splunk-security_content/docs/_posts/2021-07-30-office_application_spawn_regsvr32_process.md

title, excerpt, categories, last_modified_at, toc, toc_label, tags

title	excerpt	categories	last_modified_at	toc	toc_label	tags
Office Application Spawn Regsvr32 process	Phishing, Spearphishing Attachment	Endpoint	2021-07-30	true		Phishing Initial Access Spearphishing Attachment Initial Access Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

Try in Splunk Security Cloud{: .btn .btn--success}

Description

this detection was designed to identifies suspicious spawned process of known MS office application due to macro or malicious code. this technique can be seen in so many malware like IcedID that used MS office as its weapon or attack vector to initially infect the machines.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-07-30
• Author: Teoderick Contreras, Splunk
• ID: 2d9fc90c-f11f-11eb-9300-acde48001122

ATT&CK

ID	Technique	Tactic
T1566	Phishing	Initial Access

| T1566.001 | Spearphishing Attachment | Initial Access |

Search

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.parent_process_name = "winword.exe" OR Processes.parent_process_name = "excel.exe" OR Processes.parent_process_name = "powerpnt.exe" OR Processes.parent_process_name = "outlook.exe") `process_regsvr32` by Processes.parent_process_name Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.process_guid Processes.user Processes.dest 
| `drop_dm_object_name("Processes")` 
| `security_content_ctime(firstTime)` 
|`security_content_ctime(lastTime)` 
| `office_application_spawn_regsvr32_process_filter`

Associated Analytic Story

• IcedID

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Required field

• _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

Kill Chain Phase

• Exploitation

Known False Positives

unknown

RBA

Risk Score	Impact	Confidence	Message
63.0	70	90	Office application spawning regsvr32.exe on dest

Reference

• https://www.joesandbox.com/analysis/380662/0/html

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

• https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/malware/icedid/phish_icedid/windows-sysmon.log

source | version: 2