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Description

The following analytic identifies the usage of mshta.exe Windows binary in registry to execute malicious script. This technique was seen in kovter malware where it create several registry entry which is a encoded javascript and will be executed by another registry containing mshta and javascript activexobject to execute the encoded script using wscript.shell. This TTP is a good indication of kovter malware or other adversaries or threat actors leveraging fileless detection that survive system reboot.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-10-14
  • Author: Teoderick Contreras, Splunk
  • ID: e13ceade-b673-4d34-adc4-4d9c01729753

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1218.005 Mshta Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 3
  • CIS 5
  • CIS 16
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry where Registry.registry_value_data = "*mshta*" OR Registry.registry_value_data IN ("*javascript:*", "*vbscript:*","*WScript.Shell*") by Registry.registry_key_name Registry.registry_path Registry.registry_value_data Registry.action Registry.dest 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_mshta_execution_in_registry_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_mshta_execution_in_registry_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
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.dest
  • Registry.registry_value_data
  • Registry.action

How To Implement

To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.

Known False Positives

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
72.0 80 90 a registry $registry_path$ contains mshta $registry_value_data$ in $dest$

: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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