Terrance DeJesus
96 lines
4.0 KiB
TOML
96 lines
4.0 KiB
TOML
[metadata]
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creation_date = "2020/12/04"
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deprecation_date = "2022/08/02"
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maturity = "deprecated"
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updated_date = "2022/08/02"
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[rule]
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author = ["Elastic"]
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description = """
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Enumeration of files and directories using built-in tools. Adversaries may use the information discovered to plan
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follow-on activity.
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"""
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false_positives = [
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"""
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Enumeration of files and directories may not be inherently malicious and noise may come from scripts, automation
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tools, or normal command line usage. It's important to baseline your environment to determine the amount of expected
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noise and exclude any known FP's from the rule.
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""",
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]
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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 = "File and Directory Discovery"
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note = """## Triage and analysis
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### Investigating File and Directory Discovery
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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 three directory-listing commands in one minute, which can indicate attempts to locate valuable files,
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specific file types or installed programs.
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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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"""
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risk_score = 21
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rule_id = "7b08314d-47a0-4b71-ae4e-16544176924f"
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severity = "low"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Discovery"]
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type = "eql"
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query = '''
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sequence by agent.id, user.name with maxspan=1m
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[process where event.type in ("start", "process_started") and
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((process.name : "cmd.exe" or process.pe.original_file_name == "Cmd.Exe") and process.args : "dir") or
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process.name : "tree.com"]
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[process where event.type in ("start", "process_started") and
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((process.name : "cmd.exe" or process.pe.original_file_name == "Cmd.Exe") and process.args : "dir") or
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process.name : "tree.com"]
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[process where event.type in ("start", "process_started") and
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((process.name : "cmd.exe" or process.pe.original_file_name == "Cmd.Exe") and process.args : "dir") or
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process.name : "tree.com"]
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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 = "T1083"
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name = "File and Directory Discovery"
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reference = "https://attack.mitre.org/techniques/T1083/"
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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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