Windows Installer with Suspicious Properties

[metadata]
creation_date = "2023/09/26"
integration = ["endpoint"]
maturity = "production"
updated_date = "2026/07/28"

[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
Identifies the execution of an installer from an archive or with suspicious properties. Adversaries may abuse
msiexec.exe to launch local or network accessible MSI files in an attempt to bypass application whitelisting.
"""
from = "now-119m"
index = ["logs-endpoint.events.*"]
interval = "60m"
language = "eql"
license = "Elastic License v2"
name = "Windows Installer with Suspicious Properties"
references = ["https://lolbas-project.github.io/lolbas/Binaries/Msiexec/"]
risk_score = 21
rule_id = "55f07d1b-25bc-4a0f-aa0c-05323c1319d0"
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 host.id with maxspan=1m
  [registry where host.os.type == "windows" and event.type == "change" and process.name : "msiexec.exe" and
   (
    (registry.value : "InstallSource" and
     registry.data.strings : ("?:\\Users\\*\\Temp\\Temp?_*.zip\\*",
                             "?:\\Users\\*\\*.7z\\*",
                             "?:\\Users\\*\\*.rar\\*")) or

    (registry.value : ("DisplayName", "ProductName") and registry.data.strings : "SetupTest")
    )]
  [process where host.os.type == "windows" and event.action == "start" and
    process.parent.name : "msiexec.exe" and
    not process.name : "msiexec.exe" and
    not (process.executable : ("?:\\Program Files (x86)\\*.exe", "?:\\Program Files\\*.exe") and process.code_signature.trusted == true)]
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1218"
name = "System Binary Proxy Execution"
reference = "https://attack.mitre.org/techniques/T1218/"
[[rule.threat.technique.subtechnique]]
id = "T1218.007"
name = "Msiexec"
reference = "https://attack.mitre.org/techniques/T1218/007/"



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