Justin Ibarra
6bdfddac8e
* Expand timestamp_override tests * removed timestamp_override from eql sequence rules * add config entry for eql rules with beats index and t_o * add timestamp_override to missing fields
88 lines
3.1 KiB
TOML
88 lines
3.1 KiB
TOML
[metadata]
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creation_date = "2021/11/25"
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maturity = "production"
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updated_date = "2022/03/31"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies a potential exploitation of InstallerTakeOver (CVE-2021-41379) default PoC execution. Successful exploitation
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allows an unprivileged user to escalate privileges to SYSTEM.
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"""
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from = "now-9m"
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index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Potential Privilege Escalation via InstallerFileTakeOver"
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note = """## Triage and analysis.
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### Investigating Potential Priivilege Escalation via InstallerFileTakeOver
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InstallerFileTakeOver is a weaponized EoP PoC to the CVE-2021-41379 vulnerability. Upon successful exploitation,
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an unprivileged user will escalate privileges to SYSTEM/NT AUTHORITY.
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This rule detects the default execution of the PoC, which overwrites the `elevation_service.exe` DACL and copies itself
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to the location to escalate privileges. An attacker is able to still take over any file that is not in use (locked), which is outside the scope of this rule.
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#### Possible investigation steps:
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- Check for the digital signature of the executable.
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- Look for additional processes spawned by the process, command lines, and network communications.
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- Look for additional alerts involving the host and the user.
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### False Positive Analysis
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- Verify whether the digital signature exists in the executable, and if it is valid.
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### Related Rules
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- Suspicious DLL Loaded for Persistence or Privilege Escalation - bfeaf89b-a2a7-48a3-817f-e41829dc61ee
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### Response and Remediation
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- Immediate response steps should be taken to validate, investigate, and potentially contain the activity to prevent
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further post-compromise behavior.
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## Config
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If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
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"""
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references = ["https://github.com/klinix5/InstallerFileTakeOver"]
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risk_score = 73
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rule_id = "58c6d58b-a0d3-412d-b3b8-0981a9400607"
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severity = "high"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Privilege Escalation"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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/* This rule is compatible with both Sysmon and Elastic Endpoint */
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process where event.type == "start" and
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(process.Ext.token.integrity_level_name : "System" or
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winlog.event_data.IntegrityLevel : "System") and
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(
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(process.name : "elevation_service.exe" and
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not process.pe.original_file_name == "elevation_service.exe") or
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(process.parent.name : "elevation_service.exe" and
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process.name : ("rundll32.exe", "cmd.exe", "powershell.exe"))
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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 = "T1068"
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name = "Exploitation for Privilege Escalation"
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reference = "https://attack.mitre.org/techniques/T1068/"
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[rule.threat.tactic]
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id = "TA0004"
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name = "Privilege Escalation"
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reference = "https://attack.mitre.org/tactics/TA0004/"
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