Analysis of mskssrv.sys: vulnerable verdict, risk score 72/100. 0 YARA matches. SHA256 35b099978c29af88. Kernel imports, IOCTL codes, MITRE ATT&CK, and code-signing details.
DriverShield analyzed the Windows kernel driver mskssrv.sys and assigned a verdict of Vulnerable with a composite risk score of 72/100, indicating a known or likely vulnerability surface (60-79 band).
| Verdict | Vulnerable (72/100) |
| YARA matches | 0 |
| File size | 38400 bytes |
| Analyzed | 2026-03-22 |
| SHA256 | 35b099978c29af886a8947931133829dd095ef38026e5bb45c95f61c63261e40 |
| SHA1 | 47eb81cdfa8ee06037ff92908a296da179b95840 |
| MD5 | bebdb08db5a26d5e4e53be7824aced4b |
Version resource data embedded in the mskssrv.sys PE header, as extracted by the analysis engine.
| File description | MS KS Server |
|---|---|
| Product | Microsoft® Windows® Operating System |
| Company | Microsoft Corporation |
| Original filename | mskssrv.sys |
| Internal name | mskssrv.sys |
| File version | 10.0.19041.5007 (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 | 100 / 100 |
| IOCTL dispatch surface | 78 / 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 mskssrv.sys, ranked by exploitation relevance.
| API | Risk | Why it matters |
|---|---|---|
| MmMapLockedPagesSpecifyCache | critical | Highly dangerous - potential for arbitrary code execution, memory corruption, or process termination |
| ObOpenObjectByPointer | medium | Moderate risk - system modification capability |
| ZwSetValueKey | medium | Moderate risk - system modification capability |
| ObReferenceObjectByHandle | medium | Moderate risk - system modification capability |
| IoDeleteDevice | low | Standard kernel API - generally benign |
| ExFreePool | low | Standard kernel API - generally benign |
| ZwQueryValueKey | low | Standard kernel API - generally benign |
| ExAllocatePoolWithTag | low | Standard kernel API - generally benign |
| IoCreateDevice | low | Standard kernel API - generally benign |
| KeSetEvent | low | Standard kernel API - generally benign |
| KeWaitForSingleObject | low | Standard kernel API - generally benign |
| RtlInitUnicodeString | low | Standard kernel API - generally benign |
| IofCompleteRequest | low | Standard kernel API - generally benign |
| ZwClose | low | Standard kernel API - generally benign |
| DbgPrintEx | 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 |
|---|---|---|---|
| 0x00222000 | medium (known exploit) | METHOD_BUFFERED | Driver communication init |
| 0x002200F0 | medium | METHOD_BUFFERED | FILE_DEVICE_UNKNOWN Function #60 |
| 0x0080AFE8 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #3066 |
| 0x00806FE8 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #3066 |
| 0x00340031 | medium | METHOD_IN_DIRECT | FILE_DEVICE_DISK Function #12 |
| 0x00340042 | medium | METHOD_OUT_DIRECT | FILE_DEVICE_DISK Function #16 |
| 0x0080E281 | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #2208 |
| 0x0080BD8D | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #3939 |
| 0x0080B68D | medium | METHOD_IN_DIRECT | FILE_DEVICE_CUSTOM Function #3491 |
| 0x0080B978 | medium | METHOD_BUFFERED | FILE_DEVICE_CUSTOM Function #3678 |
| 0x00340384 | medium | METHOD_BUFFERED | FILE_DEVICE_DISK Function #225 |
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 | 0x17A9 | 0x1800 | 6.04 | CODE, EXEC, READ |
| .rdata | 0x0DC0 | 0x0E00 | 4.7 | IDATA, READ |
| .data | 0x00E0 | 0x0200 | 0.28 | IDATA, READ, WRITE |
| .pdata | 0x0564 | 0x0600 | 3.93 | IDATA, READ |
| .idata | 0x0B30 | 0x0C00 | 4.19 | IDATA, READ |
| .guids | 0x0030 | 0x0200 | 0.85 | IDATA, READ |
| PAGE | 0x4436 | 0x4600 | 6.06 | CODE, EXEC, READ |
| INIT | 0x0382 | 0x0400 | 5.48 | CODE, EXEC, READ, DISCARD |
| GFIDS | 0x0078 | 0x0200 | 1.01 | IDATA, READ, DISCARD |
| .rsrc | 0x03E8 | 0x0400 | 3.31 | IDATA, READ, DISCARD |
| .reloc | 0x045C | 0x0600 | 4.49 | 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 |
| T1055.001 | Process Injection: DLL Injection | Defense Evasion |
| T1055.012 | Process Hollowing | Defense Evasion |
| T1068 | Exploitation for Privilege Escalation | Privilege Escalation |
| T1211 | Exploitation for Defense Evasion | Defense Evasion |
| T1489 | Service Stop | Impact |
| T1543.003 | Windows Service | Persistence |
| T1553.002 | Subvert Trust Controls: Code Signing | Defense Evasion |
| T1553.006 | Code Signing Policy Modification | Defense Evasion |
| T1562.001 | Impair Defenses: Disable/Modify Tools | Defense Evasion |
| T1569.002 | System Services: Service Execution | Execution |
| T1652 | Device Driver Discovery | Discovery |
Engine angr, status static_approximation, 0 paths explored at a maximum depth of 0. Vulnerability classes reached: 0. Exploitable paths: 1.
Based on DriverShield static and dynamic analysis, mskssrv.sys is flagged as vulnerable and is a potential Bring Your Own Vulnerable Driver (BYOVD) risk. Its composite risk score is 72/100 (verdict: vulnerable). Always validate findings independently before acting.
mskssrv.sys has a DriverShield composite risk score of 72/100, placing it in the vulnerable verdict band. SHA256: 35b099978c29af886a8947931133829dd095ef38026e5bb45c95f61c63261e40.
mskssrv.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