Justin Ibarra
62 lines
2.6 KiB
TOML
62 lines
2.6 KiB
TOML
[metadata]
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creation_date = "2020/07/16"
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maturity = "production"
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updated_date = "2021/05/10"
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[rule]
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author = ["Elastic"]
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description = """
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Specially crafted DNS requests can manipulate a known overflow vulnerability in some Windows DNS servers which result in
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Remote Code Execution (RCE) or a Denial of Service (DoS) from crashing the service.
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"""
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false_positives = [
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"""
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Environments that leverage DNS responses over 60k bytes will result in false positives - if this traffic is
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predictable and expected, it should be filtered out. Additionally, this detection rule could be triggered by an
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authorized vulnerability scan or compromise assessment.
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""",
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]
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index = ["packetbeat-*", "filebeat-*"]
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language = "kuery"
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license = "Elastic License v2"
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name = "Abnormally Large DNS Response"
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note = """## Triage and analysis
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### Investigating Large DNS Responses
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Detection alerts from this rule indicate an attempt was made to exploit CVE-2020-1350 (SigRed) through the use of large DNS responses on a Windows DNS server. Here are some possible avenues of investigation:
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- Investigate any corresponding Intrusion Detection Signatures (IDS) alerts that can validate this detection alert.
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- Examine the `dns.question_type` network fieldset with a protocol analyzer, such as Zeek, Packetbeat, or Suricata, for `SIG` or `RRSIG` data.
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- Validate the patch level and OS of the targeted DNS server to validate the observed activity was not large-scale Internet vulnerability scanning.
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- Validate that the source of the network activity was not from an authorized vulnerability scan or compromise assessment."""
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references = [
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"https://research.checkpoint.com/2020/resolving-your-way-into-domain-admin-exploiting-a-17-year-old-bug-in-windows-dns-servers/",
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"https://msrc-blog.microsoft.com/2020/07/14/july-2020-security-update-cve-2020-1350-vulnerability-in-windows-domain-name-system-dns-server/",
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"https://github.com/maxpl0it/CVE-2020-1350-DoS",
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]
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risk_score = 47
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rule_id = "11013227-0301-4a8c-b150-4db924484475"
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severity = "medium"
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tags = ["Elastic", "Network", "Threat Detection", "Lateral Movement"]
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timestamp_override = "event.ingested"
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type = "query"
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query = '''
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event.category:(network or network_traffic) and destination.port:53 and
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(event.dataset:zeek.dns or type:dns or event.type:connection) and network.bytes > 60000
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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 = "T1210"
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name = "Exploitation of Remote Services"
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reference = "https://attack.mitre.org/techniques/T1210/"
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[rule.threat.tactic]
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id = "TA0008"
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name = "Lateral Movement"
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reference = "https://attack.mitre.org/tactics/TA0008/"
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