IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Connection to Commonly Abused Free SSL Certificate Providers
editConnection to Commonly Abused Free SSL Certificate Providers
editIdentifies unusual processes connecting to domains using known free SSL certificates. Adversaries may employ a known encryption algorithm to conceal command and control traffic.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: low
Risk score: 21
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Command and Control
Version: 3 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 7.12.0
Rule authors: Elastic
Rule license: Elastic License v2
Rule query
editnetwork where network.protocol == "dns" and /* Add new free SSL certificate provider domains here */ dns.question.name : ("*letsencrypt.org", "*.sslforfree.com", "*.zerossl.com", "*.freessl.org") and /* Native Windows process paths that are unlikely to have network connections to domains secured using free SSL certificates */ process.executable : ("C:\\Windows\\System32\\*.exe", "C:\\Windows\\System\\*.exe", "C:\\Windows\\SysWOW64\\*.exe", "C:\\Windows\\Microsoft.NET\\Framework*\\*.exe", "C:\\Windows\\explorer.exe", "C:\\Windows\\notepad.exe") and /* Insert noisy false positives here */ not process.name : ("svchost.exe", "MicrosoftEdge*.exe", "msedge.exe")
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Encrypted Channel
- ID: T1573
- Reference URL: https://attack.mitre.org/techniques/T1573/
Rule version history
edit- Version 3 (7.12.0 release)
-
- Formatting only
- Version 2 (7.11.2 release)
-
- Formatting only