IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Modification of Boot Configuration
editModification of Boot Configuration
editIdentifies use of bcdedit.exe
to delete boot configuration data. This tactic is sometimes used as by malware or an attacker as a destructive technique.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: low
Risk score: 21
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References: None
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Impact
Version: 10
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Triage and analysis ### Investigating Modification of Boot Configuration Boot entry parameters, or boot parameters, are optional, system-specific settings that represent configuration options. These are stored in a boot configuration data (BCD) store, and administrators can use utilities like `bcdedit.exe` to configure these. This rule identifies the usage of `bcdedit.exe` to: - Disable Windows Error Recovery (recoveryenabled). - Ignore errors if there is a failed boot, failed shutdown, or failed checkpoint (bootstatuspolicy ignoreallfailures). These are common steps in destructive attacks by adversaries leveraging ransomware. #### Possible investigation steps - Investigate the script execution chain (parent process tree). - Identify the user account that performed the action and whether it should perform this kind of action. - Confirm whether the account owner is aware of the operation. - Investigate other alerts related to the user/host in the last 48 hours. - Check for similar behavior in other hosts on the environment. - Check if any files on the host machine have been encrypted. ### False positive analysis - The usage of these options is not inherently malicious. Administrators can modify these configurations to force a machine to boot for troubleshooting or data recovery purposes. ### Related rules - Deleting Backup Catalogs with Wbadmin - 581add16-df76-42bb-af8e-c979bfb39a59 ### Response and remediation - Initiate the incident response process based on the outcome of the triage. - Isolate the involved host to prevent destructive behavior, which is commonly associated with this activity. - Reset the password of the involved accounts. - If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities. ## Config 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.
Rule query
editprocess where event.type in ("start", "process_started") and (process.name : "bcdedit.exe" or process.pe.original_file_name == "bcdedit.exe") and (process.args : "/set" and process.args : "bootstatuspolicy" and process.args : "ignoreallfailures") or (process.args : "no" and process.args : "recoveryenabled")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Impact
- ID: TA0040
- Reference URL: https://attack.mitre.org/tactics/TA0040/
-
Technique:
- Name: Inhibit System Recovery
- ID: T1490
- Reference URL: https://attack.mitre.org/techniques/T1490/