Mika Ayenson
a52751494e
* Convert config header to setup in note field * Parse note field into separate setup and note field with marko gfm * only validate and parse note on elastic authored rules and add CLI description for new DR_BYPASS_NOTE_VALIDATION_AND_PARSE environment variable Co-authored-by: brokensound77 <brokensound77@users.noreply.github.com>
59 lines
2.1 KiB
TOML
59 lines
2.1 KiB
TOML
[metadata]
|
|
creation_date = "2020/11/04"
|
|
maturity = "production"
|
|
updated_date = "2022/03/31"
|
|
|
|
[rule]
|
|
author = ["Elastic"]
|
|
description = """
|
|
Identifies unusual processes connecting to domains using known free SSL certificates. Adversaries may employ a known
|
|
encryption algorithm to conceal command and control traffic.
|
|
"""
|
|
from = "now-9m"
|
|
index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"]
|
|
language = "eql"
|
|
license = "Elastic License v2"
|
|
name = "Connection to Commonly Abused Free SSL Certificate Providers"
|
|
note = """## Setup
|
|
|
|
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.
|
|
"""
|
|
risk_score = 21
|
|
rule_id = "e3cf38fa-d5b8-46cc-87f9-4a7513e4281d"
|
|
severity = "low"
|
|
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Command and Control"]
|
|
timestamp_override = "event.ingested"
|
|
type = "eql"
|
|
|
|
query = '''
|
|
network 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")
|
|
'''
|
|
|
|
|
|
[[rule.threat]]
|
|
framework = "MITRE ATT&CK"
|
|
[[rule.threat.technique]]
|
|
id = "T1573"
|
|
name = "Encrypted Channel"
|
|
reference = "https://attack.mitre.org/techniques/T1573/"
|
|
|
|
|
|
[rule.threat.tactic]
|
|
id = "TA0011"
|
|
name = "Command and Control"
|
|
reference = "https://attack.mitre.org/tactics/TA0011/"
|
|
|