Parent Process PID Spoofing

  1[metadata]
  2creation_date = "2021/07/14"
  3integration = ["endpoint"]
  4maturity = "production"
  5updated_date = "2024/05/21"
  6
  7[rule]
  8author = ["Elastic"]
  9description = """
 10Identifies parent process spoofing used to thwart detection. Adversaries may spoof the parent process identifier (PPID)
 11of a new process to evade process-monitoring defenses or to elevate privileges.
 12"""
 13from = "now-9m"
 14index = ["logs-endpoint.events.process-*"]
 15language = "eql"
 16license = "Elastic License v2"
 17name = "Parent Process PID Spoofing"
 18references = ["https://blog.didierstevens.com/2017/03/20/"]
 19risk_score = 73
 20rule_id = "c88d4bd0-5649-4c52-87ea-9be59dbfbcf2"
 21severity = "high"
 22tags = [
 23    "Domain: Endpoint",
 24    "OS: Windows",
 25    "Use Case: Threat Detection",
 26    "Tactic: Defense Evasion",
 27    "Tactic: Privilege Escalation",
 28    "Data Source: Elastic Defend",
 29]
 30type = "eql"
 31
 32query = '''
 33/* This rule is compatible with Elastic Endpoint only */
 34
 35sequence by host.id, user.id with maxspan=3m 
 36
 37 [process where host.os.type == "windows" and event.type == "start" and
 38  process.Ext.token.integrity_level_name != "system" and 
 39  (
 40    process.pe.original_file_name : ("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe", "eqnedt32.exe",
 41                                     "fltldr.exe", "mspub.exe", "msaccess.exe", "powershell.exe", "pwsh.exe",
 42                                     "cscript.exe", "wscript.exe", "rundll32.exe", "regsvr32.exe", "msbuild.exe",
 43                                     "mshta.exe", "wmic.exe", "cmstp.exe", "msxsl.exe") or 
 44                                     
 45    (process.executable : ("?:\\Users\\*.exe",
 46                           "?:\\ProgramData\\*.exe",
 47                           "?:\\Windows\\Temp\\*.exe",
 48                           "?:\\Windows\\Tasks\\*") and 
 49      (process.code_signature.exists == false or process.code_signature.status : "errorBadDigest")) or 
 50                          
 51    process.executable : "?:\\Windows\\Microsoft.NET\\*.exe"                      
 52  ) and 
 53  
 54  not process.executable : 
 55             ("?:\\Windows\\System32\\WerFaultSecure.exe", 
 56              "?:\\WINDOWS\\SysWOW64\\WerFaultSecure.exe",
 57              "?:\\Windows\\System32\\WerFault.exe",
 58              "?:\\Windows\\SysWOW64\\WerFault.exe")
 59  ] by process.pid
 60 [process where host.os.type == "windows" and event.type == "start" and
 61  process.parent.Ext.real.pid > 0 and 
 62 
 63  /* process.parent.Ext.real.pid is only populated if the parent process pid doesn't match */
 64  not (process.name : "msedge.exe" and process.parent.name : "sihost.exe") and 
 65  
 66   not process.executable : 
 67             ("?:\\Windows\\System32\\WerFaultSecure.exe", 
 68              "?:\\WINDOWS\\SysWOW64\\WerFaultSecure.exe",
 69              "?:\\Windows\\System32\\WerFault.exe",
 70              "?:\\Windows\\SysWOW64\\WerFault.exe")
 71 ] by process.parent.Ext.real.pid
 72'''
 73
 74
 75[[rule.threat]]
 76framework = "MITRE ATT&CK"
 77[[rule.threat.technique]]
 78id = "T1134"
 79name = "Access Token Manipulation"
 80reference = "https://attack.mitre.org/techniques/T1134/"
 81[[rule.threat.technique.subtechnique]]
 82id = "T1134.004"
 83name = "Parent PID Spoofing"
 84reference = "https://attack.mitre.org/techniques/T1134/004/"
 85
 86
 87
 88[rule.threat.tactic]
 89id = "TA0005"
 90name = "Defense Evasion"
 91reference = "https://attack.mitre.org/tactics/TA0005/"
 92[[rule.threat]]
 93framework = "MITRE ATT&CK"
 94[[rule.threat.technique]]
 95id = "T1134"
 96name = "Access Token Manipulation"
 97reference = "https://attack.mitre.org/techniques/T1134/"
 98[[rule.threat.technique.subtechnique]]
 99id = "T1134.004"
100name = "Parent PID Spoofing"
101reference = "https://attack.mitre.org/techniques/T1134/004/"
102
103
104
105[rule.threat.tactic]
106id = "TA0004"
107name = "Privilege Escalation"
108reference = "https://attack.mitre.org/tactics/TA0004/"