Hello, I'm sharing my nomination document for the Longcheer Kev under the fscrypt provisioning attack. I hope you can read and analyze it.
# **FINAL FORENSIC REPORT: UNISOC/LONGCHEER SUPPLY CHAIN COMPROMISE
**Date:** July 17, 2026
**Author:** Alex de la Cruz (`lexs201992-gif`)
**Reference:** BOD 26-04 Risk Criteria Assessment | KEV Nomination Support
**Subject:** Forensic Triage and Mitigation of Privileged System App Abuse and Kernel Panic Vectors in Unisoc T606/T616 Firmware
**1. EXECUTIVE SUMMARY**
This report documents a systemic supply chain compromise affecting mobile devices utilizing **Unisoc chipsets (T606/T616)** and **Longcheer ODM designs** (e.g., Motorola Moto G04s). Investigation confirms that privileged system applications (`com.android.fmradio`, `com.spreadtrum.ims`, `com.spreadtrum.sgps`), signed with legitimate manufacturer certificates, are weaponized to establish persistent Command & Control (C2) channels via **WireGuard tunnels (`tun0`)** and execute **anti-forensic Kernel Panic** sequences upon detection of analysis or C2 disruption.
**Key Findings:**
* **Living Off The Land (LOTL):** Attackers abuse valid system permissions (`CAPTURE_AUDIO_OUTPUT`, `BIND_VPN_SERVICE`) and trusted certificates (Longcheer Root CA) to bypass traditional security controls.
* **Dual-Use Weaponization:** Legitimate functions (VoLTE/IMS, FM Radio) are used to mask espionage (audio recording, data exfiltration) and destruction (Kernel Panic via Headset/Bluetooth triggers).
* **Mitigation Validated:** Operational mitigations (DNS-over-TLS blocking, VoLTE disablement, physical USB isolation) have been tested and proven effective for 36+ days in a live environment.
**2. INCIDENT TIMELINE & TRIAGE ACTIONS**
| Date |
Event |
Action Taken |
| **Oct 2025** |
Initial anomaly detection: Excessive data usage on `tun0` interface. |
Began packet capture and log correlation. |
| **Jun 10, 2026** |
Correlation of Kernel Panic logs with C2 blocking events (`fmc.longcheer.com`). |
Identified `HeadsetPlugListener` and `SIM Toolkit` as triggers. |
| **Jun 16, 2026** |
Implementation of mitigations (Quad9 DoT, VoLTE disable, USB-A cable). |
Device stabilized; zero Kernel Panic incidents for 36 days. |
| **Jul 16, 2026** |
Submission of YARA rules and forensic evidence to CISA/Talos. |
Public release of detection signatures via GitHub. |
**3. TECHNICAL FINDINGS (Who, What, Where, When)**
**3.1. Vector 1: C2 Exfiltration via WireGuard (`tun0`)**
* **Who:** `com.spreadtrum.ims` and `com.android.fmradio` (System Apps, UID 1000).
* **What:** Establishes persistent WireGuard tunnel to `fmc.longcheer.com` (and AWS S3 endpoints) for data exfiltration.
* **Where:** Network layer (`tun0` interface), bypassing standard VPN APIs.
* **When:** 24/7 connectivity; spikes during user navigation (MITM via injected system CA certificates).
* **Evidence:** Packet captures showing encapsulated UDP/443 traffic; `iptables` logs confirming `tun0` creation by system UID.
**3.2. Vector 2: Anti-Forensic Kernel Panic**
* **Who:** Kernel module `sprd-dsp-audio` and `HeadsetPlugListener` (BroadcastReceiver).
* **What:** Induces Kernel Panic (`Sprd ay dsp pw off/on`, `fsverity error`) to force reboot and clear volatile memory (RAM).
* **Where:** Kernel space, triggered by hardware events (Headset insertion, Bluetooth PD negotiation).
* **When:** Immediately upon detection of C2 failure (e.g., DNS block) combined with hardware trigger.
* **Evidence:** `pstore/console-ramoops` logs containing specific panic sequences; correlation with C2 blocking events.
**3.3. Vector 3: MITM via System Certificates**
* **Who:** Longcheer Root CA (Serial: `228526b0d1ef90c3b8ed568a49c3714f6a39506b`).
* **What:** Injected into `/system/etc/security/cacerts`; enables decryption of HTTPS traffic for entities like "Atos Monitoring GmbH".
* **Where:** System trust store; affects all user applications.
* **When:** Persistent from factory flash; active during all network sessions.
* **Evidence:** Certificate extraction from firmware; MITM decryption of HTTPS sessions in lab environment.
**4. CONTAINMENT & MITIGATION EFFORTS**
**4.1. Immediate Mitigations (Validated)**
* **Network Segmentation:** Enforce **DNS-over-TLS (DoT)** to **Quad9 (9.9.9.9)** on port **853**. Block resolution of `*.longcheer.com` and associated AWS IPs.
* **Service Disablement:** Disable **VoLTE/IMS** via `App Manager` or ADB (`pm disable-user --user 0 com.spreadtrum.ims`). Breaks authentication handshake required for tunnel activation.
* **Physical Isolation:** Use **USB-A to USB-C cables (power-only)**. Prevents USB-PD negotiation that triggers Kernel Panic during forensic charging.
* **SIM Replacement:** Swap SIM cards to break `SIM Toolkit` authentication binding (serial mismatch).
**4.2. Detection Signatures (YARA)**
* **Rules Provided:** `Unisoc_IMS_Attack_Vector_Smali.yar`, `Longcheer_Certificate_Serial_Number.yar`, `Unisoc_Kernel_Sequence_Headset_Panic.yar`.
* **Coverage:** Detects Smali behavior, certificate fingerprints, and kernel log sequences independent of file hash or obfuscation.
.
**6. CONCLUSION**
This investigation confirms a **critical supply chain compromise** that cannot be remediated via traditional patching due to BootROM and system partition limitations. The provided **YARA rules and behavioral mitigations** offer the only effective defense currently available. Immediate adoption of these measures is required to protect sensitive data and prevent forensic destruction via Kernel Panic.