Detection rules › Splunk
Visio.exe File Download (PowerShell)
Visio.exe is a diagramming and vector graphics application developed by Microsoft, used for creating flowcharts, organizational charts, and other visual representations of information. Threat actors can abuse visio.exe to download files. This use case detects executions of visio.exe followed by URLs in the command line
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1105 Ingress Tool Transfer |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body yaml
id: '33361.59030'
title: Visio.exe File Download
description: Visio.exe is a diagramming and vector graphics application developed
by Microsoft, used for creating flowcharts, organizational charts, and other visual
representations of information. Threat actors can abuse visio.exe to download files.
This use case detects executions of visio.exe followed by URLs in the command line.
Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell`(TERM(EventCode=4103) OR
"<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") TERM(visio) | regex
process="(?i)visio(\.exe(\"|\'')?)?\s+(\"|\'')?[A-Za-z0-9]{2,6}:\/\/[^\s]+" | table
_time, host, user, process, process_* | bin span=1s | stats values(*) as * by _time,
host '
techniques:
- command-and-control:ingress tool transfer
technique_id:
- T1105
data_category:
- PowerShell logs
references:
- https://attack.mitre.org/techniques/T1105/
- https://lolbas-project.github.io/lolbas/OtherMSBinaries/Visio/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_powershell`(TERM(EventCode=4103) OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") TERM(visio)
Stage 2: regex
| regex process="(?i)visio(\.exe(\"|\')?)?\s+(\"|\')?[A-Za-z0-9]{2,6}:\/\/[^\s]+"
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>4103<" |
| 1 | TERM |
| 1 | "<EventID>4104<" |
| 1 | TERM |
| 1 | visio |