[Rule Tuning] Tune "Telnet Port Activity" Rule for Accepted Connections Only (#2374)

* adjusted query to include event action and network direction filters

* adjusted rule name and file name

* toml linted and tags updated

Co-authored-by: Colson Wilhoit <48036388+DefSecSentinel@users.noreply.github.com>
This commit is contained in:
Terrance DeJesus
2022-11-07 14:00:25 -05:00
committed by GitHub
parent 25458123dd
commit fd1260c109
@@ -1,9 +1,9 @@
[metadata]
creation_date = "2020/02/18"
maturity = "production"
updated_date = "2022/08/24"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2022/10/20"
[rule]
author = ["Elastic"]
@@ -11,8 +11,8 @@ description = """
This rule detects network events that may indicate the use of Telnet traffic. Telnet is commonly used by system
administrators to remotely control older or embedded systems using the command line shell. It should almost never be
directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or
backdoor vector. As a plain-text protocol, it may also expose usernames and passwords to anyone capable of observing
the traffic.
backdoor vector. As a plain-text protocol, it may also expose usernames and passwords to anyone capable of observing the
traffic.
"""
false_positives = [
"""
@@ -26,18 +26,31 @@ from = "now-9m"
index = ["auditbeat-*", "filebeat-*", "packetbeat-*", "logs-endpoint.events.*"]
language = "kuery"
license = "Elastic License v2"
name = "Telnet Port Activity"
name = "Accepted Default Telnet Port Connection"
risk_score = 47
rule_id = "34fde489-94b0-4500-a76f-b8a157cf9269"
severity = "medium"
tags = ["Elastic", "Host", "Network", "Threat Detection", "Command and Control", "Host"]
tags = [
"Elastic",
"Host",
"Network",
"Threat Detection",
"Command and Control",
"Host",
"Lateral Movement",
"Initial Access",
]
timeline_id = "300afc76-072d-4261-864d-4149714bf3f1"
timeline_title = "Comprehensive Network Timeline"
timestamp_override = "event.ingested"
type = "query"
query = '''
event.category:(network or network_traffic) and network.transport:tcp and destination.port:23
event.category:(network or network_traffic) and destination.port:23
and network.direction:(inbound or ingress or outbound or egress)
and not event.action:(
flow_dropped or denied or deny or
flow_terminated or timeout or Reject or network_flow)
'''
@@ -45,30 +58,31 @@ event.category:(network or network_traffic) and network.transport:tcp and destin
framework = "MITRE ATT&CK"
[rule.threat.tactic]
reference = "https://attack.mitre.org/tactics/TA0011/"
id = "TA0011"
name = "Command and Control"
reference = "https://attack.mitre.org/tactics/TA0011/"
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
reference = "https://attack.mitre.org/techniques/T1021/"
id = "T1021"
name = "Remote Services"
reference = "https://attack.mitre.org/techniques/T1021/"
[rule.threat.tactic]
reference = "https://attack.mitre.org/tactics/TA0008/"
id = "TA0008"
name = "Lateral Movement"
reference = "https://attack.mitre.org/tactics/TA0008/"
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
reference = "https://attack.mitre.org/techniques/T1190/"
id = "T1190"
name = "Exploit Public-Facing Application"
reference = "https://attack.mitre.org/techniques/T1190/"
[rule.threat.tactic]
reference = "https://attack.mitre.org/tactics/TA0001/"
id = "TA0001"
name = "Initial Access"
reference = "https://attack.mitre.org/tactics/TA0001/"