The SIEM app is now a part of the Elastic Security solution.
Click
here to view the current documentation.
IMPORTANT: No additional bug fixes or documentation updates will be released for this version.
IMPORTANT: No additional bug fixes or documentation updates will be released for this version.
Base64 Encoding/Decoding Activity
editBase64 Encoding/Decoding Activity
editIdentifies attempts to encode and decode data, a technique adversaries can use to evade detection by host- or network-based security controls.
Rule type: query
Rule indices:
- auditbeat-*
Severity: low
Risk score: 21
Runs every: 5 minutes
Searches indices from: now-6m (Date Math format, see also Additional look-back time)
Maximum signals per execution: 100
Tags:
- Elastic
- Linux
Version: 1
Added (Elastic Stack release): 7.8.0
Potential false positives
editAutomated tools such as Jenkins may encode or decode files as part of their normal behavior. These events can be filtered by the process executable or username values.
Rule query
editevent.action:(executed or process_started) and process.name:(base64 or base64plain or base64url or base64mime or base64pem)
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Deobfuscate/Decode Files or Information
- ID: T1140
- Reference URL: https://attack.mitre.org/techniques/T1140/
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Obfuscated Files or Information
- ID: T1027
- Reference URL: https://attack.mitre.org/techniques/T1027/