Suspicious Parent-Child Relationship

[rule]
description = """
Identifies Windows programs run with unexpected parent processes, which can indicate masquerading via process hollowing
or other forms of code injection in an attempt to evade detections that monitor the execution from suspicious locations.
"""
id = "18a26e3e-e535-4d23-8ffa-a3cdba56d16e"
license = "Elastic License v2"
name = "Suspicious Parent-Child Relationship"
os_list = ["windows"]
reference = [
    "https://www.elastic.co/security-labs/bits-and-bytes-analyzing-bitsloth",
    "https://www.elastic.co/security-labs/elastic-security-labs-discovers-lobshot-malware",
    "https://www.elastic.co/security-labs/elastic-security-labs-steps-through-the-r77-rootkit",
]
version = "1.0.44"

query = '''
process where event.action == "start" and
 process.executable : ("?:\\*", "\\Device\\CdRom*", "\\Device\\Mup\\*", "\\\\*") and
 process.parent.executable : ("?:\\*", "\\Device\\CdRom*", "\\Device\\Mup\\*", "\\\\*") and
  (
   /*
     suspicious parent processes
     N.B svchost.exe is covered by ruleId 5b00c9ba-9546-47cc-8f9f-1c1a3e95f65c

    */
   (process.name : "autochk.exe" and not process.parent.name : "smss.exe") or

   (process.name : ("consent.exe", "RuntimeBroker.exe") and not process.parent.name : ("svchost.exe", "RuntimeBroker.exe") and
    not process.parent.executable :
                 ("?:\\Program Files\\ThreatLocker\\threatlockerconsent.exe",
                  "?:\\Program Files (x86)\\Workplace\\Components\\WorkplaceContainerComponent\\Current\\Workplace Container Helper.exe")) or
   (process.name : "SearchIndexer.exe" and not process.parent.name : ("services.exe", "SearchIndexer.exe")) or
   (process.name : "smss.exe" and not process.parent.name : ("System", "smss.exe", "sihost.exe")) or
   (process.name : "wininit.exe" and not process.parent.name : "smss.exe") or
   (process.name : ("lsass.exe", "LsaIso.exe") and not process.parent.name : ("wininit.exe", "lsass.exe", "services.exe")) or
   (process.name : "services.exe" and not process.parent.name : "wininit.exe") or
   (process.name : "spoolsv.exe" and not process.parent.name : ("services.exe", "spoolsv.exe")) or
   (process.name : "taskhost.exe" and not process.parent.name : ("services.exe", "svchost.exe")) or
   (process.name : "taskhostw.exe" and not process.parent.name : ("services.exe", "svchost.exe", "taskhostw.exe")) or
   (process.name : ("wmiprvse.exe", "wsmprovhost.exe", "winrshost.exe") and not process.parent.name : "svchost.exe") or
   (process.name : "sihost.exe" and not process.parent.name : ("svchost.exe", "sihost.exe", "powershell.exe")) or
   (process.name : ("winlogon.exe", "csrss.exe", "SearchProtocolHost.exe", "fontdrvhost.exe", "userinit.exe", "dwm.exe", "LogonUI.exe", "taskhostw.exe") and
    (process.parent.executable : ("?:\\Users\\*\\AppData\\*", "?:\\Users\\Public\\*", "?:\\Users\\*\\Downloads\\*", "?:\\ProgramData\\*",
                                 "?:\\Windows\\Temp\\*", "?:\\Users\\*\\Desktop\\*", "\\Device\\CdRom*", "\\Device\\Mup\\*") or
     process.parent.name : ("python*", "powershell.exe", "rundll32.exe", "regsvr32.exe"))) or

