silabser.sys - Clean (14/100) - DriverShield Analysis

Analysis of silabser.sys: clean verdict, risk score 14/100. 0 YARA matches, 0/75 multi-engine detections. SHA256 d1a4b2fa462dbdfe. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.

silabser.sys - Analysis Report

DriverShield analyzed the Windows kernel driver silabser.sys and assigned a verdict of Clean with a composite risk score of 14/100, indicating no notable risk signals (0-29 band).

Verdict	Clean (14/100)
YARA matches	0
Multi-engine detections	0 / 75
File size	97160 bytes
Code-signing signer	Silicon Laboratories Inc.
Analyzed	2026-05-01
SHA256	d1a4b2fa462dbdfed7e263df79e9f96f779eebc1026cd4d8e1c1bb31f48eeb69
SHA1	f8359676e7797238a2325f7a45467b1c98a35119
MD5	0586bf25ce29189803e377610a15c4a5

Driver identity

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

File description	Silicon Labs CP210x USB to UART Bridge Driver (64-bit)
Product	Silicon Labs USBXpress Software
Company	Silicon Laboratories Inc.
Original filename	silabser.sys
Internal name	silabser
File version	6.7.6.2130
Copyright	Copyright © 2018 Silicon Laboratories Inc., All Rights Reserved.

How the 14/100 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	15 / 100
IOCTL dispatch surface	54 / 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 (5)

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

API	Risk	Why it matters
KeBugCheckEx	medium	Moderate risk - system modification capability
ExAllocatePoolWithTag	low	Standard kernel API - generally benign
RtlInitUnicodeString	low	Standard kernel API - generally benign
KeDelayExecutionThread	low	Standard kernel API - generally benign
IofCompleteRequest	low	Standard kernel API - generally benign

IOCTL dispatch codes (18)

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
0x0080978B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #1506
0x0080938B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #1250
0x0080968B	high	METHOD_NEITHER	FILE_DEVICE_CUSTOM Function #1442
0xC350D1B7	high	METHOD_NEITHER	CUSTOM_MSI Function #1133
0x002200F0	medium	METHOD_BUFFERED	FILE_DEVICE_UNKNOWN Function #60
0x0080EC81	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #2848
0x00222008	medium	METHOD_BUFFERED	FILE_DEVICE_UNKNOWN Function #2050
0x0022208C	medium	METHOD_BUFFERED	FILE_DEVICE_UNKNOWN Function #2083
0x00802484	medium	METHOD_BUFFERED	FILE_DEVICE_CUSTOM Function #2337
0x00808889	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #546
0x0080CB15	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #709
0x0080E70D	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #2499
0x0080430D	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #195
0x0034472D	medium	METHOD_IN_DIRECT	FILE_DEVICE_DISK Function #459
0x0080007E	medium	METHOD_OUT_DIRECT	FILE_DEVICE_CUSTOM Function #31
0x0022341E	medium	METHOD_OUT_DIRECT	FILE_DEVICE_UNKNOWN Function #3335
0x0080C481	medium	METHOD_IN_DIRECT	FILE_DEVICE_CUSTOM Function #288
0x003403BC	medium	METHOD_BUFFERED	FILE_DEVICE_DISK Function #239

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	0xB157	0xB200	6.39	CODE, EXEC, READ
.rdata	0x1074	0x1200	4.77	IDATA, READ
.data	0x0FF4	0x0200	1.1	IDATA, READ, WRITE
.pdata	0x08B8	0x0A00	4.17	IDATA, READ
PAGESRP0	0x3124	0x3200	6.17	CODE, EXEC, READ
PAGE	0x0121	0x0200	4.05	CODE, EXEC, READ
PAGESER	0x01F3	0x0200	5.97	CODE, EXEC, READ
INIT	0x06B4	0x0800	5.15	CODE, EXEC, READ, DISCARD
.rsrc	0x0420	0x0600	2.53	IDATA, READ, DISCARD
.reloc	0x0030	0x0200	0.6	IDATA, READ, DISCARD

Exploit mitigations

Control Flow Guard	Not enabled
ASLR	Enabled
DEP	Enabled
Integrity check	Not enforced
Mitigation score	55 / 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.
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.

MITRE ATT&CK techniques (6)

Techniques this driver could enable if loaded by an adversary.

ID	Technique	Tactic
T1071	Application Layer Protocol	Command and Control
T1211	Exploitation for Defense Evasion	Defense Evasion
T1543.003	Windows Service	Persistence
T1553.002	Subvert Trust Controls: Code Signing	Defense Evasion
T1569.002	Service Execution	Execution
T1652	Device Driver Discovery	Discovery

Code-signing chain

Signer	Silicon Laboratories Inc.
Signer organisation	Silicon Laboratories Inc.
Issuer	Symantec Class 3 SHA256 Code Signing CA
Serial	4CDD2F3C085D4BA9675DB3D7397BEE33
Valid from	2015-11-04 00:00 UTC
Valid until	2018-11-03 23:59 UTC (expired)
Signature validity	Not verified

Certificate revision: 0x0200
Certificate type: PKCS#7
Chain: Symantec Class 3 SHA256 Code Signing CA
Chain: VeriSign Class 3 Public Primary Certification Authority - G5

Symbolic execution

Engine angr, status completed, 43 paths explored at a maximum depth of 43. Vulnerability classes reached: 0. Exploitable paths: 0.

Frequently asked questions about silabser.sys

Is silabser.sys safe?

Based on DriverShield static and dynamic analysis, silabser.sys is assessed as clean, with no notable risk signals. Its composite risk score is 14/100 (verdict: clean). Always validate findings independently before acting.

What is the risk score of silabser.sys?

silabser.sys has a DriverShield composite risk score of 14/100, placing it in the clean verdict band. SHA256: d1a4b2fa462dbdfed7e263df79e9f96f779eebc1026cd4d8e1c1bb31f48eeb69.

What is silabser.sys?

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

Related: Other drivers signed by Silicon Laboratories Inc. · What an IOCTL dispatch code is · BYOVD research index · full driver database · CVE library · code signing atlas