The following detection identifies Microsoft Excel spawning Windows Script Host -
wscript.exe. Typically, this is not common behavior and not default with Excel.exe. Excel.exe will generally be found in the following path
C:\Program Files\Microsoft Office\root\Office16 (version will vary).
wscript.exe default location is
c:\windows\system32\ or c:windows\syswow64
or wscript.exe` spawning from Excel.exe is common for a spearphishing attachment and is actively used. Albeit, the command-line executed will most likely be obfuscated and captured via another detection. During triage, review parallel processes and identify any files that may have been written. Review the reputation of the remote destination and block accordingly.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-04-12
- Author: Michael Haag, Splunk
- ID: 57fe880a-9be3-11eb-9bf3-acde48001122
Kill Chain Phase
1 2 3 4 5 6 | tstats `security_content_summariesonly` count values(Processes.process) min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name="excel.exe" Processes.process_name IN ("cscript.exe", "wscript.exe") by Processes.parent_process Processes.process_name Processes.user Processes.dest | `drop_dm_object_name("Processes")` | `security_content_ctime(firstTime)` |`security_content_ctime(lastTime)` | `excel_spawning_windows_script_host_filter`
The SPL above uses the following Macros:
excel_spawning_windows_script_host_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the
Endpoint datamodel in the
Known False Positives
False positives should be limited, but if any are present, filter as needed. In some instances,
cscript.exe is used for legitimate business practices.
Associated Analytic Story
|80.0||80||100||An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$, indicating potential suspicious macro execution.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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