Analysis of NCHGBIOS2x64.SYS: vulnerable verdict, risk score 72/100. 3 YARA matches, 1/75 multi-engine detections. SHA256 314384b40626800b. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.
DriverShield analyzed the Windows kernel driver NCHGBIOS2x64.SYS and assigned a verdict of Vulnerable with a composite risk score of 72/100, indicating a known or likely vulnerability surface (60-79 band).
| Verdict | Vulnerable (72/100) |
| YARA matches | 3 |
| Multi-engine detections | 1 / 75 |
| File size | 18840 bytes |
| Code-signing signer | Symantec Time Stamping Services CA - G2 |
| Analyzed | 2026-09-06 |
| SHA256 | 314384b40626800b1cde6fbc51ebc7d13e91398be2688c2a58354aa08d00b073 |
| SHA1 | d0d39e1061f30946141b6ecfa0957f8cc3ddeb63 |
| MD5 | d9ce18960c23f38706ae9c6584d9ac90 |
Version resource data embedded in the NCHGBIOS2x64.SYS PE header, as extracted by the analysis engine.
| File description | BIOS Update Driver For Windows x64 Edition |
|---|---|
| Product | TOSHIBA BIOS Package |
| Company | TOSHIBA Corporation |
| Original filename | NCHGBIOS2x64.SYS |
| Internal name | NCHGBIOS2x64.SYS |
| File version | 4.2.4.0 built by: WinDDK |
| Copyright | Copyright (C) 1999-2012 TOSHIBA Corporation. All Rights Reserved. |
Each component is scored 0-100 and then weighted into the composite. See the analysis methodology for the exact formula.
| Component | Sub-score |
|---|---|
| Multi-engine consensus | 0 / 100 |
| YARA signature matches | 85 / 100 |
| Dangerous kernel imports | 100 / 100 |
| IOCTL dispatch surface | 9 / 100 |
| Known-vulnerable corpus | 100 / 100 |
| Code-signing state | 80 / 100 |
| Packing and entropy | 0 / 100 |
| Dynamic behaviour | 0 / 100 |
| CVE cross-reference | 0 / 100 |
Kernel-mode APIs resolved from the Import Address Table of NCHGBIOS2x64.SYS, ranked by exploitation relevance.
| API | Risk | Why it matters |
|---|---|---|
| MmMapIoSpace | critical | Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination |
| MmMapLockedPagesSpecifyCache | critical | Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination |
| MmGetPhysicalAddress | high | Potentially dangerous - could be used for privilege escalation or security bypass |
| HalGetBusDataByOffset | high | Potentially dangerous - could be used for privilege escalation or security bypass |
| HalSetBusDataByOffset | high | Potentially dangerous - could be used for privilege escalation or security bypass |
| MmAllocateContiguousMemory | high | Potentially dangerous - could be used for privilege escalation or security bypass |
| KeBugCheckEx | medium | Moderate risk - system modification capability |
| MmUnmapIoSpace | medium | Moderate risk - system modification capability |
| IofCompleteRequest | low | Standard kernel API - generally benign |
| IoCreateDevice | low | Standard kernel API - generally benign |
| IoCreateSymbolicLink | low | Standard kernel API - generally benign |
| IoDeleteSymbolicLink | low | Standard kernel API - generally benign |
| IoDeleteDevice | low | Standard kernel API - generally benign |
| RtlInitUnicodeString | low | Standard kernel API - generally benign |
Control codes reachable through the driver dispatch routine. Codes tied to published exploit code are flagged, since they are the primary Bring Your Own Vulnerable Driver (BYOVD) entry points.
| Code | Severity | Transfer | Description |
|---|---|---|---|
| 0x002200F0 | medium | METHOD_BUFFERED | FILE_DEVICE_UNKNOWN Function #60 |
| 0x003403B0 | medium | METHOD_BUFFERED | FILE_DEVICE_DISK Function #236 |
| 0x00340036 | medium | METHOD_OUT_DIRECT | FILE_DEVICE_DISK Function #13 |
Section layout and Shannon entropy. High entropy in a code section is a packing or encryption indicator.
