Name:Windows Raw Access To Disk Volume Partition id:a85aa37e-9647-11ec-90c5-acde48001122 version:3 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects suspicious raw access reads to the device disk partition of a host machine. It leverages Sysmon EventCode 9 logs to identify processes attempting to read or write to the boot sector, excluding legitimate system processes. This activity is significant as it is commonly associated with destructive actions by adversaries, such as wiping, encrypting, or overwriting the boot sector, as seen in attacks involving malware like HermeticWiper. If confirmed malicious, this behavior could lead to severe impacts, including system inoperability, data loss, or compromised boot integrity. Data_source:
-Sysmon EventID 9
search:`sysmon` EventCode=9 Device = \\Device\\HarddiskVolume* NOT (Image IN("*\\Windows\\System32\\*", "*\\Windows\\SysWOW64\\*")) | stats count min(_time) as firstTime max(_time) as lastTime by dest signature signature_id process_guid process_name process_path Device | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_raw_access_to_disk_volume_partition_filter`
how_to_implement:To successfully implement this search, you need to be ingesting logs with the raw access read event (like sysmon eventcode 9), process name and process guid from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. known_false_positives:This event is really notable but we found minimal number of normal application from system32 folder like svchost.exe accessing it too. In this case we used 'system32' and 'syswow64' path as a filter for this detection. References: -https://blog.talosintelligence.com/2022/02/threat-advisory-hermeticwiper.html drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | 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:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'CISA AA22-264A' - 'Graceful Wipe Out Attack' - 'Data Destruction' - 'Hermetic Wiper' - 'Caddy Wiper' - 'BlackByte Ransomware' - 'NjRAT' asset_type:Endpoint confidence:100 impact:90 message:Process accessing disk partition $Device$ in $dest$ mitre_attack_id: - 'T1561.002' - 'T1561' observable: name:'dest' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'dest' - 'signature' - 'signature_id' - 'process_guid' - 'process_name' - 'process_path' - 'Device' - 'EventCode' - 'Image' risk_score:90 security_domain:endpoint
