Mika Ayenson
a52751494e
* Convert config header to setup in note field * Parse note field into separate setup and note field with marko gfm * only validate and parse note on elastic authored rules and add CLI description for new DR_BYPASS_NOTE_VALIDATION_AND_PARSE environment variable Co-authored-by: brokensound77 <brokensound77@users.noreply.github.com>
100 lines
4.3 KiB
TOML
100 lines
4.3 KiB
TOML
[metadata]
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creation_date = "2020/12/04"
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maturity = "production"
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updated_date = "2022/04/21"
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[rule]
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author = ["Elastic"]
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description = "Identifies attempts to enumerate hosts in a network using the built-in Windows net.exe tool."
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from = "now-9m"
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index = ["logs-endpoint.events.*", "winlogbeat-*", "logs-windows.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Windows Network Enumeration"
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note = """## Triage and analysis
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### Investigating Windows Network Enumeration
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After successfully compromising an environment, attackers may try to gain situational awareness to plan their next steps.
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This can happen by running commands to enumerate network resources, users, connections, files, and installed security
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software.
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This rule looks for the execution of the `net` utility to enumerate servers in the environment that hosts shared drives
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or printers. This information is useful to attackers as they can identify targets for lateral movements and search for
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valuable shared data.
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#### Possible investigation steps
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- Investigate the process execution chain (parent process tree) for unknown processes. Examine their executable files
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for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.
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- Identify the user account that performed the action and whether it should perform this kind of action.
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- Investigate other alerts associated with the user/host during the past 48 hours.
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- Investigate abnormal behaviors observed using the account, such as commands executed, files created or modified, and
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network connections.
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### False positive analysis
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- Discovery activities are not inherently malicious if they occur in isolation. As long as the analyst did not identify
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suspicious activity related to the user or host, such alerts can be dismissed.
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### Response and remediation
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- Initiate the incident response process based on the outcome of the triage.
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- Isolate the involved hosts to prevent further post-compromise behavior.
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- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are
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identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business
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systems, and web services.
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- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and
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malware components.
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- Determine the initial vector abused by the attacker and take action to prevent reinfection via the same vector.
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- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the
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mean time to respond (MTTR).
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## Setup
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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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risk_score = 47
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rule_id = "7b8bfc26-81d2-435e-965c-d722ee397ef1"
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severity = "medium"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Discovery"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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process where event.type in ("start", "process_started") and
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((process.name : "net.exe" or process.pe.original_file_name == "net.exe") or
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((process.name : "net1.exe" or process.pe.original_file_name == "net1.exe") and
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not process.parent.name : "net.exe")) and
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(process.args : "view" or (process.args : "time" and process.args : "\\\\*"))
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/* expand when ancestry is available
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and not descendant of [process where event.type == ("start", "process_started") and process.name : "cmd.exe" and
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((process.parent.name : "userinit.exe") or
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(process.parent.name : "gpscript.exe") or
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(process.parent.name : "explorer.exe" and
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process.args : "C:\\*\\Start Menu\\Programs\\Startup\\*.bat*"))]
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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 = "T1018"
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name = "Remote System Discovery"
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reference = "https://attack.mitre.org/techniques/T1018/"
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[[rule.threat.technique]]
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id = "T1135"
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name = "Network Share Discovery"
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reference = "https://attack.mitre.org/techniques/T1135/"
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[rule.threat.tactic]
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id = "TA0007"
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name = "Discovery"
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reference = "https://attack.mitre.org/tactics/TA0007/"
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