[New Rule] SharePoint Malware File Upload (#1691)

* "SharePoint Malware File Upload" Initial Rule

* s/onedrive/sharepoint

* bump severity

rules/integrations/o365/lateral_movement_malware_uploaded_sharepoint.toml

@@ -0,0 +1,51 @@
+[metadata]
+creation_date = "2022/01/10"
+integration = "o365"
+maturity = "production"
+updated_date = "2022/01/10"
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies the occurence of files uploaded to SharePoint being detected as Malware by the file scanning engine. Attackers
+can use File Sharing and Organization Repositories to spread laterally within the company and amplify their access.
+Users can inadvertently share these files without knowing their maliciousness, giving adversaries opportunity to gain
+initial access to other endpoints in the environment.
+"""
+false_positives = ["Benign files can trigger signatures in the built-in virus protection"]
+from = "now-30m"
+index = ["filebeat-*", "logs-o365*"]
+language = "kuery"
+license = "Elastic License v2"
+name = "SharePoint Malware File Upload"
+note = """## Config
+
+The Microsoft 365 Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule."""
+references = [
+    "https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/virus-detection-in-spo?view=o365-worldwide",
+]
+risk_score = 73
+rule_id = "0e52157a-8e96-4a95-a6e3-5faae5081a74"
+severity = "high"
+tags = ["Elastic", "Cloud", "Microsoft 365", "Continuous Monitoring", "SecOps", "Lateral Movement"]
+timestamp_override = "event.ingested"
+type = "query"
+
+query = '''
+event.dataset:o365.audit and event.provider:SharePoint and event.code:SharePointFileOperation and event.action:FileMalwareDetected
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+reference = "https://attack.mitre.org/techniques/T1080/"
+id = "T1080"
+name = "Taint Shared Content"
+
+
+[rule.threat.tactic]
+reference = "https://attack.mitre.org/tactics/TA0008/"
+id = "TA0008"
+name = "Lateral Movement"