Analysis of fs_rec.sys: clean verdict, risk score 13/100. 0 YARA matches, 0/74 multi-engine detections. SHA256 799c95dec7812205. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.
DriverShield analyzed the Windows kernel driver fs_rec.sys and assigned a verdict of Clean with a composite risk score of 13/100, indicating no notable risk signals (0-29 band).
| Verdict | Clean (13/100) |
| YARA matches | 0 |
| Multi-engine detections | 0 / 74 |
| File size | 71072 bytes |
| Code-signing signer | Microsoft Windows |
| Analyzed | 2026-10-11 |
| SHA256 | 799c95dec78122055300086193767662a6798b537e21ab2e7b9860be1e252ea3 |
| SHA1 | 4c258a7c69d8fc901db308f849119519b2b18ebd |
| MD5 | 788bae29776abebe05f1efa3a3f7747a |
Version resource data embedded in the fs_rec.sys PE header, as extracted by the analysis engine.
| File description | File System Recognizer Driver |
|---|---|
| Product | Microsoft® Windows® Operating System |
| Company | Microsoft Corporation |
| Original filename | fs_rec.sys |
| Internal name | fs_rec.sys |
| File version | 10.0.26100.1 (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 | 36 / 100 |
| IOCTL dispatch surface | 21 / 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-mode APIs resolved from the Import Address Table of fs_rec.sys, ranked by exploitation relevance.
| API | Risk | Why it matters |
|---|---|---|
| ExAllocatePoolWithTag | low | Standard kernel API - generally benign |
| KeInitializeEvent | low | Standard kernel API - generally benign |
| IoCreateDevice | low | Standard kernel API - generally benign |
| IoBuildDeviceIoControlRequest | low | Standard kernel API - generally benign |
| KeWaitForSingleObject | low | Standard kernel API - generally benign |
| RtlInitUnicodeString | low | Standard kernel API - generally benign |
| ZwCreateFile | low | Standard kernel API - generally benign |
| KeSetEvent | low | Standard kernel API - generally benign |
| ZwClose | 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 |
|---|---|---|---|
| 0x00340117 | high | METHOD_NEITHER | FILE_DEVICE_DISK Function #69 |
| 0x002200F0 | medium | METHOD_BUFFERED | FILE_DEVICE_UNKNOWN Function #60 |
| 0x00800080 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #32 |
| 0x008000BA | medium | METHOD_OUT_DIRECT | FILE_DEVICE_CUSTOM Function #46 |
| 0x0080249C | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #2343 |
| 0x0080FA81 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #3744 |
| 0x00340398 | medium | METHOD_BUFFERED | FILE_DEVICE_DISK Function #230 |
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 | 0x0B77 | 0x1000 | 4.46 | CODE, EXEC, READ |
| fothk | 0x1000 | 0x1000 | 0.02 | CODE, EXEC, READ |
| .rdata | 0x1034 | 0x2000 | 2.43 | IDATA, READ |
| .data | 0x02A0 | 0x1000 | 0.19 | IDATA, READ, WRITE |
| .pdata | 0x039C | 0x1000 | 1.22 | IDATA, READ |
| .idata | 0x033E | 0x1000 | 1.18 | IDATA, READ |
| PAGE | 0x2B80 | 0x3000 | 5.96 | CODE, EXEC, READ |
| INIT | 0x0525 | 0x1000 | 2.55 | CODE, EXEC, READ, DISCARD |
| GFIDS | 0x0030 | 0x1000 | 0.07 | IDATA, READ, DISCARD |
| .rsrc | 0x0408 | 0x1000 | 1.08 | IDATA, READ, DISCARD |
| .reloc | 0x02B4 | 0x1000 | 1.04 | IDATA, READ, DISCARD |
| Control Flow Guard | Enabled |
|---|---|
| ASLR | Enabled |
| DEP | Enabled |
| Integrity check | Not enforced |
| Mitigation score | 85 / 100 |
Techniques this driver could enable if loaded by an adversary.
| ID | Technique | Tactic |
|---|---|---|
| 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 |
| T1569.002 | System Services: Service Execution | Execution |
| T1652 | Device Driver Discovery | Discovery |
| Signer | Microsoft Windows |
|---|---|
| Signer organisation | Microsoft Corporation |
| Issuer | Microsoft Windows Production PCA 2011 |
| Serial | 3300000460CF42A912315F6FB3000000000460 |
| Valid from | 2023-11-16 19:20 UTC |
| Valid until | 2024-11-14 19:20 UTC (expired) |
| Signature validity | Not verified |
Engine angr, status static_approximation, 0 paths explored at a maximum depth of 0. Vulnerability classes reached: 1. Exploitable paths: 0.
Based on DriverShield static and dynamic analysis, fs_rec.sys is assessed as clean, with no notable risk signals. Its composite risk score is 13/100 (verdict: clean). Always validate findings independently before acting.
fs_rec.sys has a DriverShield composite risk score of 13/100, placing it in the clean verdict band. SHA256: 799c95dec78122055300086193767662a6798b537e21ab2e7b9860be1e252ea3.
fs_rec.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