Execution via Microsoft DotNet ClickOnce Host

[metadata]
creation_date = "2023/09/25"
integration = ["endpoint"]
maturity = "production"
updated_date = "2026/03/24"

[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
Identifies the execution of DotNet ClickOnce installer via Dfsvc.exe trampoline. Adversaries may take advantage of
ClickOnce to proxy execution of malicious payloads via trusted Microsoft processes.
"""
from = "now-119m"
index = ["logs-endpoint.events.*"]
interval = "60m"
language = "eql"
license = "Elastic License v2"
name = "Execution via Microsoft DotNet ClickOnce Host"
risk_score = 21
rule_id = "5297b7f1-bccd-4611-93fa-ea342a01ff84"
severity = "low"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Defense Evasion",
    "Rule Type: BBR",
    "Data Source: Elastic Defend",
]
type = "eql"

query = '''
sequence by user.id with maxspan=5s
 [process where host.os.type == "windows" and event.action == "start" and
  process.name : "rundll32.exe" and process.command_line : ("*dfshim*ShOpenVerbApplication*", "*dfshim*#*")]
 [network where host.os.type == "windows" and process.name : "dfsvc.exe"]
'''


[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1127"
name = "Trusted Developer Utilities Proxy Execution"
reference = "https://attack.mitre.org/techniques/T1127/"

[[rule.threat.technique.subtechnique]]
id = "T1127.002"
name = "ClickOnce"
reference = "https://attack.mitre.org/techniques/T1127/002/"

[[rule.threat.technique]]
id = "T1218"
name = "System Binary Proxy Execution"
reference = "https://attack.mitre.org/techniques/T1218/"

[[rule.threat.technique.subtechnique]]
id = "T1218.011"
name = "Rundll32"
reference = "https://attack.mitre.org/techniques/T1218/011/"

[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"