Detect SharpHound File Modifications

Name:Detect SharpHound File Modifications
id:42b4b438-beed-11eb-ba1d-acde48001122
version:13
date:None
author:Michael Haag, Splunk
status:production
type:TTP
Description:The following analytic detects the creation of files typically associated with SharpHound, a reconnaissance tool used for gathering domain and trust data. It leverages file modification events from the Endpoint.Filesystem data model, focusing on default file naming patterns like `*_BloodHound.zip` and various JSON files. This activity is significant as it indicates potential domain enumeration, which is a precursor to more targeted attacks. If confirmed malicious, an attacker could gain detailed insights into the domain structure, facilitating lateral movement and privilege escalation.
Data_source:

• -Sysmon EventID 11

search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem
WHERE Filesystem.file_name IN ("*bloodhound.zip", "*_computers.json", "*_gpos.json", "*_domains.json", "*_users.json", "*_groups.json", "*_ous.json", "*_containers.json")
BY Filesystem.action Filesystem.dest Filesystem.file_access_time
Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time
Filesystem.file_name Filesystem.file_path Filesystem.file_acl
Filesystem.file_size Filesystem.process_guid Filesystem.process_id
Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `detect_sharphound_file_modifications_filter`

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.
known_false_positives:False positives should be limited as the analytic is specific to a filename with extension .zip. Filter as needed.
References:
  -https://attack.mitre.org/software/S0521/
  -https://thedfirreport.com/?s=bloodhound
  -https://github.com/BloodHoundAD/BloodHound/tree/master/Collectors
  -https://github.com/BloodHoundAD/SharpHound3
  -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1059.001/T1059.001.md#atomic-test-2---run-bloodhound-from-local-disk
  -https://github.com/redcanaryco/atomic-red-team/blob/388942adbd9641f4dfdcf079d7efe9a75ec0ac43/atomics/T1059.001/T1059.001.yaml#L36
drilldown_searches:
 name:'View the detection results for - "$dest$" and "$user$"'
 search:'%original_detection_search% | search dest = "$dest$" user = "$user$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$dest$" and "$user$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
 earliest_offset:'7d'
 latest_offset:'0'
analytic_story:['Windows Discovery Techniques', 'Ransomware', 'BlackSuit Ransomware']

asset_type:Endpoint

mitre_attack_id:['T1069.001', 'T1069.002', 'T1087.001', 'T1087.002', 'T1482']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:endpoint

security_domain:endpoint

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/sharphound/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None