Parent Process PID Spoofing

  1[metadata]
  2creation_date = "2021/07/14"
  3integration = ["endpoint"]
  4maturity = "production"
  5min_stack_comments = "New fields added: required_fields, related_integrations, setup"
  6min_stack_version = "8.3.0"
  7updated_date = "2024/03/28"
  8
  9[rule]
 10author = ["Elastic"]
 11description = """
 12Identifies parent process spoofing used to thwart detection. Adversaries may spoof the parent process identifier (PPID)
 13of a new process to evade process-monitoring defenses or to elevate privileges.
 14"""
 15from = "now-9m"
 16index = ["logs-endpoint.events.process-*"]
 17language = "eql"
 18license = "Elastic License v2"
 19name = "Parent Process PID Spoofing"
 20references = ["https://blog.didierstevens.com/2017/03/20/"]
 21risk_score = 73
 22rule_id = "c88d4bd0-5649-4c52-87ea-9be59dbfbcf2"
 23severity = "high"
 24tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Defense Evasion", "Tactic: Privilege Escalation", "Data Source: Elastic Defend"]
 25type = "eql"
 26
 27query = '''
 28/* This rule is compatible with Elastic Endpoint only */
 29
 30sequence by host.id, user.id with maxspan=3m 
 31
 32 [process where host.os.type == "windows" and event.type == "start" and
 33  process.Ext.token.integrity_level_name != "system" and 
 34  (
 35    process.pe.original_file_name : ("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe", "eqnedt32.exe",
 36                                     "fltldr.exe", "mspub.exe", "msaccess.exe", "powershell.exe", "pwsh.exe",
 37                                     "cscript.exe", "wscript.exe", "rundll32.exe", "regsvr32.exe", "msbuild.exe",
 38                                     "mshta.exe", "wmic.exe", "cmstp.exe", "msxsl.exe") or 
 39                                     
 40    (process.executable : ("?:\\Users\\*.exe",
 41                           "?:\\ProgramData\\*.exe",
 42                           "?:\\Windows\\Temp\\*.exe",
 43                           "?:\\Windows\\Tasks\\*") and 
 44      (process.code_signature.exists == false or process.code_signature.status : "errorBadDigest")) or 
 45                          
 46    process.executable : "?:\\Windows\\Microsoft.NET\\*.exe"                      
 47  ) and 
 48  
 49  not process.executable : 
 50             ("?:\\Windows\\System32\\WerFaultSecure.exe", 
 51              "?:\\WINDOWS\\SysWOW64\\WerFaultSecure.exe",
 52              "?:\\Windows\\System32\\WerFault.exe",
 53              "?:\\Windows\\SysWOW64\\WerFault.exe")
 54  ] by process.pid
 55 [process where host.os.type == "windows" and event.type == "start" and
 56  process.parent.Ext.real.pid > 0 and 
 57 
 58  /* process.parent.Ext.real.pid is only populated if the parent process pid doesn't match */
 59  not (process.name : "msedge.exe" and process.parent.name : "sihost.exe") and 
 60  
 61   not process.executable : 
 62             ("?:\\Windows\\System32\\WerFaultSecure.exe", 
 63              "?:\\WINDOWS\\SysWOW64\\WerFaultSecure.exe",
 64              "?:\\Windows\\System32\\WerFault.exe",
 65              "?:\\Windows\\SysWOW64\\WerFault.exe")
 66 ] by process.parent.Ext.real.pid
 67'''
 68
 69
 70[[rule.threat]]
 71framework = "MITRE ATT&CK"
 72[[rule.threat.technique]]
 73id = "T1134"
 74name = "Access Token Manipulation"
 75reference = "https://attack.mitre.org/techniques/T1134/"
 76[[rule.threat.technique.subtechnique]]
 77id = "T1134.004"
 78name = "Parent PID Spoofing"
 79reference = "https://attack.mitre.org/techniques/T1134/004/"
 80
 81
 82
 83[rule.threat.tactic]
 84id = "TA0005"
 85name = "Defense Evasion"
 86reference = "https://attack.mitre.org/tactics/TA0005/"
 87
 88
 89[[rule.threat]]
 90framework = "MITRE ATT&CK"
 91[[rule.threat.technique]]
 92id = "T1134"
 93name = "Access Token Manipulation"
 94reference = "https://attack.mitre.org/techniques/T1134/"
 95[[rule.threat.technique.subtechnique]]
 96id = "T1134.004"
 97name = "Parent PID Spoofing"
 98reference = "https://attack.mitre.org/techniques/T1134/004/"
 99
100
101
102[rule.threat.tactic]
103id = "TA0004"
104name = "Privilege Escalation"
105reference = "https://attack.mitre.org/tactics/TA0004/"