Detection: Windows Azure Storage Utility Execution Via CLI

Description

This analytic detects the execution of Azure Storage utilities such as AzCopy and Storage Explorer via the CLI. These tools enable large-scale data transfers over trusted cloud channels, allowing malicious activity to blend with legitimate traffic and evade traditional network defenses. Adversaries may leverage them post-compromise to stage or extract sensitive data from endpoints. While legitimate administrative use is expected, anomalous execution patterns, unexpected users, or unusual parent processes should be treated as potential indicators of compromise and investigated promptly.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8Processes.process_name IN (
 9    "AzCopy.exe",
10    "StorageExplorer.exe"
11)
12
13by Processes.process Processes.vendor_product Processes.user_id
14   Processes.process_hash Processes.parent_process_name
15   Processes.parent_process_exec Processes.action Processes.dest
16   Processes.process_current_directory Processes.process_path
17   Processes.process_integrity_level Processes.original_file_name
18   Processes.parent_process Processes.parent_process_path
19   Processes.parent_process_guid Processes.parent_process_id
20   Processes.process_guid Processes.process_id
21   Processes.user Processes.process_name
22
23
24| `drop_dm_object_name(Processes)`
25
26| `security_content_ctime(firstTime)`
27
28| `security_content_ctime(lastTime)`
29
30| `windows_azure_storage_utility_execution_via_cli_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'XmlWinEventLog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'XmlWinEventLog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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

Legitimate IT operations and cloud administrators frequently use Windows Azure Storage Tools for data management and backups. Investigate unexpected usage to rule out unauthorized access or exfiltration.

Associated Analytic Story

• Data Exfiltration

Risk Based Analytics (RBA)

Risk Message:

Azure storage utility $process_name$ executed by $parent_process_name$ on $dest$ via commandline $process$.

References

• https://blog.talosintelligence.com/emerging-interlock-ransomware/

Detection Testing

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