win32kbase.sys - Suspicious (58/100) - DriverShield Analysis

Analysis of win32kbase.sys: suspicious verdict, risk score 58/100. 0 YARA matches, 0/76 multi-engine detections. SHA256 c8d97abb67e3b0e7. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.

win32kbase.sys - Analysis Report

DriverShield analyzed the Windows kernel driver win32kbase.sys and assigned a verdict of Suspicious with a composite risk score of 58/100, indicating some risk signals warranting review (30-59 band).

Verdict	Suspicious (58/100)
YARA matches	0
Multi-engine detections	0 / 76
File size	2911744 bytes
Analyzed	2026-03-23
SHA256	c8d97abb67e3b0e7ce206e4d2fd6e7a1997e48ba1ef5f567ce1545ab7ac21045
SHA1	3a9a553e726788076a7edf68db56c51b1859814d
MD5	bd60b877337f77c49cbfe4f60b6dda94

Driver identity

Version resource data embedded in the win32kbase.sys PE header, as extracted by the analysis engine.

File description	Base Win32k Kernel Driver
Product	Microsoft® Windows® Operating System
Company	Microsoft Corporation
Original filename	win32kbase.sys
Internal name	win32kbase.sys
File version	10.0.19041.6456 (WinBuild.160101.0800)
Copyright	© Microsoft Corporation. All rights reserved.

How the 58/100 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	0 / 100
Dangerous kernel imports	100 / 100
IOCTL dispatch surface	100 / 100
Known-vulnerable corpus	0 / 100
Code-signing state	50 / 100
Packing and entropy	0 / 100
Dynamic behaviour	0 / 100
CVE cross-reference	0 / 100

Kernel imports (33)

Kernel-mode APIs resolved from the Import Address Table of win32kbase.sys, ranked by exploitation relevance.

API	Risk	Why it matters
ZwTerminateProcess	critical	Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination
ZwMapViewOfSection	critical	Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination
KeAttachProcess	high	Potentially dangerous - could be used for privilege escalation or security bypass
PsLookupProcessByProcessId	high	Potentially dangerous - could be used for privilege escalation or security bypass
ZwSetSystemInformation	high	Potentially dangerous - could be used for privilege escalation or security bypass
ZwOpenProcess	high	Potentially dangerous - could be used for privilege escalation or security bypass
MmGetSystemRoutineAddress	high	Potentially dangerous - could be used for privilege escalation or security bypass
ZwQuerySystemInformation	medium	Moderate risk - system modification capability
IoGetDeviceObjectPointer	medium	Moderate risk - system modification capability
ZwCreateKey	medium	Moderate risk - system modification capability
ObReferenceObjectByHandle	medium	Moderate risk - system modification capability
ObOpenObjectByPointer	medium	Moderate risk - system modification capability
KeBugCheckEx	medium	Moderate risk - system modification capability
ZwSetValueKey	medium	Moderate risk - system modification capability
RtlInitAnsiString	low	Standard kernel API - generally benign
ZwCreateFile	low	Standard kernel API - generally benign
ZwQueryInformationFile	low	Standard kernel API - generally benign
ZwClose	low	Standard kernel API - generally benign
KeSetEvent	low	Standard kernel API - generally benign
IoBuildDeviceIoControlRequest	low	Standard kernel API - generally benign
ZwReadFile	low	Standard kernel API - generally benign
DbgPrint	low	Standard kernel API - generally benign
RtlInitUnicodeString	low	Standard kernel API - generally benign
KeDelayExecutionThread	low	Standard kernel API - generally benign
KeWaitForSingleObject	low	Standard kernel API - generally benign
ProbeForWrite	low	Standard kernel API - generally benign
ZwOpenFile	low	Standard kernel API - generally benign
PsGetCurrentProcess	low	Standard kernel API - generally benign

Showing the 28 highest-relevance imports of 33 resolved.

