Suspicious MS Outlook Child Processedit

Identifies suspicious child processes of Microsoft Outlook. These child processes are often associated with spear phishing activity.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-windows.*

Severity: low

Risk score: 21

Runs every: 5m

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

Maximum alerts per execution: 100

References: None


  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Initial Access

Version: 10

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

## 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 queryedit

process where event.type in ("start", "process_started") and : "outlook.exe" and : ("Microsoft.Workflow.Compiler.exe", "arp.exe", "atbroker.exe", "bginfo.exe", "bitsadmin.exe",
                  "cdb.exe", "certutil.exe", "cmd.exe", "cmstp.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")