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
Suspicious FromBase64String Usage On Gzip Archive - Ps Script
Target Profile
Splunk
Splunk SPL & tstats data model queries
Format Mode
Default
Plain SPL queries
Conversion Output
Suspicious FromBase64String Usage On Gzip Archive - Ps Script
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: Suspicious FromBase64String Usage On Gzip Archive - Ps Script
id: df69cb1d-b891-4cd9-90c7-d617d90100ce
related:
- id: d75d6b6b-adb9-48f7-824b-ac2e786efe1f
type: similar
status: test
description: Detects attempts of decoding a base64 Gzip archive in a PowerShell script. This technique is often used as a method to load malicious content into memory afterward.
references:
- https://speakerdeck.com/heirhabarov/hunting-for-powershell-abuse?slide=43
author: frack113
date: 2022-12-23
tags:
- attack.command-and-control
- attack.t1132.001
logsource:
product: windows
category: ps_script
definition: 'Requirements: Script Block Logging must be enabled'
detection:
selection:
ScriptBlockText|contains|all:
- 'FromBase64String'
- 'MemoryStream'
- 'H4sI'
condition: selection
falsepositives:
- Legitimate administrative script
level: medium
CLI command
Copy the exact command to reproduce this translation locally.
sigma convert --without-pipeline -t splunk -f default rules/windows/powershell/powershell_script/posh_ps_frombase64string_archive.yml