Analysis of ksthunk.sys: clean verdict, risk score 22/100. 0 YARA matches. SHA256 bcd26fd24a0cfc2d. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.
DriverShield analyzed the Windows kernel driver ksthunk.sys and assigned a verdict of Clean with a composite risk score of 22/100, indicating no notable risk signals (0-29 band).
| Verdict | Clean (22/100) |
| YARA matches | 0 |
| File size | 37376 bytes |
| Analyzed | 2026-03-22 |
| SHA256 | bcd26fd24a0cfc2d0c142430db78aeb900f6bcf1322e831d9a051e4dd6432f0f |
| SHA1 | 3fa5059369ee3d5e18177b3a17b5fe31b8427f3e |
| MD5 | 311347892d84a7e03872ed923d5f2514 |
Version resource data embedded in the ksthunk.sys PE header, as extracted by the analysis engine.
| File description | Kernel Streaming WOW Thunk Service |
|---|---|
| Product | Microsoft® Windows® Operating System |
| Company | Microsoft Corporation |
| Original filename | ksthunk.sys |
| Internal name | ksthunk.sys |
| File version | 10.0.19041.4957 (WinBuild.160101.0800) |
| Copyright | © Microsoft Corporation. All rights reserved. |
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 | 84 / 100 |
| IOCTL dispatch surface | 33 / 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-mode APIs resolved from the Import Address Table of ksthunk.sys, ranked by exploitation relevance.
| API | Risk | Why it matters |
|---|---|---|
| MmMapLockedPagesSpecifyCache | critical | Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination |
| MmGetSystemRoutineAddress | high | Potentially dangerous - could be used for privilege escalation or security bypass |
| KeSetEvent | low | Standard kernel API - generally benign |
| ExFreePool | low | Standard kernel API - generally benign |
| IoDeleteDevice | low | Standard kernel API - generally benign |
| IoCreateDevice | low | Standard kernel API - generally benign |
| ProbeForRead | low | Standard kernel API - generally benign |
| ProbeForWrite | low | Standard kernel API - generally benign |
| ZwClose | low | Standard kernel API - generally benign |
| KeWaitForSingleObject | low | Standard kernel API - generally benign |
| ExAllocatePoolWithTag | low | Standard kernel API - generally benign |
| RtlInitUnicodeString | low | Standard kernel API - generally benign |
| KeInitializeEvent | low | Standard kernel API - generally benign |
| IofCompleteRequest | low | Standard kernel API - generally benign |
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 |
|---|---|---|---|
| 0x002200F0 | medium | METHOD_BUFFERED | FILE_DEVICE_UNKNOWN Function #60 |
| 0x00802484 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #2337 |
| 0x00802494 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #2341 |
| 0x0080BB89 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #3810 |
| 0x00809484 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #1313 |
| 0x0080EC81 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #2848 |
| 0x0080249C | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #2343 |
| 0x0080E281 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #2208 |
| 0x0080BAF9 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #3774 |
| 0x003403B0 | medium | METHOD_BUFFERED | FILE_DEVICE_DISK Function #236 |
| 0x0034002E | medium | METHOD_OUT_DIRECT | FILE_DEVICE_DISK Function #11 |
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 | 0x38A9 | 0x3A00 | 6.09 | CODE, EXEC, READ |
| .rdata | 0x1140 | 0x1200 | 3.8 | IDATA, READ |
| .data | 0x0198 | 0x0200 | 0.38 | IDATA, READ, WRITE |
| .pdata | 0x0594 | 0x0600 | 4 | IDATA, READ |
| .idata | 0x0A8A | 0x0C00 | 4.28 | IDATA, READ |
| PAGE | 0x1938 | 0x1A00 | 5.98 | CODE, EXEC, READ |
| PAGECONS | 0x0080 | 0x0200 | 1.27 | IDATA, READ |
| INIT | 0x0352 | 0x0400 | 5.42 | CODE, EXEC, READ, DISCARD |
| GFIDS | 0x00F8 | 0x0200 | 2 | IDATA, READ, DISCARD |
| .rsrc | 0x0418 | 0x0600 | 2.52 | IDATA, READ, DISCARD |
| .reloc | 0x0498 | 0x0600 | 4.72 | IDATA, READ, DISCARD |
| Control Flow Guard | Enabled |
|---|---|
| ASLR | Enabled |
| DEP | Enabled |
| Integrity check | Not enforced |
| Mitigation score | 80 / 100 |
Techniques this driver could enable if loaded by an adversary.
| ID | Technique | Tactic |
|---|---|---|
| T1003.001 | OS Credential Dumping: LSASS Memory | Credential Access |
| T1055.012 | Process Hollowing | Defense Evasion |
| T1068 | Exploitation for Privilege Escalation | Privilege Escalation |
| T1211 | Exploitation for Defense Evasion | Defense Evasion |
| T1543.003 | Windows Service | Persistence |
| T1553.002 | Subvert Trust Controls: Code Signing | Defense Evasion |
| T1553.006 | Code Signing Policy Modification | Defense Evasion |
| T1569.002 | System Services: Service Execution | Execution |
| T1652 | Device Driver Discovery | Discovery |
Engine angr, status no_findings, 0 paths explored at a maximum depth of 0. Vulnerability classes reached: 0. Exploitable paths: 0.
Based on DriverShield static and dynamic analysis, ksthunk.sys is assessed as clean, with no notable risk signals. Its composite risk score is 22/100 (verdict: clean). Always validate findings independently before acting.
ksthunk.sys has a DriverShield composite risk score of 22/100, placing it in the clean verdict band. SHA256: bcd26fd24a0cfc2d0c142430db78aeb900f6bcf1322e831d9a051e4dd6432f0f.
ksthunk.sys is a Windows kernel-mode driver (.sys) analyzed by DriverShield for vulnerabilities, BYOVD abuse potential, and malware indicators.
Related: What an IOCTL dispatch code is · BYOVD research index · full driver database · CVE library · code signing atlas