TotalKnob
b043695833
Co-authored-by: Samirbous <64742097+Samirbous@users.noreply.github.com> Co-authored-by: Terrance DeJesus <99630311+terrancedejesus@users.noreply.github.com> Co-authored-by: Jonhnathan <jonhnathancesar@gmail.com>
98 lines
4.1 KiB
TOML
98 lines
4.1 KiB
TOML
[metadata]
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creation_date = "2020/03/16"
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maturity = "production"
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updated_date = "2022/07/29"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies use of bcdedit.exe to delete boot configuration data. This tactic is sometimes used as by malware or an
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attacker as a destructive technique.
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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 = "Modification of Boot Configuration"
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note = """## Triage and analysis
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### Investigating Modification of Boot Configuration
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Boot entry parameters, or boot parameters, are optional, system-specific settings that represent configuration options.
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These are stored in a boot configuration data (BCD) store, and administrators can use utilities like `bcdedit.exe` to
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configure these.
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This rule identifies the usage of `bcdedit.exe` to:
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- Disable Windows Error Recovery (recoveryenabled).
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- Ignore errors if there is a failed boot, failed shutdown, or failed checkpoint (bootstatuspolicy ignoreallfailures).
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These are common steps in destructive attacks by adversaries leveraging ransomware.
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#### Possible investigation steps
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- Investigate the script execution chain (parent process tree) for unknown processes. Examine their executable files for
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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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- Contact the account owner and confirm whether they are aware of this activity.
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- Investigate other alerts associated with the user/host during the past 48 hours.
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- Assess whether this behavior is prevalent in the environment by looking for similar occurrences across hosts.
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- Check if any files on the host machine have been encrypted.
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### False positive analysis
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- The usage of these options is not inherently malicious. Administrators can modify these configurations to force a
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machine to boot for troubleshooting or data recovery purposes.
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### Related rules
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- Deleting Backup Catalogs with Wbadmin - 581add16-df76-42bb-af8e-c979bfb39a59
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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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- Consider isolating the involved host to prevent destructive behavior, which is commonly associated with this activity.
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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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- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look
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for ransomware preparation and execution activities.
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- Determine the initial vector abused by the attacker and take action to prevent reinfection through 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 = 21
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rule_id = "69c251fb-a5d6-4035-b5ec-40438bd829ff"
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severity = "low"
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tags = ["Elastic", "Host", "Windows", "Threat Detection", "Impact"]
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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 : "bcdedit.exe" or process.pe.original_file_name == "bcdedit.exe") and
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(
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(process.args : "/set" and process.args : "bootstatuspolicy" and process.args : "ignoreallfailures") or
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(process.args : "no" and process.args : "recoveryenabled")
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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 = "T1490"
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name = "Inhibit System Recovery"
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reference = "https://attack.mitre.org/techniques/T1490/"
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[rule.threat.tactic]
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id = "TA0040"
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name = "Impact"
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reference = "https://attack.mitre.org/tactics/TA0040/"
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