IOCTL dispatch codes (40)

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
0x0080B9FF	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #3711
0x0080A383	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #2272
0x0080898B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #610
0x0080840F	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #259
0x0080808B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #34
0x0080BF8B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #4066
0x0080B68B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #3490
0x00220D07	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #833
0x00224A63	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #664
0x0080888B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #546
0xC350C043	high	METHOD_NEITHER	CUSTOM_MSI Function #16
0x00808A03	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #640
0x0080850F	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #323
0x0080880F	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #515
0x00808D0F	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #835
0x00808D8B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #866
0x0022E80B	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #2562
0x00806583	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #2400
0x0080A783	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #2528
0x0022B9DB	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #3702
0x003407C7	high	METHOD_NEITHER	FILE_DEVICE_DISK Function #497
0x0022E8CF	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #2611
0x0080B18B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #3170
0x00809E3B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #1934

Showing 24 of 40 extracted control codes.

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	0x1FFDED	0x1FFE00	6.4	CODE, EXEC, READ
.rdata	0x43DA8	0x43E00	5.57	IDATA, READ
.data	0x136BC	0x9C00	2.9	IDATA, READ, WRITE
.pdata	0x1CECC	0x1D000	6.25	IDATA, READ
.idata	0x52B2	0x5400	5.08	IDATA, READ
.kbdfall	0x0900	0x0A00	3.41	IDATA, READ, WRITE
NONPAGE	0x00B0	0x0200	0.27	IDATA, READ, WRITE
PAGE	0x184D	0x1A00	5.96	CODE, EXEC, READ
.edata	0x16F11	0x17000	6.16	IDATA, READ
INIT	0x46F4	0x4800	6.3	CODE, EXEC, READ, DISCARD
GFIDS	0x3EE0	0x4000	5.13	IDATA, READ, DISCARD
.rsrc	0x245B0	0x24600	3.94	IDATA, READ, DISCARD
.reloc	0x1085C	0x10A00	6.47	IDATA, READ, DISCARD

Exploit mitigations

Control Flow Guard	Enabled
ASLR	Enabled
DEP	Enabled
Integrity check	Not enforced
Mitigation score	80 / 100

CFG Enabled - Control Flow Guard is active - indirect calls are validated against a bitmap of valid targets at runtime.
ASLR Enabled - Address Space Layout Randomization is active - base address is randomized on each load.
DEP/NX Enabled - Data Execution Prevention is active - non-executable pages cannot be executed.
Unsigned - The driver is not digitally signed. It requires test signing mode or a bootloader exploit to load on 64-bit Windows.

MITRE ATT&CK techniques (14)

Techniques this driver could enable if loaded by an adversary.

ID	Technique	Tactic
T1003.001	OS Credential Dumping: LSASS Memory	Credential Access
T1055.001	Process Injection: DLL Injection	Defense Evasion
T1055.012	Process Hollowing	Defense Evasion
T1068	Exploitation for Privilege Escalation	Privilege Escalation
T1112	Modify Registry	Defense Evasion
T1211	Exploitation for Defense Evasion	Defense Evasion
T1489	Service Stop	Impact
T1543.003	Windows Service	Persistence
T1547.001	Registry Run Keys	Persistence
T1553.002	Subvert Trust Controls: Code Signing	Defense Evasion
T1553.006	Code Signing Policy Modification	Defense Evasion
T1562.001	Disable/Modify Tools	Defense Evasion
T1569.002	Service Execution	Execution
T1652	Device Driver Discovery	Discovery

Symbolic execution

Engine angr, status completed, 8 paths explored at a maximum depth of 8. Vulnerability classes reached: 0. Exploitable paths: 0.

Frequently asked questions about win32kbase.sys

Is win32kbase.sys safe?

Based on DriverShield static and dynamic analysis, win32kbase.sys shows some suspicious signals and warrants manual review. Its composite risk score is 58/100 (verdict: suspicious). Always validate findings independently before acting.

What is the risk score of win32kbase.sys?

win32kbase.sys has a DriverShield composite risk score of 58/100, placing it in the suspicious verdict band. SHA256: c8d97abb67e3b0e7ce206e4d2fd6e7a1997e48ba1ef5f567ce1545ab7ac21045.

What is win32kbase.sys?

win32kbase.sys is a Windows kernel-mode driver (.sys) analyzed by DriverShield for vulnerabilities, BYOVD abuse potential, and malware indicators.