:warning: THIS IS A EXPERIMENTAL DETECTION

This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.

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Description

The following analytic identifies the process name of java.exe and w3wp.exe spawning a Windows shell. This is potentially indicative of exploitation of the Java application and may be related to current event CVE-2021-44228 (Log4Shell). The shells included in the macro are "cmd.exe", "powershell.exe". Upon triage, review parallel processes and command-line arguments to determine legitimacy.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-01-23
  • Author: Michael Haag, Splunk
  • ID: 28c81306-5c47-11ec-bfea-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
T1133 External Remote Services Persistence, Initial Access
Kill Chain Phase
  • Delivery
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE
ID Summary CVSS
CVE-2021-44228 Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects. 9.3
CVE-2022-47966 Multiple Zoho ManageEngine on-premise products, such as ServiceDesk Plus through 14003, allow remote code execution due to use of Apache Santuario xmlsec (aka XML Security for Java) 1.4.1, because the xmlsec XSLT features, by design in that version, make the application responsible for certain security protections, and the ManageEngine applications did not provide those protections. This affects Access Manager Plus before 4308, Active Directory 360 before 4310, ADAudit Plus before 7081, ADManager Plus before 7162, ADSelfService Plus before 6211, Analytics Plus before 5150, Application Control Plus before 10.1.2220.18, Asset Explorer before 6983, Browser Security Plus before 11.1.2238.6, Device Control Plus before 10.1.2220.18, Endpoint Central before 10.1.2228.11, Endpoint Central MSP before 10.1.2228.11, Endpoint DLP before 10.1.2137.6, Key Manager Plus before 6401, OS Deployer before 1.1.2243.1, PAM 360 before 5713, Password Manager Pro before 12124, Patch Manager Plus before 10.1.2220.18, Remote Access Plus before 10.1.2228.11, Remote Monitoring and Management (RMM) before 10.1.41. ServiceDesk Plus before 14004, ServiceDesk Plus MSP before 13001, SupportCenter Plus before 11026, and Vulnerability Manager Plus before 10.1.2220.18. Exploitation is only possible if SAML SSO has ever been configured for a product (for some products, exploitation requires that SAML SSO is currently active). None 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name=java.exe OR Processes.parent_process_name=w3wp.exe `windows_shells` by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_java_spawning_shells_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_java_spawning_shells_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

Filtering may be required on internal developer build systems or classify assets as web facing and restrict the analytic based on that.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
40.0 80 50 An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ spawning a Windows shell, potentially indicative of exploitation.

: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

source | version: 2