR LIKE(process_exec, "% --d%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_base64_decode_files_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
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known_false_positives: Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.
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references:

detections/endpoint/linux_auditd_clipboard_data_copy.yml

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name: Linux Auditd Clipboard Data Copy
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id: 9ddfe470-c4d0-4e60-8668-7337bd699edd
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version: 2
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date: '2024-09-30'
3+
version: 3
4+
date: '2025-01-16'
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author: Teoderick Contreras, Splunk
66
status: production
77
type: Anomaly
88
description: The following analytic detects the use of the Linux 'xclip' command to copy data from the clipboard. It leverages Linux Auditd telemetry, focusing on process names and command-line arguments related to clipboard operations. This activity is significant because adversaries can exploit clipboard data to capture sensitive information such as passwords or IP addresses. If confirmed malicious, this technique could lead to unauthorized data exfiltration, compromising sensitive information and potentially aiding further attacks within the environment.
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data_source:
1010
- Linux Auditd Execve
11-
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where LIKE(process_exec, "%xclip%") AND (LIKE(process_exec, "%clipboard%") OR LIKE(process_exec, "%-o%") OR LIKE(process_exec, "%clip %") OR LIKE(process_exec, "%-selection %") OR LIKE(process_exec, "%sel %")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_clipboard_data_copy_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where LIKE(process_exec, "%xclip%") AND (LIKE(process_exec, "%clipboard%") OR LIKE(process_exec, "%-o%") OR LIKE(process_exec, "%clip %") OR LIKE(process_exec, "%-selection %") OR LIKE(process_exec, "%sel %")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_clipboard_data_copy_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
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known_false_positives: False positives may be present on Linux desktop as it may commonly be used by administrators or end users. Filter as needed.
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references:

detections/endpoint/linux_auditd_data_destruction_command.yml

Lines changed: 3 additions & 3 deletions
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name: Linux Auditd Data Destruction Command
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id: 4da5ce1a-f71b-4e71-bb73-c0a3c73f3c3c
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version: 2
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date: '2024-09-30'
3+
version: 3
4+
date: '2025-01-15'
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author: Teoderick Contreras, Splunk
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status: production
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type: TTP
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description: The following analytic detects the execution of a Unix shell command designed to wipe root directories on a Linux host. It leverages data from Linux Auditd, focusing on the 'rm' command with force recursive deletion and the '--no-preserve-root' option. This activity is significant as it indicates potential data destruction attempts, often associated with malware like Awfulshred. If confirmed malicious, this behavior could lead to severe data loss, system instability, and compromised integrity of the affected Linux host. Immediate investigation and response are crucial to mitigate potential damage.
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data_source:
1010
- Linux Auditd Execve
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search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where LIKE (process_exec, "%rm %") AND LIKE (process_exec, "% -rf %") AND LIKE (process_exec, "%--no-preserve-root%") | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_data_destruction_command_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where LIKE (process_exec, "%rm %") AND LIKE (process_exec, "% -rf %") AND LIKE (process_exec, "%--no-preserve-root%") | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_data_destruction_command_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
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known_false_positives: unknown
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references:

detections/endpoint/linux_auditd_data_transfer_size_limits_via_split.yml

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name: Linux Auditd Data Transfer Size Limits Via Split
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id: 4669561d-3bbd-44e3-857c-0e3c6ef2120c
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version: 2
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date: '2024-09-30'
3+
version: 3
4+
date: '2025-01-15'
55
author: Teoderick Contreras, Splunk
66
status: production
77
type: Anomaly
88
description: The following analytic detects suspicious data transfer activities that involve the use of the `split` syscall, potentially indicating an attempt to evade detection by breaking large files into smaller parts. Attackers may use this technique to bypass size-based security controls, facilitating the covert exfiltration of sensitive data. By monitoring for unusual or unauthorized use of the `split` syscall, this analytic helps identify potential data exfiltration attempts, allowing security teams to intervene and prevent the unauthorized transfer of critical information from the network.
99
data_source:
1010
- Linux Auditd Execve
11-
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where LIKE(process_exec, "%split %") AND LIKE(process_exec, "% -b %") | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_data_transfer_size_limits_via_split_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where LIKE(process_exec, "%split %") AND LIKE(process_exec, "% -b %") | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_data_transfer_size_limits_via_split_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
1313
known_false_positives: Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.
1414
references:

