Potential Suspicious DebugFS Root Device Accessedit
This rule monitors for the usage of the built-in Linux DebugFS utility to access a disk device without root permissions. Linux users that are part of the "disk" group have sufficient privileges to access all data inside of the machine through DebugFS. Attackers may leverage DebugFS in conjunction with "disk" permissions to read sensitive files owned by root, such as the shadow file, root ssh private keys or other sensitive files that may allow them to further escalate privileges.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
- endgame-*
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:
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Privilege Escalation
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
Version: 4
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule queryedit
process where host.os.type == "linux" and event.action in ("exec", "exec_event") and event.type == "start" and
process.name == "debugfs" and process.args : "/dev/sd*" and not process.args == "-R" and
not user.Ext.real.id == "0" and not group.Ext.real.id == "0"
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Valid Accounts
- ID: T1078
- Reference URL: https://attack.mitre.org/techniques/T1078/
-
Sub-technique:
- Name: Local Accounts
- ID: T1078.003
- Reference URL: https://attack.mitre.org/techniques/T1078/003/