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Description

The following analytic identifies native living off the land binaries within the Windows operating system that may be abused by adversaries by moving it to a new directory. The list of binaries was derived from the https://lolbas-project.github.io site, and excluded common process names (cmd.exe, explorer.exe, csc.exe, hh.exe, regedit.exe) and DotNet binaries. It also does not include the category of OtherMSBinaries.

  • Type: Anomaly
  • Product: Splunk Behavioral Analytics
  • Datamodel: Endpoint_Processes
  • Last Updated: 2022-08-31
  • Author: Michael Haag, Splunk
  • ID: 25689101-012a-324a-94d3-08301e6c065a

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1036 Masquerading Defense Evasion
T1036.003 Rename System Utilities Defense Evasion
T1218 System Binary Proxy Execution Defense Evasion
T1218.004 InstallUtil Defense Evasion
Kill Chain Phase
  • Actions on Objectives
NIST
  • PR.PT
  • DE.CM
CIS20
  • CIS 8
CVE 


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 $ssa_input = 
| from read_ssa_enriched_events() 
| eval device=ucast(map_get(input_event, "dest_device_id"), "string", null), user=ucast(map_get(input_event, "dest_user_id"), "string", null), timestamp=parse_long(ucast(map_get(input_event, "_time"), "string", null)), process_name=lower(ucast(map_get(input_event, "process_name"), "string", null)), process_path=lower(ucast(map_get(input_event, "process_path"), "string", null)), event_id=ucast(map_get(input_event, "event_id"), "string", null);
$cond_1 = 
| from $ssa_input 
| where process_name="bitsadmin.exe" OR process_name="certoc.exe" OR process_name="certreq.exe" OR process_name="certutil.exe" OR process_name="cmdkey.exe" OR process_name="cmdl32.exe" OR process_name="cmstp.exe" OR process_name="configsecuritypolicy.exe" OR process_name="control.exe" OR process_name="cscript.exe" OR process_name="datasvcutil.exe" OR process_name="desktopimgdownldr.exe" OR process_name="dfsvc.exe" OR process_name="diantz.exe" OR process_name="diskshadow.exe" OR process_name="dllhost.exe" OR process_name="dnscmd.exe" OR process_name="esentutl.exe" OR process_name="eventvwr.exe" OR process_name="expand.exe" OR process_name="extexport.exe" OR process_name="extrac32.exe" OR process_name="findstr.exe" OR process_name="finger.exe" OR process_name="fltmc.exe" OR process_name="forfiles.exe" OR process_name="ftp.exe" OR process_name="gfxdownloadwrapper.exe" OR process_name="gpscript.exe" OR process_name="imewdbld.exe" OR process_name="ie4uinit.exe" OR process_name="ieexec.exe" OR process_name="ilasm.exe" OR process_name="infdefaultinstall.exe" OR process_name="makecab.exe" OR process_name="mavinject.exe" OR process_name="microsoft.workflow.compiler.exe" OR process_name="mmc.exe" OR process_name="msconfig.exe" OR process_name="msdt.exe" OR process_name="mshta.exe" OR process_name="msiexec.exe" OR process_name="netsh.exe" OR process_name="odbcconf.exe" OR process_name="offlinescannershell.exe" OR process_name="pcalua.exe" OR process_name="pcwrun.exe" OR process_name="pktmon.exe" OR process_name="pnputil.exe" OR process_name="presentationhost.exe" OR process_name="print.exe" OR process_name="printbrm.exe" OR process_name="psr.exe" OR process_name="rasautou.exe" OR process_name="reg.exe" OR process_name="regini.exe" OR process_name="register-cimprovider.exe" OR process_name="regsvr32.exe" OR process_name="replace.exe" OR process_name="rpcping.exe" OR process_name="rundll32.exe" OR process_name="runonce.exe" OR process_name="runscripthelper.exe" OR process_name="sc.exe" OR process_name="schtasks.exe" OR process_name="scriptrunner.exe" OR process_name="settingsynchost.exe" OR process_name="syncappvpublishingserver.exe" OR process_name="ttdinject.exe" OR process_name="tttracer.exe" OR process_name="vbc.exe" OR process_name="verclsid.exe" OR process_name="wab.exe" OR process_name="wlrmdr.exe" OR process_name="wmic.exe" OR process_name="workfolders.exe" OR process_name="wscript.exe" OR process_name="wsreset.exe" OR process_name="wuauclt.exe" OR process_name="xwizard.exe";

| from $cond_1 
| where match_regex(process_path, /(?i)\\windows\\system32/)=false AND match_regex(process_path, /(?i)\\windows\\syswow64/)=false AND match_regex(process_path, /(?i)\\windows\\adws/)=false AND match_regex(process_path, /(?i)\\windows\\networkcontroller/)=false AND match_regex(process_path, /(?i)\\windows\\systemapps/)=false AND match_regex(process_path, /(?i)\\winsxs/)=false AND match_regex(process_path, /(?i)\\microsoft.net/)=false 
| eval start_time=timestamp, end_time=timestamp, entities=mvappend(device, user), body=create_map(["event_id", event_id, "process_path", process_path, "process_name", process_name]) 
| into write_ssa_detected_events();

Macros

The SPL above uses the following Macros:

:information_source: windows_lolbin_binary_in_non_standard_path_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • dest_device_id
  • process_name
  • _time
  • dest_user_id
  • process_path
  • cmd_line

How To Implement

Collect endpoint data such as sysmon or 4688 events.

Known False Positives

False positives may be present and filtering may be required. Certain utilities will run from non-standard paths based on the third-party application in use.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 A system process $process_name$ with commandline $cmd_line$ spawn in non-default folder path on host $dest_device_id$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 4