shashank-elastic
3ed8c56942
Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
61 lines
2.2 KiB
TOML
61 lines
2.2 KiB
TOML
[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 = "2023/06/15"
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[rule]
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author = ["Elastic"]
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description = """
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This rule identifies a 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. Ransomware is a type of
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malware that encrypts a victim's files or systems and demands payment (usually in cryptocurrency) in exchange for the
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decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a
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new file extension is added to the file.
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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 = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: 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 != "" and
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file.path : (
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"/home/*", "/etc/*", "/root/*", "/opt/*", "/var/backups/*", "/var/lib/log/*"
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) and not
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file.extension : (
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"xml", "json", "conf", "dat", "gz", "info", "mod", "final",
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"php", "pyc", "log", "bak", "bin", "csv", "pdf", "cfg", "*old"
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) and not
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process.name : (
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"dpkg", "yum", "dnf", "rpm", "dockerd"
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) ] with runs=100
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[ file where host.os.type == "linux" and event.action == "creation" and file.extension == "txt" and
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file.name : (
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"*crypt*", "*restore*", "*lock*", "*recovery*", "*data*",
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"*read*", "*instruction*", "*how_to*", "*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/" |