splunk-security_content/docs/_posts/2021-06-01-detect_azurehound_file_modifications.md

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title	excerpt	categories	last_modified_at	toc	toc_label	tags
Detect AzureHound File Modifications	Domain Account, Local Groups, Domain Trust Discovery, Local Account, Account Discovery, Domain Groups, Permission Groups Discovery	Endpoint	2021-06-01	true		Domain Account Discovery Local Groups Discovery Domain Trust Discovery Discovery Local Account Discovery Account Discovery Discovery Domain Groups Discovery Permission Groups Discovery Discovery Splunk Enterprise Splunk Enterprise Security Splunk Cloud Endpoint

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Description

The following analytic is similar to SharpHound file modifications, but this instance covers the use of Invoke-AzureHound. AzureHound is the SharpHound equivilent but for Azure. It's possible this may never be seen in an environment as most attackers may execute this tool remotely. Once execution is complete, a zip file with a similar name will drop 20210601090751-azurecollection.zip. In addition to the zip, multiple .json files will be written to disk, which are in the zip.

• Type: TTP
• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
• Datamodel: Endpoint
• Last Updated: 2021-06-01
• Author: Michael Haag, Splunk
• ID: 1c34549e-c31b-11eb-996b-acde48001122

ATT&CK

ID	Technique	Tactic
T1087.002	Domain Account	Discovery

| T1069.001 | Local Groups | Discovery |

| T1482 | Domain Trust Discovery | Discovery |

| T1087.001 | Local Account | Discovery |

| T1087 | Account Discovery | Discovery |

| T1069.002 | Domain Groups | Discovery |

| T1069 | Permission Groups Discovery | Discovery |

Search

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("*-azurecollection.zip", "*-azprivroleadminrights.json", "*-azglobaladminrights.json", "*-azcloudappadmins.json", "*-azapplicationadmins.json") by Filesystem.file_create_time Filesystem.process_id  Filesystem.file_name Filesystem.file_path Filesystem.dest 
| `drop_dm_object_name(Filesystem)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `detect_azurehound_file_modifications_filter`

Associated Analytic Story

• Discovery Techniques

How To Implement

To successfully implement this search you need to be ingesting information on file modifications that include the name of the process, and file, responsible for the changes from your endpoints into the Endpoint datamodel in the Filesystem node.

Required field

• _time
• file_path
• dest
• file_name
• process_id
• file_create_time

Kill Chain Phase

• Reconnaissance

Known False Positives

False positives should be limited as the analytic is specific to a filename with extension .zip. Filter as needed.

RBA

Risk Score	Impact	Confidence	Message
63.0	70	90	A file - file_name was written to disk that is related to AzureHound, a AzureAD enumeration utility, has occurred on endpoint dest by user user.

Reference

• https://posts.specterops.io/introducing-bloodhound-4-0-the-azure-update-9b2b26c5e350
• https://raw.githubusercontent.com/BloodHoundAD/BloodHound/master/Collectors/AzureHound.ps1

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/attack_techniques/T1059.001/sharphound/windows-sysmon.log

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