detections/endpoint/linux_auditd_database_file_and_directory_discovery.yml

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name: Linux Auditd Database File And Directory Discovery
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id: f616c4f3-bde9-41cf-856c-019b65f668bb
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version: 3
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date: '2024-09-30'
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version: 4
4+
date: '2025-01-15'
55
author: Teoderick Contreras, Splunk
66
status: production
77
type: Anomaly
88
description: The following analytic detects suspicious database file and directory discovery activities, which may signal an attacker attempt to locate and assess critical database assets on a compromised system. This behavior is often a precursor to data theft, unauthorized access, or privilege escalation, as attackers seek to identify valuable information stored in databases. By monitoring for unusual or unauthorized attempts to locate database files and directories, this analytic aids in early detection of potential reconnaissance or data breach efforts, enabling security teams to respond swiftly and mitigate the risk of further compromise.
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data_source:
1010
- Linux Auditd Execve
11-
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where (LIKE (process_exec, "%find%") OR LIKE (process_exec, "%grep%")) AND (LIKE (process_exec, "%.db%") OR LIKE (process_exec, "%.sql%") OR LIKE (process_exec, "%.sqlite%") OR LIKE (process_exec, "%.mdb%")OR LIKE (process_exec, "%.accdb%")OR LIKE (process_exec, "%.mdf%")OR LIKE (process_exec, "%.ndf%")OR LIKE (process_exec, "%.ldf%")OR LIKE (process_exec, "%.frm%")OR LIKE (process_exec, "%.idb%")OR LIKE (process_exec, "%.myd%")OR LIKE (process_exec, "%.myi%")OR LIKE (process_exec, "%.dbf%")OR LIKE (process_exec, "%.db2%")OR LIKE (process_exec, "%.dbc%")OR LIKE (process_exec, "%.fpt%")OR LIKE (process_exec, "%.ora%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_database_file_and_directory_discovery_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where (LIKE (process_exec, "%find%") OR LIKE (process_exec, "%grep%")) AND (LIKE (process_exec, "%.db%") OR LIKE (process_exec, "%.sql%") OR LIKE (process_exec, "%.sqlite%") OR LIKE (process_exec, "%.mdb%")OR LIKE (process_exec, "%.accdb%")OR LIKE (process_exec, "%.mdf%")OR LIKE (process_exec, "%.ndf%")OR LIKE (process_exec, "%.ldf%")OR LIKE (process_exec, "%.frm%")OR LIKE (process_exec, "%.idb%")OR LIKE (process_exec, "%.myd%")OR LIKE (process_exec, "%.myi%")OR LIKE (process_exec, "%.dbf%")OR LIKE (process_exec, "%.db2%")OR LIKE (process_exec, "%.dbc%")OR LIKE (process_exec, "%.fpt%")OR LIKE (process_exec, "%.ora%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_database_file_and_directory_discovery_filter`'
1212
how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
1313
known_false_positives: Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.
1414
references:

detections/endpoint/linux_auditd_file_and_directory_discovery.yml

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1,14 +1,14 @@
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name: Linux Auditd File And Directory Discovery
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id: 0bbfb79c-a755-49a5-a38a-1128d0a452f1
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version: 2
4-
date: '2024-09-30'
3+
version: 3
4+
date: '2025-01-15'
55
author: Teoderick Contreras, Splunk
66
status: production
77
type: Anomaly
88
description: The following analytic detects suspicious file and directory discovery activities, which may indicate an attacker's effort to locate sensitive documents and files on a compromised system. This behavior often precedes data exfiltration, as adversaries seek to identify valuable or confidential information for theft. By identifying unusual or unauthorized attempts to browse or enumerate files and directories, this analytic helps security teams detect potential reconnaissance or preparatory actions by an attacker, enabling timely intervention to prevent data breaches or unauthorized access.
99
data_source:
1010
- Linux Auditd Execve
11-
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where (LIKE (process_exec, "%find%") OR LIKE (process_exec, "%grep%")) AND (LIKE (process_exec, "%.tif%") OR LIKE (process_exec, "%.tiff%") OR LIKE (process_exec, "%.gif%") OR LIKE (process_exec, "%.jpeg%")OR LIKE (process_exec, "%.jpg%")OR LIKE (process_exec, "%.jif%")OR LIKE (process_exec, "%.jfif%")OR LIKE (process_exec, "%.jp2%")OR LIKE (process_exec, "%.jpx%")OR LIKE (process_exec, "%.j2k%")OR LIKE (process_exec, "%.j2c%")OR LIKE (process_exec, "%.fpx%")OR LIKE (process_exec, "%.pcd%")OR LIKE (process_exec, "%.png%")OR LIKE (process_exec, "%.flv%") OR LIKE (process_exec, "%.pdf%")OR LIKE (process_exec, "%.mp4%")OR LIKE (process_exec, "%.mp3%")OR LIKE (process_exec, "%.gifv%")OR LIKE (process_exec, "%.avi%")OR LIKE (process_exec, "%.mov%")OR LIKE (process_exec, "%.mpeg%")OR LIKE (process_exec, "%.wav%")OR LIKE (process_exec, "%.doc%")OR LIKE (process_exec, "%.docx%")OR LIKE (process_exec, "%.xls%")OR LIKE (process_exec, "%.xlsx%")OR LIKE (process_exec, "%.svg%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_file_and_directory_discovery_filter`'
11+
search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | rename comm as process_name | rename exe as process | where (LIKE (process_exec, "%find%") OR LIKE (process_exec, "%grep%")) AND (LIKE (process_exec, "%.tif%") OR LIKE (process_exec, "%.tiff%") OR LIKE (process_exec, "%.gif%") OR LIKE (process_exec, "%.jpeg%")OR LIKE (process_exec, "%.jpg%")OR LIKE (process_exec, "%.jif%")OR LIKE (process_exec, "%.jfif%")OR LIKE (process_exec, "%.jp2%")OR LIKE (process_exec, "%.jpx%")OR LIKE (process_exec, "%.j2k%")OR LIKE (process_exec, "%.j2c%")OR LIKE (process_exec, "%.fpx%")OR LIKE (process_exec, "%.pcd%")OR LIKE (process_exec, "%.png%")OR LIKE (process_exec, "%.flv%") OR LIKE (process_exec, "%.pdf%")OR LIKE (process_exec, "%.mp4%")OR LIKE (process_exec, "%.mp3%")OR LIKE (process_exec, "%.gifv%")OR LIKE (process_exec, "%.avi%")OR LIKE (process_exec, "%.mov%")OR LIKE (process_exec, "%.mpeg%")OR LIKE (process_exec, "%.wav%")OR LIKE (process_exec, "%.doc%")OR LIKE (process_exec, "%.docx%")OR LIKE (process_exec, "%.xls%")OR LIKE (process_exec, "%.xlsx%")OR LIKE (process_exec, "%.svg%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_file_and_directory_discovery_filter`'
1212
how_to_implement: To implement this detection, the process begins by ingesting auditd data, that consists of 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
1313
known_false_positives: Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.
1414
references:

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