60 lines
2.0 KiB
TOML
60 lines
2.0 KiB
TOML
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[metadata]
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creation_date = "2023/03/20"
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integration = ["endpoint"]
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maturity = "production"
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min_stack_comments = "New fields added: required_fields, related_integrations, setup"
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min_stack_version = "8.3.0"
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updated_date = "2023/03/20"
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[rule]
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author = ["Elastic"]
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description = """
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Ransomware is a type of malware that encrypts a victim's files or systems and demands payment
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(usually in cryptocurrency) in exchange for the decryption key. One important indicator of a
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ransomware attack is the mass encryption of the file system, after which a new file extension
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is added to the file. Generally, a ransomware note with contact details is dropped onto the
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file system which can be used by the victim to contact the attacker. This rule identifies a
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sequence of a mass file encryption event in conjunction with the creation of a .txt file with
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a file name containing ransomware keywords executed by the same process in a 1 second timespan.
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"""
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from = "now-9m"
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index = ["logs-endpoint.events.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Potential Linux Ransomware Note Creation Detected"
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risk_score = 73
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rule_id = "c8935a8b-634a-4449-98f7-bb24d3b2c0af"
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severity = "high"
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tags = ["Elastic", "Host", "Linux", "Threat Detection", "Impact"]
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type = "eql"
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query = '''
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sequence by host.id, process.entity_id with maxspan=1s
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[ file where host.os.type == "linux" and event.type == "change" and
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event.action == "rename" and file.extension != "" ] with runs=50
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[ file where host.os.type == "linux" and event.action == "creation" and
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file.extension == "txt" and file.name : (
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"*crypt*",
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"*restore*",
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"*lock*",
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"*recovery*",
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"*data*",
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"*read*",
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"*instruction*",
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"*how_to*",
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"*ransom*"
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) ] | tail 1
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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 = "T1486"
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name = "Data Encrypted for Impact"
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reference = "https://attack.mitre.org/techniques/T1486/"
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[rule.threat.tactic]
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id = "TA0040"
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name = "Impact"
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reference = "https://attack.mitre.org/tactics/TA0040/"
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