Suspicious Process Creation CallTraceedit

Identifies when a process is created and immediately accessed from an unknown memory code region and by the same parent process. This may indicate a code injection or hollowing attempt.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-windows.*

Severity: medium

Risk score: 43

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 4 (version history)

Added (Elastic Stack release): 8.0.0

Last modified (Elastic Stack release): 8.4.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

sequence by host.id with maxspan=1m [process where event.code == "1"
and /* sysmon process creation */ process.parent.name :
("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe",
"eqnedt32.exe", "fltldr.exe", "mspub.exe",
"msaccess.exe","cscript.exe", "wscript.exe", "rundll32.exe",
"regsvr32.exe", "mshta.exe", "wmic.exe",
"cmstp.exe", "msxsl.exe") and /* noisy FP patterns */ not
(process.parent.name : "EXCEL.EXE" and process.executable :
"?:\\Program Files\\Microsoft Office\\root\\Office*\\ADDINS\\*.exe")
and not (process.executable : "?:\\Windows\\splwow64.exe" and
process.args in ("8192", "12288") and process.parent.name :
("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe")) and
not (process.parent.name : "rundll32.exe" and process.parent.args : ("
?:\\WINDOWS\\Installer\\MSI*.tmp,zzzzInvokeManagedCustomActionOutOfPro
c", "--no-sandbox")) and not (process.executable :
("?:\\Program Files
(x86)\\Microsoft\\EdgeWebView\\Application\\*\\msedgewebview2.exe",
"?:\\Program Files\\Adobe\\Acrobat DC\\Acrobat\\Acrobat.exe",
"?:\\Windows\\SysWOW64\\DWWIN.EXE") and process.parent.name :
("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe")) and
not (process.parent.name : "regsvr32.exe" and process.parent.args :
("?:\\Program Files\\*", "?:\\Program Files (x86)\\*")) ] by
process.parent.entity_id, process.entity_id [process where
event.code == "10" and /* Sysmon process access event from unknown
module */ winlog.event_data.CallTrace : "*UNKNOWN*"] by
process.entity_id, winlog.event_data.TargetProcessGUID

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 4 (8.4.0 release)
  • Updated query, changed from:

    sequence by host.id with maxspan=1m [process where event.code == "1"
    and /* sysmon process creation */ process.parent.name :
    ("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe",
    "eqnedt32.exe", "fltldr.exe", "mspub.exe",
    "msaccess.exe", "powershell.exe", "pwsh.exe",
    "cscript.exe", "wscript.exe", "rundll32.exe", "regsvr32.exe",
    "mshta.exe", "wmic.exe", "cmstp.exe",
    "msxsl.exe")] by process.parent.entity_id, process.entity_id
    [process where event.code == "10" and /* Sysmon process access
    event from unknown module */ winlog.event_data.CallTrace :
    "*UNKNOWN*"] by process.entity_id, winlog.event_data.TargetProcessGUID
Version 2 (8.2.0 release)
  • Formatting only