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Description

The following analytic identifies a potentially suspicious execution of the 'pkgmgr' process involving the use of an XML input file for package management. The 'pkgmgr' process, though deprecated in modern Windows systems, was historically used for managing packages. The presence of an XML input file raises concerns about the nature of the executed command and its potential impact on the system. Due to the deprecated status of 'pkgmgr' and the involvement of an XML file, this activity warrants careful investigation. XML files are commonly used for configuration and data exchange, making it crucial to ascertain the intentions and legitimacy of the command. To ensure system security, it is recommended to use up-to-date package management utilities, such as DISM or PowerShell's PackageManagement module, and exercise caution when executing commands involving potentially sensitive operations or files.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-07-26
  • Author: Teoderick Contreras, Splunk
  • ID: cce58e2c-988a-4319-9390-0daa9eefa3cd

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1548.002 Bypass User Account Control Privilege Escalation, Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where  Processes.process_name = pkgmgr.exe Processes.process = "*.xml*" NOT(Processes.parent_process_path IN("*:\\windows\\system32\\*", "*:\\windows\\syswow64\\*", "*:\\Program Files*")) by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process_path Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_bypass_uac_via_pkgmgr_tool_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_bypass_uac_via_pkgmgr_tool_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
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

False positives may be present on recent Windows Operating Systems. Filtering may be required based on process_name. In addition, look for non-standard, unsigned, module loads into LSASS. If query is too noisy, modify by adding Endpoint.processes process_name to query to identify the process making the modification.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
9.0 30 30 A pkgmgr.exe executed with package manager xml input file on $dest$

: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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