Samirbous
b15f0de9a4
* [Rules Tuning] 7 diverse Windows rules Excluding FP patterns while avoiding breaking compat with winlogbeat and 4688 events lack of codesign metadata. * Update initial_access_suspicious_ms_exchange_process.toml * Update privilege_escalation_persistence_phantom_dll.toml * Update execution_psexec_lateral_movement_command.toml * Update persistence_remote_password_reset.toml * Update non-ecs-schema.json * Update persistence_remote_password_reset.toml * Update non-ecs-schema.json * Update discovery_privileged_localgroup_membership.toml
63 lines
2.3 KiB
TOML
63 lines
2.3 KiB
TOML
[metadata]
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creation_date = "2021/03/04"
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maturity = "production"
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updated_date = "2022/08/02"
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[rule]
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author = ["Elastic", "Austin Songer"]
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description = """
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Identifies suspicious processes being spawned by the Microsoft Exchange Server Unified Messaging (UM) service. This
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activity has been observed exploiting CVE-2021-26857.
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"""
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false_positives = [
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"""
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Legitimate processes may be spawned from the Microsoft Exchange Server Unified Messaging (UM) service. If known
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processes are causing false positives, they can be exempted from the rule.
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""",
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]
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from = "now-9m"
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index = ["logs-endpoint.events.*", "winlogbeat-*", "logs-windows.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Microsoft Exchange Server UM Spawning Suspicious Processes"
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note = """## Setup
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If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
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"""
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references = [
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"https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers",
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"https://www.volexity.com/blog/2021/03/02/active-exploitation-of-microsoft-exchange-zero-day-vulnerabilities",
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]
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risk_score = 47
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rule_id = "483c4daf-b0c6-49e0-adf3-0bfa93231d6b"
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severity = "medium"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Initial Access"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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process where event.type == "start" and
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process.parent.name : ("UMService.exe", "UMWorkerProcess.exe") and
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not process.executable :
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("?:\\Windows\\System32\\werfault.exe",
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"?:\\Windows\\System32\\wermgr.exe",
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"?:\\Program Files\\Microsoft\\Exchange Server\\V??\\Bin\\UMWorkerProcess.exe",
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"D:\\Exchange 2016\\Bin\\UMWorkerProcess.exe",
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"E:\\ExchangeServer\\Bin\\UMWorkerProcess.exe")
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1190"
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name = "Exploit Public-Facing Application"
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reference = "https://attack.mitre.org/techniques/T1190/"
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[rule.threat.tactic]
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id = "TA0001"
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name = "Initial Access"
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reference = "https://attack.mitre.org/tactics/TA0001/"
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