cpuz.sys - Vulnerable (72/100) - DriverShield Analysis

Analysis of cpuz.sys: vulnerable verdict, risk score 72/100. 4 YARA matches, 1/75 multi-engine detections. SHA256 8c95d28270a4a314. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.

cpuz.sys - Analysis Report

DriverShield analyzed the Windows kernel driver cpuz.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	4
Multi-engine detections	1 / 75
File size	21992 bytes
Code-signing signer	VeriSign Time Stamping Services Signer - G2
Analyzed	2026-09-06
SHA256	8c95d28270a4a314299cf50f05dcbe63033b2a555195d2ad2f678e09e00393e6
SHA1	4d41248078181c7f61e6e4906aa96bbdea320dc2
MD5	c2eb4539a4f6ab6edd01bdc191619975

Driver identity

Version resource data embedded in the cpuz.sys PE header, as extracted by the analysis engine.

File description	CPUID Driver
Product	CPUID service
Company	CPUID
Original filename	cpuz.sys
Internal name	cpuz.sys
File version	6.1.7600.16385 built by: WinDDK
Copyright	Copyright(C) 2010 CPUID

How the 72/100 score breaks down

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	90 / 100
Dangerous kernel imports	100 / 100
IOCTL dispatch surface	6 / 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 imports (22)

Kernel-mode APIs resolved from the Import Address Table of cpuz.sys, ranked by exploitation relevance.

API	Risk	Why it matters
MmMapIoSpace	critical	Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination
HalSetBusDataByOffset	high	Potentially dangerous - could be used for privilege escalation or security bypass
READ_PORT_UCHAR	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
WRITE_PORT_UCHAR	high	Potentially dangerous - could be used for privilege escalation or security bypass
WRITE_PORT_ULONG	high	Potentially dangerous - could be used for privilege escalation or security bypass
READ_PORT_ULONG	high	Potentially dangerous - could be used for privilege escalation or security bypass
MmUnmapIoSpace	medium	Moderate risk - system modification capability
KeBugCheckEx	medium	Moderate risk - system modification capability
IoGetDeviceObjectPointer	medium	Moderate risk - system modification capability
IoCreateSymbolicLink	low	Standard kernel API - generally benign
IoDeleteSymbolicLink	low	Standard kernel API - generally benign
IoCreateDevice	low	Standard kernel API - generally benign
IoDeleteDevice	low	Standard kernel API - generally benign
ExAllocatePoolWithTag	low	Standard kernel API - generally benign
ExFreePool	low	Standard kernel API - generally benign
RtlInitUnicodeString	low	Standard kernel API - generally benign
IoBuildDeviceIoControlRequest	low	Standard kernel API - generally benign
IofCompleteRequest	low	Standard kernel API - generally benign
RtlInitAnsiString	low	Standard kernel API - generally benign
KeWaitForSingleObject	low	Standard kernel API - generally benign
KeInitializeEvent	low	Standard kernel API - generally benign

IOCTL dispatch codes (2)

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
0x008083C7	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #241
0x003402F0	medium	METHOD_BUFFERED	FILE_DEVICE_DISK Function #188

PE sections

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	0x25F0	0x2600	6.2	CODE, EXEC, READ
.rdata	0x0300	0x0400	3.66	IDATA, READ
.data	0x01E0	0x0200	0.32	IDATA, READ, WRITE
INIT	0x03F4	0x0400	5.38	CODE, EXEC, READ, WRITE, DISCARD
.rsrc	0x0350	0x0400	2.93	IDATA, READ, DISCARD
.reloc	0x024C	0x0400	3.69	IDATA, READ, DISCARD

Exploit mitigations

Control Flow Guard	Not enabled
ASLR	Not enabled
DEP	Not enabled
Integrity check	Not enforced
Mitigation score	5 / 100

• No CFG - Control Flow Guard is not enabled. Indirect call targets are not validated, making the driver susceptible to control flow hijacking via corrupted function pointers or vtables.
• No ASLR - ASLR is disabled. The driver loads at a predictable address, enabling reliable exploitation of memory corruption vulnerabilities.
• No DEP - DEP is disabled. Data pages are executable, allowing shellcode execution from stack/heap buffers.
• Expired Certificate - The driver is signed but the certificate has expired. Windows may still load it depending on revocation policy.

YARA rule matches (4)

Rule	Severity	Detects
PUA_VULN_Driver_Cpuid_Cpuzsys_Cpuidservice_0D37	medium	Detects vulnerable driver mentioned in known-vulnerable driver corpus project using VersionInfo values from the PE header - cpuz.sys. Investigate matches in context: expected filenames or standard ven...
BYOVD_MemRW	critical	Phys memory mapping + device creation
SUSP_PhysMem	high	Physical memory mapping
SUSP_PortIO	medium	Direct port I/O

MITRE ATT&CK techniques (15)

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
T1211	Exploitation for Defense Evasion	Defense Evasion
T1542.001	Pre-OS Boot: System Firmware	Persistence
T1543.003	Windows Service	Persistence
T1553.002	Subvert Trust Controls: Code Signing	Defense Evasion
T1562.001	Impair Defenses	Defense Evasion
T1569.002	Service Execution	Execution
T1601	Modify System Image	Defense Evasion
T1652	Device Driver Discovery	Discovery

Code-signing chain

Signer	VeriSign Time Stamping Services Signer - G2
Signer organisation	VeriSign, Inc.
Issuer	VeriSign Time Stamping Services CA
Serial	3825D7FAF861AF9EF490E726B5D65AD5
Valid from	2007-06-15 00:00 UTC
Valid until	2012-06-14 23:59 UTC (expired)
Signature validity	Not verified

• Certificate revision: 0x0200
• Certificate type: PKCS#7
• Chain: VeriSign Time Stamping Services CA
• Chain: VeriSign Class 3 Code Signing 2004 CA
• Chain: CPUID

Symbolic execution

Engine angr, status completed, 4 paths explored at a maximum depth of 4. Vulnerability classes reached: 0. 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.

Frequently asked questions about cpuz.sys

Is cpuz.sys safe?

Based on DriverShield static and dynamic analysis, cpuz.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.

What is the risk score of cpuz.sys?

cpuz.sys has a DriverShield composite risk score of 72/100, placing it in the vulnerable verdict band. SHA256: 8c95d28270a4a314299cf50f05dcbe63033b2a555195d2ad2f678e09e00393e6.

What is cpuz.sys?

cpuz.sys is a Windows kernel-mode driver (.sys) analyzed by DriverShield for vulnerabilities, BYOVD abuse potential, and malware indicators. It is code-signed by VeriSign Time Stamping Services Signer - G2.

Related: Other drivers signed by VeriSign Time Stamping Services Signer - G2 · What an IOCTL dispatch code is · How YARA matching feeds the score · BYOVD research index · full driver database · CVE library · code signing atlas

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