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 local pySigma backend, then reveal pipelines only when you actually need them.

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Indexed Rules

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Backends

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pySigma Versions

Newest: 1.3.3

Translation Workspace

Shape the rule before it leaves Phoenix

Tune Translation

Active Rule

MaxMpxCt Registry Value Changed

pySigma version

Backend

Format

Target Profile

Splunk

Splunk through pysigma-backend-splunk.

Format Mode

Default

Default pySigma output mode for this backend.

Conversion Output

MaxMpxCt Registry Value Changed

Using Splunk · Default · pySigma 1.3.3

Translation controls

Adjust the rule on the left, then regenerate when you want a fresh backend-native query.

BackendSplunkFormatDefaultVersion1.3.3

title: MaxMpxCt Registry Value Changed
id: 0e6a9e62-627e-496c-aef5-bfa39da29b5e
status: test
description: |
    Detects changes to the "MaxMpxCt" registry value.
    MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate.
    Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
references:
    - https://www.huntress.com/blog/blackcat-ransomware-affiliate-ttps
    - https://securityscorecard.com/research/deep-dive-into-alphv-blackcat-ransomware
    - https://www.intrinsec.com/alphv-ransomware-gang-analysis/?cn-reloaded=1
    - https://www.sentinelone.com/labs/blackcat-ransomware-highly-configurable-rust-driven-raas-on-the-prowl-for-victims/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-03-19
tags:
    - attack.defense-evasion
    - attack.t1070.005
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|endswith: '\Services\LanmanServer\Parameters\MaxMpxCt'
    condition: selection
falsepositives:
    - Unknown
level: low

CLI command

Copy the exact command to reproduce this translation locally.

sigma convert --without-pipeline -t splunk -f default rules/windows/registry/registry_set/registry_set_optimize_file_sharing_network.yml