Suspicious MS Office Child Process

Identifies suspicious child processes of frequently targeted Microsoft Office applications (Word, PowerPoint, Excel). These child processes are often launched during exploitation of Office applications or from documents with malicious macros.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

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

Maximum alerts per execution: 100

References: None

Tags:

Elastic
Host
Windows
Threat Detection
Initial Access

Version: 11

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

edit

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule query

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process where event.type in ("start", "process_started") and
  process.parent.name : ("eqnedt32.exe", "excel.exe", "fltldr.exe", "msaccess.exe", "mspub.exe", "powerpnt.exe", "winword.exe", "outlook.exe") and
  process.name : ("Microsoft.Workflow.Compiler.exe", "arp.exe", "atbroker.exe", "bginfo.exe", "bitsadmin.exe", "cdb.exe", "certutil.exe",
                "cmd.exe", "cmstp.exe", "control.exe", "cscript.exe", "csi.exe", "dnx.exe", "dsget.exe", "dsquery.exe", "forfiles.exe",
                "fsi.exe", "ftp.exe", "gpresult.exe", "hostname.exe", "ieexec.exe", "iexpress.exe", "installutil.exe", "ipconfig.exe",
                "mshta.exe", "msxsl.exe", "nbtstat.exe", "net.exe", "net1.exe", "netsh.exe", "netstat.exe", "nltest.exe", "odbcconf.exe",
                "ping.exe", "powershell.exe", "pwsh.exe", "qprocess.exe", "quser.exe", "qwinsta.exe", "rcsi.exe", "reg.exe", "regasm.exe",
                "regsvcs.exe", "regsvr32.exe", "sc.exe", "schtasks.exe", "systeminfo.exe", "tasklist.exe", "tracert.exe", "whoami.exe",
                "wmic.exe", "wscript.exe", "xwizard.exe", "explorer.exe", "rundll32.exe", "hh.exe", "msdt.exe")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Initial Access
- ID: TA0001
- Reference URL: https://attack.mitre.org/tactics/TA0001/
Technique:
- Name: Phishing
- ID: T1566
- Reference URL: https://attack.mitre.org/techniques/T1566/
Sub-technique:
- Name: Spearphishing Attachment
- ID: T1566.001
- Reference URL: https://attack.mitre.org/techniques/T1566/001/

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