[metadata]
creation_date = "2023/09/28"
integration = ["endpoint"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2023/09/28"
bypass_bbr_timing = true

[rule]
author = ["Elastic"]
description = """
Identifies the execution of the built-in Windows Installer, msiexec.exe, to install a remote package. Adversaries may abuse
msiexec.exe to launch local or network accessible MSI files.
"""
from = "now-9m"
index = ["logs-endpoint.events.*"]
language = "eql"
license = "Elastic License v2"
name = "Potential Remote File Execution via MSIEXEC"
risk_score = 21
rule_id = "3e441bdb-596c-44fd-8628-2cfdf4516ada"
severity = "low"
tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Initial Access", "Tactic: Defense Evasion", "Rule Type: BBR", "Data Source: Elastic Defend"]
building_block_type = "default"
type = "eql"

query = '''
sequence with maxspan=1m
 [process where host.os.type == "windows" and event.action == "start" and
    process.name : "msiexec.exe" and process.args : "/V"] by process.entity_id
 [network where host.os.type == "windows" and process.name : "msiexec.exe" and
    event.action == "connection_attempted"] by process.entity_id
 [process where host.os.type == "windows" and event.action == "start" and
  process.parent.name : "msiexec.exe" and user.id : ("S-1-5-21-*", "S-1-5-12-1-*") and
  not process.executable : ("?:\\Windows\\SysWOW64\\msiexec.exe",
                            "?:\\Windows\\System32\\msiexec.exe",
                            "?:\\Windows\\System32\\srtasks.exe",
                            "?:\\Windows\\SysWOW64\\srtasks.exe",
                            "?:\\Windows\\System32\\taskkill.exe",
                            "?:\\Windows\\Installer\\MSI*.tmp",
                            "?:\\Program Files\\*.exe",
                            "?:\\Program Files (x86)\\*.exe",
                            "?:\\Windows\\System32\\ie4uinit.exe",
                            "?:\\Windows\\SysWOW64\\ie4uinit.exe",
                            "?:\\Windows\\System32\\sc.exe",
                            "?:\\Windows\\system32\\Wbem\\mofcomp.exe",
                            "?:\\Windows\\twain_32\\fjscan32\\SOP\\crtdmprc.exe",
                            "?:\\Windows\\SysWOW64\\taskkill.exe",
                            "?:\\Windows\\SysWOW64\\schtasks.exe",
                            "?:\\Windows\\system32\\schtasks.exe",
                            "?:\\Windows\\System32\\sdbinst.exe") and
  not (process.code_signature.subject_name == "Citrix Systems, Inc." and process.code_signature.trusted == true) and
  not (process.name : ("regsvr32.exe", "powershell.exe", "rundll32.exe", "wscript.exe") and
       process.Ext.token.integrity_level_name == "high" and
       process.args : ("?:\\Program Files\\*", "?:\\Program Files (x86)\\*")) and
  not (process.executable : ("?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe") and process.code_signature.trusted == true) and
  not (process.name : "rundll32.exe" and process.args : "printui.dll,PrintUIEntry")
  ] by process.parent.entity_id
'''

[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1566"
name = "Phishing"
reference = "https://attack.mitre.org/techniques/T1566/"
[[rule.threat.technique.subtechnique]]
id = "T1566.002"
name = "Spearphishing Link"
reference = "https://attack.mitre.org/techniques/T1566/002/"

[rule.threat.tactic]
id = "TA0001"
name = "Initial Access"
reference = "https://attack.mitre.org/tactics/TA0001/"

[[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/"