Phoenix Studio
Convert indexed Sigma rules into analyst-ready detections.
This studio is built around Phoenix's own rule corpus, not a blank editor. Search by title or rule id, choose a live sigma-cli backend, then reveal pipelines only when you actually need them.
Indexed Rules
3,707
Ready to search
Backends
17
Live from sigconverter.io
CLI Versions
10
Newest: 2.0.2
Translation Workspace
Shape the rule before it leaves Phoenix
Tune Translation
Active Rule
Potential Base64 Encoded User-Agent
Target Profile
Splunk
Splunk SPL & tstats data model queries
Format Mode
Default
Plain SPL queries
Conversion Output
Potential Base64 Encoded User-Agent
Using Splunk · Default · sigma-cli 2.0.2
Translation controls
Adjust the rule on the left, then regenerate when you want a fresh backend-native query.
BackendSplunkFormatDefaultVersion2.0.2
title: Potential Base64 Encoded User-Agent
id: 894a8613-cf12-48b3-8e57-9085f54aa0c3
related:
- id: d443095b-a221-4957-a2c4-cd1756c9b747
type: derived
status: test
description: Detects User Agent strings that end with an equal sign, which can be a sign of base64 encoding.
references:
- https://blogs.jpcert.or.jp/en/2022/07/yamabot.html
- https://deviceatlas.com/blog/list-of-user-agent-strings#desktop
author: Florian Roth (Nextron Systems), Brian Ingram (update)
date: 2022-07-08
modified: 2023-05-04
tags:
- attack.command-and-control
- attack.t1071.001
logsource:
category: proxy
detection:
selection:
c-useragent|endswith: '='
condition: selection
falsepositives:
- Unknown
level: medium
CLI command
Copy the exact command to reproduce this translation locally.
sigma convert --without-pipeline -t splunk -f default rules/web/proxy_generic/proxy_ua_susp_base64.yml