netbios.sys - Clean (25/100) - DriverShield Analysis

Analysis of netbios.sys: clean verdict, risk score 25/100. 0 YARA matches. SHA256 e7f7f30d9513fdd2. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.

netbios.sys - Analysis Report

DriverShield analyzed the Windows kernel driver netbios.sys and assigned a verdict of Clean with a composite risk score of 25/100, indicating no notable risk signals (0-29 band).

VerdictClean (25/100)
YARA matches0
File size64312 bytes
Code-signing signerMicrosoft Windows
Analyzed2026-03-22
SHA256e7f7f30d9513fdd2236fcfd5549dcd93101562ba1117213ea4df32b70bb48a73
SHA1af22e35fd3a1d8de52a6f7b2ffcf64a16ca28357
MD54687fac962855bdb1896c02334e95d54

Driver identity

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

File descriptionNetBIOS interface driver
ProductMicrosoft® Windows® Operating System
CompanyMicrosoft Corporation
Original filenameNETBIOS.SYS
Internal nameNETBIOS.SYS
File version10.0.19041.1 (WinBuild.160101.0800)
Copyright© Microsoft Corporation. All rights reserved.

How the 25/100 score breaks down

Each component is scored 0-100 and then weighted into the composite. See the analysis methodology for the exact formula.

ComponentSub-score
Multi-engine consensus0 / 100
YARA signature matches0 / 100
Dangerous kernel imports100 / 100
IOCTL dispatch surface24 / 100
Known-vulnerable corpus0 / 100
Code-signing state80 / 100
Packing and entropy0 / 100
Dynamic behaviour0 / 100
CVE cross-reference0 / 100

Kernel imports (18)

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

APIRiskWhy it matters
MmMapLockedPagesSpecifyCachecriticalHighly dangerous - potential for arbitrary code execution, memory corruption, or process termination
ObReferenceObjectByHandlemediumModerate risk - system modification capability
ZwCreateKeymediumModerate risk - system modification capability
KeWaitForSingleObjectlowStandard kernel API - generally benign
ZwCreateFilelowStandard kernel API - generally benign
KeSetEventlowStandard kernel API - generally benign
KeInitializeEventlowStandard kernel API - generally benign
RtlInitUnicodeStringlowStandard kernel API - generally benign
ZwCloselowStandard kernel API - generally benign
ExAllocatePoolWithTaglowStandard kernel API - generally benign
IoDeleteDevicelowStandard kernel API - generally benign
IoCreateDevicelowStandard kernel API - generally benign
ZwQueryValueKeylowStandard kernel API - generally benign
IofCompleteRequestlowStandard kernel API - generally benign
IoBuildDeviceIoControlRequestlowStandard kernel API - generally benign
ProbeForWritelowStandard kernel API - generally benign
ZwOpenKeylowStandard kernel API - generally benign
ProbeForReadlowStandard kernel API - generally benign

IOCTL dispatch codes (8)

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.

CodeSeverityTransferDescription
0x0080838BhighMETHOD_NEITHERFILE_DEVICE_CUSTOM Function #226
0x0080A383highMETHOD_NEITHERFILE_DEVICE_CUSTOM Function #2272
0x002200F0mediumMETHOD_BUFFEREDFILE_DEVICE_UNKNOWN Function #60
0x00342464mediumMETHOD_BUFFEREDFILE_DEVICE_DISK Function #2329
0x00809589mediumMETHOD_IN_DIRECTFILE_DEVICE_CUSTOM Function #1378
0x00220112mediumMETHOD_OUT_DIRECTFILE_DEVICE_UNKNOWN Function #68
0x00802824mediumMETHOD_BUFFEREDFILE_DEVICE_CUSTOM Function #2569
0x00340390mediumMETHOD_BUFFEREDFILE_DEVICE_DISK Function #228

PE sections

Section layout and Shannon entropy. High entropy in a code section is a packing or encryption indicator.

SectionVirtual sizeRaw sizeEntropyFlags
.text0x56E80x58006.09CODE, EXEC, READ
.rdata0x0C000x0C004.97IDATA, READ
.data0x03F80x02001.69IDATA, READ, WRITE
.pdata0x05580x06004.11IDATA, READ
.idata0x09000x0A004.21IDATA, READ
PAGE0x44C00x46006.08CODE, EXEC, READ
INIT0x05240x06005.21CODE, EXEC, READ, DISCARD
GFIDS0x00540x02000.78IDATA, READ, DISCARD
.rsrc0x05E00x06003.24IDATA, READ, DISCARD
.reloc0x0B800x0C005.5IDATA, READ, DISCARD

Exploit mitigations

Control Flow GuardEnabled
ASLREnabled
DEPEnabled
Integrity checkNot enforced
Mitigation score85 / 100

MITRE ATT&CK techniques (12)

Techniques this driver could enable if loaded by an adversary.

IDTechniqueTactic
T1003.001OS Credential Dumping: LSASS MemoryCredential Access
T1055.001Process Injection: DLL InjectionDefense Evasion
T1055.012Process HollowingDefense Evasion
T1068Exploitation for Privilege EscalationPrivilege Escalation
T1071Application Layer ProtocolCommand and Control
T1211Exploitation for Defense EvasionDefense Evasion
T1489Service StopImpact
T1543.003Windows ServicePersistence
T1553.002Subvert Trust Controls: Code SigningDefense Evasion
T1562.001Impair Defenses: Disable/Modify ToolsDefense Evasion
T1569.002Service ExecutionExecution
T1652Device Driver DiscoveryDiscovery

Code-signing chain

SignerMicrosoft Windows
Signer organisationMicrosoft Corporation
IssuerMicrosoft Windows Production PCA 2011
Serial330000023241FB59996DCC4DFF000000000232
Valid from2019-05-02 21:24 UTC
Valid until2020-05-02 21:24 UTC (expired)
Signature validityNot verified

Symbolic execution

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

Frequently asked questions about netbios.sys

Is netbios.sys safe?

Based on DriverShield static and dynamic analysis, netbios.sys is assessed as clean, with no notable risk signals. Its composite risk score is 25/100 (verdict: clean). Always validate findings independently before acting.

What is the risk score of netbios.sys?

netbios.sys has a DriverShield composite risk score of 25/100, placing it in the clean verdict band. SHA256: e7f7f30d9513fdd2236fcfd5549dcd93101562ba1117213ea4df32b70bb48a73.

What is netbios.sys?

netbios.sys is a Windows kernel-mode driver (.sys) analyzed by DriverShield for vulnerabilities, BYOVD abuse potential, and malware indicators. It is code-signed by Microsoft Windows.

Related: Other drivers signed by Microsoft Windows · What an IOCTL dispatch code is · BYOVD research index · full driver database · CVE library · code signing atlas


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