Detection rules › Splunk
Net.exe Use with URL (Windows Event Log)
This use case detects net share commands mapping a drive to a URL as observed by the BumbleBee loader.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Lateral Movement | T1021.002 Remote Services: SMB/Windows Admin Shares |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '21865.38561'
title: Net.exe Use with URL
description: This use case detects net share commands mapping a drive to a URL as
observed by the BumbleBee loader.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) TERM(net) TERM(use) "://" | regex process="://"
| table _time, host, user process, process_* | bin span=1s | stats values(*) as
* by _time, host '
techniques:
- lateral-movement:remote services:smb/windows admin shares
technique_id:
- T1021.002
data_category:
- Process command-line parameters
- Windows event logs
references:
- https://twitter.com/Kostastsale/status/1701111694611898446
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) TERM(net) TERM(use) "://"
Stage 2: regex
| regex process="://"
Stage 3: table
| table _time, host, user process, process_*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4688<" |
| 1 | TERM |
| 1 | net |
| 1 | TERM |
| 1 | use |
| 1 | "://" |