iorate.sys - Clean (26/100) - DriverShield Analysis

Analysis of iorate.sys: clean verdict, risk score 26/100. 1 YARA match. SHA256 d3c4d8103aa33dfb. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.

iorate.sys - Analysis Report

DriverShield analyzed the Windows kernel driver iorate.sys and assigned a verdict of Clean with a composite risk score of 26/100, indicating no notable risk signals (0-29 band).

Verdict	Clean (26/100)
YARA matches	1
File size	58328 bytes
Code-signing signer	Microsoft Windows
Analyzed	2026-03-22
SHA256	d3c4d8103aa33dfbbb76afcda0e8d8c4e0d12d241f6b5e3ae88159c0abd1f445
SHA1	380b5196af4d997026184cd3ee6fe6b74fee7005
MD5	2783563d0ee1eb526c7fa5424f2705a5

Driver identity

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

File description	I/O rate control Filter
Product	Microsoft® Windows® Operating System
Company	Microsoft Corporation
Original filename	iorate.sys
Internal name	iorate.sys
File version	10.0.19041.3636 (WinBuild.160101.0800)
Copyright	© Microsoft Corporation. All rights reserved.

How the 26/100 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	5 / 100
Dangerous kernel imports	81 / 100
IOCTL dispatch surface	51 / 100
Known-vulnerable corpus	0 / 100
Code-signing state	80 / 100
Packing and entropy	0 / 100
Dynamic behaviour	0 / 100
CVE cross-reference	0 / 100

Kernel imports (13)

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

API	Risk	Why it matters
PsSetCreateProcessNotifyRoutineEx	high	Potentially dangerous - could be used for privilege escalation or security bypass
ObReferenceObjectByHandle	medium	Moderate risk - system modification capability
IoDeleteDevice	low	Standard kernel API - generally benign
IofCompleteRequest	low	Standard kernel API - generally benign
KeWaitForSingleObject	low	Standard kernel API - generally benign
IoCreateDevice	low	Standard kernel API - generally benign
ZwQueryValueKey	low	Standard kernel API - generally benign
ExAllocatePoolWithTag	low	Standard kernel API - generally benign
ZwOpenKey	low	Standard kernel API - generally benign
KeInitializeEvent	low	Standard kernel API - generally benign
IoBuildDeviceIoControlRequest	low	Standard kernel API - generally benign
ZwClose	low	Standard kernel API - generally benign
RtlInitUnicodeString	low	Standard kernel API - generally benign

IOCTL dispatch codes (17)

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
0x0080B983	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #3680
0x00220117	high	METHOD_NEITHER	FILE_DEVICE_UNKNOWN Function #69
0x002200F0	medium	METHOD_BUFFERED	FILE_DEVICE_UNKNOWN Function #60
0x0080249C	medium	METHOD_BUFFERED	FILE_DEVICE_CUSTOM Function #2343
0x008081C1	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #112
0x00220022	medium	METHOD_OUT_DIRECT	FILE_DEVICE_UNKNOWN Function #8
0x00800026	medium	METHOD_OUT_DIRECT	FILE_DEVICE_CUSTOM Function #9
0x00800028	medium	METHOD_BUFFERED	FILE_DEVICE_CUSTOM Function #10
0x00800049	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #18
0x0022641E	medium	METHOD_OUT_DIRECT	FILE_DEVICE_UNKNOWN Function #2311
0x00802494	medium	METHOD_BUFFERED	FILE_DEVICE_CUSTOM Function #2341
0x00228341	medium	METHOD_IN_DIRECT	FILE_DEVICE_UNKNOWN Function #208
0xC3504089	medium	METHOD_IN_DIRECT	CUSTOM_MSI Function #34
0x00228348	medium	METHOD_BUFFERED	FILE_DEVICE_UNKNOWN Function #210
0x0080C481	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #288
0x0034BB0A	medium	METHOD_OUT_DIRECT	FILE_DEVICE_DISK Function #3778
0x00340398	medium	METHOD_BUFFERED	FILE_DEVICE_DISK Function #230

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	0x60A9	0x6200	6.04	CODE, EXEC, READ
.rdata	0x1850	0x1A00	4.86	IDATA, READ
.data	0x0780	0x0200	0.36	IDATA, READ, WRITE
.pdata	0x048C	0x0600	3.55	IDATA, READ
.idata	0x0CE8	0x0E00	4.45	IDATA, READ
PAGE	0x0A79	0x0C00	5.62	CODE, EXEC, READ
INIT	0x0A02	0x0C00	5.4	CODE, EXEC, READ, DISCARD
GFIDS	0x005C	0x0200	0.82	IDATA, READ, DISCARD
.rsrc	0x0608	0x0800	2.66	IDATA, READ, DISCARD
.reloc	0x04B4	0x0600	4.65	IDATA, READ, DISCARD

Exploit mitigations

Control Flow Guard	Enabled
ASLR	Enabled
DEP	Enabled
Integrity check	Enforced
Mitigation score	90 / 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.
• Expired Certificate - The driver is signed but the certificate has expired. Windows may still load it depending on revocation policy.
• Force Integrity - IMAGE_DLLCHARACTERISTICS_FORCE_INTEGRITY is set - the OS validates the signature before loading.

YARA rule matches (1)

Rule	Severity	Detects
SUSP_Callbacks	medium	Kernel callback registration

MITRE ATT&CK techniques (11)

Techniques this driver could enable if loaded by an adversary.

ID	Technique	Tactic
T1014	Rootkit	Defense Evasion
T1071	Application Layer Protocol	Command and Control
T1112	Modify Registry	Defense Evasion
T1211	Exploitation for Defense Evasion	Defense Evasion
T1543.003	Windows Service	Persistence
T1547.001	Registry Run Keys	Persistence
T1553.002	Subvert Trust Controls: Code Signing	Defense Evasion
T1562.006	Indicator Blocking	Defense Evasion
T1564.001	Hidden Files and Directories	Defense Evasion
T1569.002	System Services: Service Execution	Execution
T1652	Device Driver Discovery	Discovery

Code-signing chain

Signer	Microsoft Windows
Signer organisation	Microsoft Corporation
Issuer	Microsoft Windows Production PCA 2011
Serial	33000004158295A1A3D82E2857000000000415
Valid from	2023-02-03 00:05 UTC
Valid until	2024-02-01 00:05 UTC (expired)
Signature validity	Not verified

• Certificate revision: 0x0200
• Certificate type: PKCS#7
• Chain: Microsoft Windows Production PCA 2011

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 iorate.sys

Is iorate.sys safe?

Based on DriverShield static and dynamic analysis, iorate.sys is assessed as clean, with no notable risk signals. Its composite risk score is 26/100 (verdict: clean). Always validate findings independently before acting.

What is the risk score of iorate.sys?

iorate.sys has a DriverShield composite risk score of 26/100, placing it in the clean verdict band. SHA256: d3c4d8103aa33dfbbb76afcda0e8d8c4e0d12d241f6b5e3ae88159c0abd1f445.

What is iorate.sys?

iorate.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 · How YARA matching feeds the score · BYOVD research index · full driver database · CVE library · code signing atlas

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