[metadata] creation_date = "2021/07/15" integration = ["o365"] maturity = "production" min_stack_comments = "New fields added: required_fields, related_integrations, setup" min_stack_version = "8.3.0" updated_date = "2023/06/22" [rule] author = ["Austin Songer"] description = """ Identifies when Microsoft Cloud App Security reports that a user has uploaded files to the cloud that might be infected with ransomware. """ false_positives = [ """ If Cloud App Security identifies, for example, a high rate of file uploads or file deletion activities it may represent an adverse encryption process. """, ] from = "now-30m" index = ["filebeat-*", "logs-o365*"] language = "kuery" license = "Elastic License v2" name = "Microsoft 365 Potential ransomware activity" note = """## Setup The Office 365 Logs Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule. """ references = [ "https://docs.microsoft.com/en-us/cloud-app-security/anomaly-detection-policy", "https://docs.microsoft.com/en-us/cloud-app-security/policy-template-reference", ] risk_score = 47 rule_id = "721999d0-7ab2-44bf-b328-6e63367b9b29" severity = "medium" tags = ["Domain: Cloud", "Data Source: Microsoft 365", "Use Case: Configuration Audit", "Tactic: Impact"] timestamp_override = "event.ingested" type = "query" query = ''' event.dataset:o365.audit and event.provider:SecurityComplianceCenter and event.category:web and event.action:"Potential ransomware activity" and event.outcome:success ''' [[rule.threat]] framework = "MITRE ATT&CK" [[rule.threat.technique]] id = "T1486" name = "Data Encrypted for Impact" reference = "https://attack.mitre.org/techniques/T1486/" [rule.threat.tactic] id = "TA0040" name = "Impact" reference = "https://attack.mitre.org/tactics/TA0040/"