Suspicious PDF Reader Child Process

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Identifies suspicious child processes of PDF reader applications. These child processes are often launched via exploitation of PDF applications or social engineering.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • 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

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Execution

Version: 8

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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## 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 : ("AcroRd32.exe",
                         "Acrobat.exe",
                         "FoxitPhantomPDF.exe",
                         "FoxitReader.exe") and
  process.name : ("arp.exe", "dsquery.exe", "dsget.exe", "gpresult.exe", "hostname.exe", "ipconfig.exe", "nbtstat.exe",
                  "net.exe", "net1.exe", "netsh.exe", "netstat.exe", "nltest.exe", "ping.exe", "qprocess.exe",
                  "quser.exe", "qwinsta.exe", "reg.exe", "sc.exe", "systeminfo.exe", "tasklist.exe", "tracert.exe",
                  "whoami.exe", "bginfo.exe", "cdb.exe", "cmstp.exe", "csi.exe", "dnx.exe", "fsi.exe", "ieexec.exe",
                  "iexpress.exe", "installutil.exe", "Microsoft.Workflow.Compiler.exe", "msbuild.exe", "mshta.exe",
                  "msxsl.exe", "odbcconf.exe", "rcsi.exe", "regsvr32.exe", "xwizard.exe", "atbroker.exe",
                  "forfiles.exe", "schtasks.exe", "regasm.exe", "regsvcs.exe", "cmd.exe", "cscript.exe",
                  "powershell.exe", "pwsh.exe", "wmic.exe", "wscript.exe", "bitsadmin.exe", "certutil.exe", "ftp.exe")

Framework: MITRE ATT&CKTM