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>
93 lines
4.1 KiB
TOML
93 lines
4.1 KiB
TOML
[metadata]
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creation_date = "2020/03/18"
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maturity = "production"
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min_stack_comments = "EQL optional fields syntax was not introduced until 7.16"
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min_stack_version = "7.16.0"
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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 = """
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Identifies when the SYSTEM account uses an account discovery utility. This could be a sign of discovery activity after
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an adversary has achieved privilege escalation.
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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 = "Account Discovery Command via SYSTEM Account"
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note = """## Triage and analysis
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### Investigating Account Discovery Command via SYSTEM Account
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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 account discovery utilities using the SYSTEM account, which is commonly observed
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after attackers successfully perform privilege escalation or exploit web applications.
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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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- If the process tree includes a web-application server process such as w3wp, httpd.exe, nginx.exe and alike,
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investigate any suspicious file creation or modification in the last 48 hours to assess the presence of any potential
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webshell backdoor.
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- Investigate other alerts associated with the user/host during the past 48 hours.
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- Determine how the SYSTEM account is being used. For example, users with administrator privileges can spawn a system
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shell using Windows services, scheduled tasks or other third party utilities.
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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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- Use the data collected through the analysis to investigate other machines affected in the environment.
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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 = 21
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rule_id = "2856446a-34e6-435b-9fb5-f8f040bfa7ed"
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severity = "low"
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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.Ext.token.integrity_level_name : "System" or
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?winlog.event_data.IntegrityLevel : "System") and
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(process.name : "whoami.exe" or
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(process.name : "net1.exe" and not process.parent.name : "net.exe"))
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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 = "T1033"
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name = "System Owner/User Discovery"
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reference = "https://attack.mitre.org/techniques/T1033/"
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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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