Command Shell Activity Started via RunDLL32

  1[metadata]
  2creation_date = "2020/10/19"
  3integration = ["endpoint", "windows"]
  4maturity = "production"
  5updated_date = "2024/05/21"
  6
  7[rule]
  8author = ["Elastic"]
  9description = "Identifies command shell activity started via RunDLL32, which is commonly abused by attackers to host malicious code."
 10false_positives = ["Microsoft Windows installers leveraging RunDLL32 for installation."]
 11from = "now-9m"
 12index = ["winlogbeat-*", "logs-endpoint.events.process-*", "logs-windows.sysmon_operational-*", "endgame-*"]
 13language = "eql"
 14license = "Elastic License v2"
 15name = "Command Shell Activity Started via RunDLL32"
 16risk_score = 21
 17rule_id = "9ccf3ce0-0057-440a-91f5-870c6ad39093"
 18setup = """## Setup
 19
 20If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
 21events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
 22Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
 23`event.ingested` to @timestamp.
 24For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
 25"""
 26severity = "low"
 27tags = [
 28    "Domain: Endpoint",
 29    "OS: Windows",
 30    "Use Case: Threat Detection",
 31    "Tactic: Execution",
 32    "Tactic: Credential Access",
 33    "Tactic: Defense Evasion",
 34    "Data Source: Elastic Endgame",
 35    "Data Source: Elastic Defend",
 36    "Data Source: Sysmon",
 37]
 38timestamp_override = "event.ingested"
 39type = "eql"
 40
 41query = '''
 42process where host.os.type == "windows" and event.type == "start" and
 43 process.name : ("cmd.exe", "powershell.exe") and
 44  process.parent.name : "rundll32.exe" and process.parent.command_line != null and
 45  /* common FPs can be added here */
 46  not process.parent.args : ("C:\\Windows\\System32\\SHELL32.dll,RunAsNewUser_RunDLL",
 47                             "C:\\WINDOWS\\*.tmp,zzzzInvokeManagedCustomActionOutOfProc")
 48'''
 49
 50
 51[[rule.threat]]
 52framework = "MITRE ATT&CK"
 53[[rule.threat.technique]]
 54id = "T1059"
 55name = "Command and Scripting Interpreter"
 56reference = "https://attack.mitre.org/techniques/T1059/"
 57[[rule.threat.technique.subtechnique]]
 58id = "T1059.001"
 59name = "PowerShell"
 60reference = "https://attack.mitre.org/techniques/T1059/001/"
 61
 62[[rule.threat.technique.subtechnique]]
 63id = "T1059.003"
 64name = "Windows Command Shell"
 65reference = "https://attack.mitre.org/techniques/T1059/003/"
 66
 67
 68
 69[rule.threat.tactic]
 70id = "TA0002"
 71name = "Execution"
 72reference = "https://attack.mitre.org/tactics/TA0002/"
 73[[rule.threat]]
 74framework = "MITRE ATT&CK"
 75[[rule.threat.technique]]
 76id = "T1552"
 77name = "Unsecured Credentials"
 78reference = "https://attack.mitre.org/techniques/T1552/"
 79
 80
 81[rule.threat.tactic]
 82id = "TA0006"
 83name = "Credential Access"
 84reference = "https://attack.mitre.org/tactics/TA0006/"
 85[[rule.threat]]
 86framework = "MITRE ATT&CK"
 87[[rule.threat.technique]]
 88id = "T1218"
 89name = "System Binary Proxy Execution"
 90reference = "https://attack.mitre.org/techniques/T1218/"
 91[[rule.threat.technique.subtechnique]]
 92id = "T1218.011"
 93name = "Rundll32"
 94reference = "https://attack.mitre.org/techniques/T1218/011/"
 95
 96
 97
 98[rule.threat.tactic]
 99id = "TA0005"
100name = "Defense Evasion"
101reference = "https://attack.mitre.org/tactics/TA0005/"