   /* suspicious child processes */
   (process.parent.name : "lsass.exe" and not process.name : ("lsass.exe", "WerFaultSecure.exe", "WerFault.exe", "efsui.exe", "LsaIso.exe") and
    not (process.code_signature.subject_name in ("NoMachine S.a.r.l.", "AuthLite, LLC") and process.code_signature.trusted == true) and
    not process.hash.sha256 : ("bfcb8f057dae3df9c656ec983d165c1571dbb5e19b6310cc0e5f1bff4c063c1e",
                               "dd1731be5fccca0d15f2c8e4780debc2962e4c434a7a138fff631a6aa0165962",
                               "67f366015d701dcd609e1f40c6bcbe56e7d2b479ebc4229927e50674769a8ead")) or
   (process.parent.name : "autochk.exe" and not process.name:("chkdsk.exe", "doskey.exe", "WerFault.exe", "conhost.exe")) or
   (process.parent.name : "smss.exe" and
    not process.name : ("autochk.exe", "smss.exe", "csrss.exe", "wininit.exe", "winlogon.exe", "setupcl.exe", "WerFault.exe"))
   )
   and not process.parent.executable :
                   ("?:\\Program Files\\Adobe\\Acrobat DC\\Acrobat\\AcroCEF\\AcroCEF.exe",
                    "?:\\Program Files (x86)\\Adobe\\Acrobat DC\\Acrobat\\*\\AcroCEF.exe",
                    "?:\\Program Files (x86)\\Adobe\\Acrobat Reader DC\\Reader\\AcroCEF\\RdrCEF.exe",
                    "?:\\Program Files\\Adobe\\Acrobat Reader DC\\Reader\\AcroCEF\\RdrCEF.exe") and
   not (process.name : "dwm.exe" and process.code_signature.subject_name == "Teramind Inc." and process.code_signature.trusted == true) and
   not (process.name : "SearchProtocolHost.exe" and process.parent.name : "rundll32.exe" and process.parent.args : "AppXDeploymentExtensions.OneCore.dll,ShellRefresh") and
   not (process.parent.executable : "?:\\Windows\\System32\\smss.exe" and process.parent.args : "-SpecialSession") and
   not (process.parent.executable : ("?:\\Program Files\\Sandboxie\\SandboxieDcomLaunch.exe", "?:\\Program Files\\Sandboxie-Plus\\SandboxieDcomLaunch.exe") and process.name : "RuntimeBroker.exe") and
   not (process.name : ("winlogon.exe", "csrss.exe") and
        process.parent.executable : "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\OneDrive.exe" and
        process.parent.args : "/client=Personal" and process.parent.args : "/background") and
   not (process.executable : "?:\\Windows\\System32\\wbem\\WmiPrvSE.exe" and process.args : "/regserver" and
        process.Ext.token.integrity_level_name : "system") and
   not (process.name : "consent.exe" and
        process.parent.executable : "?:\\Program Files (x86)\\Common Files\\Adobe\\Adobe Desktop Common\\ADS\\CRWindowsClientService.exe") and
   not (process.parent.executable : "?:\\Users\\*\\AppData\\Local\\Microsoft\\EdgeUpdate\\*\\MicrosoftEdgeUpdateCore.exe" and
        process.executable : "?:\\WINDOWS\\system32\\SearchProtocolHost.exe" and process.command_line : "*UsGthrFltPipeMssGthrPipe*") and
   not (process.executable : "?:\\Windows\\System32\\SearchProtocolHost.exe" and
        process.parent.executable : ("?:\\Users\\*\\AppData\\Local\\Microsoft\\Teams\\current\\Teams.exe", "C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe")) and
   not (process.name : "cmd.exe" and process.parent.executable : "?:\\Windows\\System32\\lsass.exe" and
        process.args : "C:\\AdPasswordSync\\passwd.bat") and
   not (process.executable :
                ("?:\\Program Files (x86)\\Tanium\\Tanium Client\\Patch\\tools\\TaniumFileInfo.exe",
                 "?:\\Program Files (x86)\\VIPRE Business Agent\\UrlInspectAddon.exe") and process.parent.name : "smss.exe") and
   not (process.parent.name : "lsass.exe" and
        process.executable : "?:\\Program Files\\McAfee\\Endpoint Encryption Agent\\MfeEpeHost.exe") and
   not (process.parent.name : "lsass.exe" and process.code_signature.subject_name == "Secure Endpoints Inc." and process.code_signature.trusted == true) and
   not (process.name : "consent.exe" and process.parent.name : "rundll32.exe" and
        process.parent.args == "shell32.dll,SHCreateLocalServerRunDll" and process.parent.args == "{9BA05972-F6A8-11CF-A442-00A0C90A8F39}") and
   not (process.executable : ("?:\\Windows\\System32\\spoolsv.exe", "?:\\Windows\\System32\\RuntimeBroker.exe") and
        process.parent.executable : ("?:\\Program Files (x86)\\Workplace\\Components\\WorkplaceContainerComponent\\Current\\Workplace Starter.exe",
                                     "?:\\Program Files (x86)\\Workplace\\Components\\WorkplaceContainerComponent\\Current\\Workplace Container Helper.exe")) and
   not (process.executable : "C:\\Windows\\Sys?????\\wbem\\WmiPrvSE.exe" and process.args : "/RegServer" and process.parent.name : ("powershell.exe", "cmd.exe")) and 
   not (process.parent.name == "lsass.exe" and process.args : "C:\\Program Files\\PasswordRBL\\passwdfw.ps1") and
   not (process.name : "services.exe" and process.parent.executable : "?:\\Windows\\LFSAgent\\lasrv.exe" and
        process.code_signature.trusted == true and
        process.code_signature.subject_name : "LEPIDE SOFTWARE PRIVATE LIMITED") and
   not (process.name : "LogonUI.exe" and process.parent.executable : "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\*\\FileCoAuth.exe")
'''

min_endpoint_version = "7.15.0"
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[optional_actions]]
action = "rollback"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1036"
name = "Masquerading"
reference = "https://attack.mitre.org/techniques/T1036/"

[[threat.technique]]
id = "T1055"
name = "Process Injection"
reference = "https://attack.mitre.org/techniques/T1055/"
[[threat.technique.subtechnique]]
id = "T1055.012"
name = "Process Hollowing"
reference = "https://attack.mitre.org/techniques/T1055/012/"



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

[internal]
min_endpoint_version = "7.15.0"