IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.

« Control Panel Process with Unusual Arguments Creation of Hidden Launch Agent or Daemon »

› › ›

Creation of Hidden Files and Directories via CommandLine

edit

Creation of Hidden Files and Directories via CommandLine

edit

Users can mark specific files as hidden simply by putting a "." as the first character in the file or folder name. Adversaries can use this to their advantage to hide files and folders on the system for persistence and defense evasion. This rule looks for hidden files or folders in common writable directories.

Rule type: eql

Rule indices:

auditbeat-*
logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 33

Tags:

Elastic
Host
Linux
Threat Detection
Defense Evasion

Version: 10 (version history)

Added (Elastic Stack release): 7.9.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

edit

Certain tools may create hidden temporary files or directories upon installation or as part of their normal behavior. These events can be filtered by the process arguments, username, or process name values.

Investigation guide

edit

Rule query

edit

process where event.type in ("start", "process_started") and
process.working_directory in ("/tmp", "/var/tmp", "/dev/shm") and
process.args regex~ """\.[a-z0-9_\-][a-z0-9_\-\.]{1,254}""" and not
process.name in ("ls", "find", "grep")

Threat mapping

edit

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Hide Artifacts
- ID: T1564
- Reference URL: https://attack.mitre.org/techniques/T1564/
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/

Rule version history

edit

Version 10 (8.4.0 release)

Rule name changed from: Creation of Hidden Files and Directories

Updated query, changed from:

process where event.type in ("start", "process_started") and
process.working_directory in ("/tmp", "/var/tmp", "/dev/shm") and
process.args regex~ """\.[a-z0-9_\-][a-z0-9_\-\.]{1,254}""" and not
process.name in ("ls", "find")

Version 8 (8.2.0 release)

Formatting only

Version 7 (7.14.0 release)

Updated query, changed from:

event.category:process AND event.type:(start or process_started) AND
process.working_directory:("/tmp" or "/var/tmp" or "/dev/shm") AND
process.args:/\.[a-zA-Z0-9_\-][a-zA-Z0-9_\-\.]{1,254}/ AND NOT
process.name:(ls or find)

Version 6 (7.12.0 release)

Formatting only

Version 5 (7.11.2 release)

Formatting only

Version 4 (7.11.0 release)

Formatting only

Version 3 (7.10.0 release)

Formatting only

Version 2 (7.9.1 release)

Formatting only

« Control Panel Process with Unusual Arguments Creation of Hidden Launch Agent or Daemon »