Intelligence View
[$] A new API for tree-in-dcache filesystems
There are a number of kernel filesystems that store their directory entries directly in the directory-entry cache (dcache) without having any permanent storage for those objects. It started out as a "neat hack" for ramfs, Al Viro said, at…
directly in the directory-entry cache (dcache) without having any permanent
storage for those objects. It started out as a "neat hack" for ramfs,
Al Viro said, at the start of his filesystem-track session at
the
2024 Linux Storage,
Filesystem, Memory Management, and BPF Summit. Unfortunately, as the use
of this technique has grown into other filesystems, there has been a lot of
scope creep that has gotten out of control. He wanted to discuss some new
infrastructure that he is working on to try to clean some of that up.
1. Sofort-Triage & Abwehrmaßnahmen
SOC Incident Playbook: Vulnerability Remediation & Verification
title: Detect Exploitation - [$] A new API for tree-in-dcache filesystems
id: 88394b7f-7d22-4af9-9d65-fce734cefc26
status: experimental
description: Automatisch generierte SIEM-Erkennungsregel basierend auf CTI Intelligence
references:
- https://tsecurity.de/
author: iShareStuff CTI Automated Detection Engine
date: 2026-09-25
logsource:
category: network_connection
product: any
detection:
selection:
CommandLine|contains:
- 'exploit'
condition: selection
falsepositives:
- Legitime administrative Zugriffe oder Penetrationstests
level: high
tags:
- attack.initial_accessrule CTI_Threat_Indicator {
meta:
author = "iShareStuff CTI Automated Detection Engine"
date = "2026-09-25"
description = "YARA Signature for "
strings:
$str = "[$] A new API for tree-in-dcac" ascii wide
condition:
any of them
}index=security sourcetype IN ("cisco:asa", "pan:traffic", "zeek_conn", "suricata", "WinEventLog:Security")
("A new API for tree-in-dcache filesystems")
| stats count earliest(_time) as first_seen latest(_time) as last_seen by src_ip, dest_ip, dest_host, signature
| eval first_seen=strftime(first_seen, "%Y-%m-%d %H:%M:%S"), last_seen=strftime(last_seen, "%Y-%m-%d %H:%M:%S")
| sort - countmessage: "*A new API for tree-in-dcache filesystems*"CommonSecurityLog
| where Message has "A new API for tree-in-dcache filesystems"
| summarize EventCount = count(), FirstSeen = min(TimeGenerated), LastSeen = max(TimeGenerated) by SourceIP, DestinationIP, DestinationPort, Activity
| extend DetectionRule = "iShareStuff-CTI-Compiled"
| sort by EventCount desc2. Cyber Threat Intelligence & Forensik
MITRE ATT&CK Matrix Navigator 14 Taktiken
tsecurity.de Cognitive Threat RAG
Kognitive Analyse für identifizierte Bedrohung: Erhöhte Bedrohungslage im Bereich [$] A new API for tree-in-dcache filesys.... Basierend auf 368k Vektor-Korrelationen werden sofortige Isolationsmaßnahmen für betroffene Endpunkte empfohlen.
Netzwerk/Remote-Zugriff ohne Vorauthentifizierung möglich.
- 1. Perimeter-Inspektion: Relevante Portfreigaben und exponierte Endpunkte unverzüglich scannen.
- 2. Patch-Applikation: Hersteller-Hotfix einspielen oder betroffene Daemons in isolierte DMZ-Segmente überführen.
- 3. Telemetrie & EDR-Alerts: Prozessaufrufe und Child-Processes auf anomale Shell-Spawns überwachen.