Ruben Groenewoud
79 lines
2.5 KiB
TOML
79 lines
2.5 KiB
TOML
[metadata]
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creation_date = "2025/04/30"
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integration = ["endpoint"]
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maturity = "production"
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updated_date = "2025/04/30"
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[rule]
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author = ["Elastic"]
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description = """
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This rule detects the creation of a symbolic link from a system binary to a suspicious and writable location. This
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activity may indicate an attacker's attempt to evade detection by behavioral rules that depend on predefined process
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parent/child relationships. By executing the symlinked variant of a binary instead of the original, the attacker aims to
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bypass these rules. Through the new_terms rule type, this rule can identify uncommon parent processes that may indicate the
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presence of a malicious symlink.
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"""
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from = "now-9m"
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index = [
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"logs-endpoint.events.process*",
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]
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language = "kuery"
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license = "Elastic License v2"
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name = "System Binary Symlink to Suspicious Location"
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risk_score = 21
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rule_id = "d19a2399-f8e2-4b10-80d8-a561ce9d24d1"
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severity = "low"
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tags = [
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"Domain: Endpoint",
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"OS: Linux",
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"Use Case: Threat Detection",
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"Tactic: Defense Evasion",
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"Data Source: Elastic Defend",
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]
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timestamp_override = "event.ingested"
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type = "new_terms"
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query = '''
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host.os.type:linux and event.category:process and event.type:start and event.action:exec and process.parent.executable:* and
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(process.name:ln or process.name:busybox and process.args:ln or process.name:cp and process.args:--symbolic-link) and
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process.args:(
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(
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/bin/* or /lib/* or /lib64/* or /sbin/* or /usr/bin/* or /usr/lib/* or /usr/lib64/* or /usr/local/bin/* or
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/usr/local/lib/* or /usr/local/lib64/* or /usr/local/sbin/* or /usr/sbin/*
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) and (
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/*/.* or /dev/shm/* or /home/* or /root/* or /tmp/* or /var/tmp/*
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) and
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not (/usr/bin/coreutils or /tmp/mkinitcpio* or /var/tmp/dracut* or /var/tmp/mkinitramfs*)
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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.tactic]
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name = "Defense Evasion"
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id = "TA0005"
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reference = "https://attack.mitre.org/tactics/TA0005/"
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[[rule.threat.technique]]
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name = "Hijack Execution Flow"
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id = "T1574"
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reference = "https://attack.mitre.org/techniques/T1574/"
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[[rule.threat.technique]]
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name = "Indirect Command Execution"
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id = "T1202"
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reference = "https://attack.mitre.org/techniques/T1202/"
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[[rule.threat.technique]]
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name = "Hide Artifacts"
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id = "T1564"
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reference = "https://attack.mitre.org/techniques/T1564/"
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[rule.new_terms]
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field = "new_terms_fields"
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value = ["host.id", "process.parent.name"]
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[[rule.new_terms.history_window_start]]
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field = "history_window_start"
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value = "now-10d"
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