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/