Justin Ibarra
645a0cd67b
* [Rule Tuning] Add timestamp_override field to rules * add tests for lookback and timestamp_override * fix dates and add test to ensure updated > creation
88 lines
2.5 KiB
TOML
88 lines
2.5 KiB
TOML
[metadata]
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creation_date = "2020/12/21"
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maturity = "production"
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updated_date = "2021/02/11"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies a Secure Shell (SSH) client or server process creating or writing to a known SSH backdoor log file.
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Adversaries may modify SSH related binaries for persistence or credential access via patching sensitive functions to
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enable unauthorized access or to log SSH credentials for exfiltration.
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"""
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false_positives = ["Updates to approved and trusted SSH executables can trigger this rule."]
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from = "now-9m"
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index = ["auditbeat-*", "logs-endpoint.events.*"]
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language = "eql"
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license = "Elastic License"
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name = "Potential OpenSSH Backdoor Logging Activity"
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references = [
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"https://github.com/eset/malware-ioc/tree/master/sshdoor",
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"https://www.welivesecurity.com/wp-content/uploads/2021/01/ESET_Kobalos.pdf",
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]
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risk_score = 73
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rule_id = "f28e2be4-6eca-4349-bdd9-381573730c22"
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severity = "high"
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tags = ["Elastic", "Host", "Linux", "Threat Detection", "Persistence", "Credential Access"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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file where event.type == "change" and process.executable : ("/usr/sbin/sshd", "/usr/bin/ssh") and
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(
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file.name : (".*", "~*") or
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file.extension : ("in", "out", "ini", "h", "gz", "so", "sock", "sync", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9") or
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file.path :
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(
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"/private/etc/*--",
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"/usr/share/*",
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"/usr/include/*",
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"/usr/local/include/*",
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"/private/tmp/*",
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"/private/var/tmp/*",
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"/usr/tmp/*",
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"/usr/share/man/*",
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"/usr/local/share/*",
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"/usr/lib/*.so.*",
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"/private/etc/ssh/.sshd_auth",
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"/usr/bin/ssd",
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"/private/var/opt/power",
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"/private/etc/ssh/ssh_known_hosts",
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"/private/var/html/lol",
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"/private/var/log/utmp",
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"/private/var/lib",
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"/var/run/sshd/sshd.pid",
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"/var/run/nscd/ns.pid",
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"/var/run/udev/ud.pid",
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"/var/run/udevd.pid"
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)
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)
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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 = "T1556"
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name = "Modify Authentication Process"
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reference = "https://attack.mitre.org/techniques/T1556/"
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[rule.threat.tactic]
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id = "TA0006"
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name = "Credential Access"
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reference = "https://attack.mitre.org/tactics/TA0006/"
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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 = "T1554"
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name = "Compromise Client Software Binary"
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reference = "https://attack.mitre.org/techniques/T1554/"
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[rule.threat.tactic]
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id = "TA0003"
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name = "Persistence"
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reference = "https://attack.mitre.org/tactics/TA0003/"
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