Detection rules › Splunk
Network Connection with Suspicious Folder (Sysmon)
Detects potential downloads to suspicious file locations like temp, appdata, and downloads
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1105 Ingress Tool Transfer |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 3 | Network connection |
Rule body yaml
id: '9019.12092'
title: Network Connection with Suspicious Folder
description: 'Detects potential downloads to suspicious file locations like temp,
appdata, and downloads. - Threat Actor Association: Alloy Taurus/Gallium, Lazarus,
NewsPenguin, OilRig, TA413 - Software Association: LOWZERO, Vidar Stealer'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=3 OR "Event>ID<3")
("Temporary Internet Files" OR TERM("TEMP") OR TERM("Downloads") OR TERM("Appdata"))
| regex process="(?i)Temp|Downloads|Appdata" | table _time, host, user dest, direction,
event_id, eventtype, parent_*, process, process_*, user, user_id, src_*, dest_*
| bin span=1s | stats values(*) as * by _time, host, process '
techniques:
- command-and-control:ingress tool transfer
technique_id:
- T1105
data_category:
- Process use of network
- Windows Sysmon
references: null
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (EventCode=3 OR "Event>ID<3") ("Temporary Internet Files" OR TERM("TEMP") OR TERM("Downloads") OR TERM("Appdata"))
Stage 2: regex
| regex process="(?i)Temp|Downloads|Appdata"
Stage 3: table
| table _time, host, user dest, direction, event_id, eventtype, parent_*, process, process_*, user, user_id, src_*, dest_*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host, process
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 | "Event>ID<3" |
| 1 | "Temporary Internet Files" |
| 1 | "TEMP" |
| 1 | "Downloads" |
| 1 | "Appdata" |