| Section | Virtual size | Raw size | Entropy | Flags |
|---|---|---|---|---|
| .text | 0x110C | 0x1200 | 5.99 | CODE, EXEC, READ |
| .rdata | 0x01A8 | 0x0200 | 4.11 | IDATA, READ |
| .data | 0x0118 | 0x0200 | 0.3 | IDATA, READ, WRITE |
| .pdata | 0x006C | 0x0200 | 0.96 | IDATA, READ |
| INIT | 0x02AE | 0x0400 | 3.68 | CODE, EXEC, READ, WRITE, DISCARD |
| .rsrc | 0x0410 | 0x0600 | 2.53 | IDATA, READ, DISCARD |
| Control Flow Guard | Not enabled |
|---|---|
| ASLR | Not enabled |
| DEP | Not enabled |
| Integrity check | Not enforced |
| Mitigation score | 5 / 100 |
| Rule | Severity | Detects |
|---|---|---|
| PUA_VULN_Driver_Toshibacorporation_Nchgbiosxsys_Toshibabiospackage_3143 | medium | Detects vulnerable driver mentioned in known-vulnerable driver corpus project using VersionInfo values from the PE header - NCHGBIOS2x64.SYS. Investigate matches in context: expected filenames or stan... |
| BYOVD_MemRW | critical | Phys memory mapping + device creation |
| SUSP_PhysMem | high | Physical memory mapping |
Techniques this driver could enable if loaded by an adversary.
| ID | Technique | Tactic |
|---|---|---|
| T1003 | OS Credential Dumping | Credential Access |
| T1003.001 | OS Credential Dumping: LSASS Memory | Credential Access |
| T1006 | Direct Volume Access | Defense Evasion |
| T1014 | Rootkit | Defense Evasion |
| T1055.012 | Process Hollowing | Defense Evasion |
| T1068 | Exploitation for Privilege Escalation | Privilege Escalation |
| T1071 | Application Layer Protocol | Command and Control |
| T1542.001 | Pre-OS Boot: System Firmware | Persistence |
| T1543.003 | Windows Service | Persistence |
| T1562.001 | Impair Defenses | Defense Evasion |
| T1569.002 | Service Execution | Execution |
| T1601 | Modify System Image | Defense Evasion |
| T1652 | Device Driver Discovery | Discovery |
| Signer | Symantec Time Stamping Services CA - G2 |
|---|---|
| Signer organisation | Symantec Corporation |
| Issuer | Thawte Timestamping CA |
| Serial | 7E93EBFB7CC64E59EA4B9A77D406FC3B |
| Valid from | 2012-12-21 00:00 UTC |
| Valid until | 2020-12-30 23:59 UTC (expired) |
| Signature validity | Not verified |
Engine angr, status completed, 17 paths explored at a maximum depth of 17. Vulnerability classes reached: 1. Exploitable paths: 0.
Corpus match: this hash is present in the known-vulnerable driver corpus DriverShield cross-references during analysis, which is why the score carries a full weighting on that component.
Based on DriverShield static and dynamic analysis, NCHGBIOS2x64.SYS is flagged as vulnerable and is a potential Bring Your Own Vulnerable Driver (BYOVD) risk. Its composite risk score is 72/100 (verdict: vulnerable). Always validate findings independently before acting.
NCHGBIOS2x64.SYS has a DriverShield composite risk score of 72/100, placing it in the vulnerable verdict band. SHA256: 314384b40626800b1cde6fbc51ebc7d13e91398be2688c2a58354aa08d00b073.
NCHGBIOS2x64.SYS is a Windows kernel-mode driver (.sys) analyzed by DriverShield for vulnerabilities, BYOVD abuse potential, and malware indicators. It is code-signed by Symantec Time Stamping Services CA - G2.
Related: Other drivers signed by Symantec Time Stamping Services CA - G2 · What an IOCTL dispatch code is · How YARA matching feeds the score · BYOVD research index · full driver database · CVE library · code signing atlas