From fa9da023dd5e44af8d9e45a8dc701faaf6faa3dc Mon Sep 17 00:00:00 2001 From: Austin Songer Date: Tue, 12 Oct 2021 16:30:49 -0500 Subject: [PATCH] [New Rule] Microsoft 365 - Unusual Volume of File Deletion (#1347) * Create impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update rules/microsoft-365/impact_microsoft_365_unusual_volume_of_file_deletion.toml Co-authored-by: Jonhnathan * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Update impact_microsoft_365_unusual_volume_of_file_deletion.toml * Add missing `\` * Bump to prod and update description Co-authored-by: Jonhnathan Co-authored-by: Justin Ibarra --- ...t_365_unusual_volume_of_file_deletion.toml | 47 +++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 rules/microsoft-365/impact_microsoft_365_unusual_volume_of_file_deletion.toml diff --git a/rules/microsoft-365/impact_microsoft_365_unusual_volume_of_file_deletion.toml b/rules/microsoft-365/impact_microsoft_365_unusual_volume_of_file_deletion.toml new file mode 100644 index 000000000..0e63464cd --- /dev/null +++ b/rules/microsoft-365/impact_microsoft_365_unusual_volume_of_file_deletion.toml @@ -0,0 +1,47 @@ +[metadata] +creation_date = "2021/07/15" +maturity = "production" +updated_date = "2021/07/15" +integration = "o365" + +[rule] +author = ["Austin Songer"] +description = """ +Identifies that a user has deleted an unusually large volume of files as reported by Microsoft Cloud App Security. +""" +false_positives = ["Users or System Administrator cleaning out folders."] +from = "now-30m" +index = ["filebeat-*", "logs-o365*"] +language = "kuery" +license = "Elastic License v2" +name = "Microsoft 365 Unusual Volume of File Deletion" +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/cloud-app-security/anomaly-detection-policy", + "https://docs.microsoft.com/en-us/cloud-app-security/policy-template-reference", +] +risk_score = 47 +rule_id = "b2951150-658f-4a60-832f-a00d1e6c6745" +severity = "medium" +tags = ["Elastic", "Cloud", "Microsoft 365", "Continuous Monitoring", "SecOps", "Configuration Audit"] +timestamp_override = "event.ingested" +type = "query" + +query = ''' +event.dataset:o365.audit and event.provider:SecurityComplianceCenter and event.category:web and event.action:"Unusual volume of file deletion" and event.outcome:success +''' + +[[rule.threat]] +framework = "MITRE ATT&CK" +[[rule.threat.technique]] +name = "Data Destruction" +reference = "https://attack.mitre.org/techniques/T1485/" +id = "T1485" + +[rule.threat.tactic] +name = "Impact" +reference = "https://attack.mitre.org/tactics/TA0040/" +id = "TA0040"