wstlib64.sys

Webfuii

Part of the Yontoo adware component, a web browser plugin that injects unwanted ads in the browser. The file wstlib64.sys by Webfuii has been detected as adware by 1 anti-malware scanner with very strong indications that the file is a potential threat. It runs as a Windows 64-bit kernel mode device driver named “wStLib64”.
Publisher:
StdLib  (signed by Webfuii)

Product:
StdLib

Version:
1.4.3.1 built by: WinDDK

MD5:
f34aed6c3fba065560223862c7f9b23c

SHA-1:
1b19c053a2ff3b2791c94b51ad2cf6860d9781e2

SHA-256:
efd46043f0bfce2d17d6faf185e64dcde729340020fd5e75e8df3f5aa9e9edaf

Scanner detections:
1 / 68

Status:
Adware

Explanation:
Belongs to the Sambreel/Yontoo progam that inserts various forms of advertising in the user's web browser, installed with minimal or no user consent.

Analysis date:
4/24/2024 3:17:16 AM UTC  (today)

Scan engine
Detection
Engine version

Reason Heuristics
PUP.Yontoo.Webfuii (M)
15.12.10.11

File size:
59.7 KB (61,112 bytes)

Product version:
1.4.3.1

Copyright:
Copyright © 2013 StdLib

Original file name:
StdLib.sys

File type:
Driver (Win64 SYS)

Language:
English (United States)

Common path:
C:\Windows\System32\drivers\wstlib64.sys

Digital Signature
Signed by:

Authority:
VeriSign, Inc.

Valid from:
10/6/2013 5:00:00 PM

Valid to:
10/7/2014 4:59:59 PM

Subject:
CN=Webfuii, OU=Digital ID Class 3 - Microsoft Software Validation v2, O=Webfuii, L=San Diego, S=California, C=US

Issuer:
CN=VeriSign Class 3 Code Signing 2010 CA, OU=Terms of use at https://www.verisign.com/rpa (c)10, OU=VeriSign Trust Network, O="VeriSign, Inc.", C=US

Serial number:
658C92DE4B1AFFD7A1D69F49D0D049BA

File PE Metadata
Compilation timestamp:
1/30/2014 4:45:30 PM

OS version:
6.1

OS bitness:
Win64

Subsystem:
Native (none required)

Linker version:
9.0

CTPH (ssdeep):
768:Mot2dxF9O8ZF33iqiIy938bWp9XcfBvJkowidI3P:M9JRicy938ip9ea1j/

Entry address:
0xF064

Entry point:
48, 83, EC, 28, 4C, 8B, C2, 4C, 8B, C9, E8, 95, FF, FF, FF, 49, 8B, D0, 49, 8B, C9, 48, 83, C4, 28, E9, 2E, 20, FF, FF, CC, CC, 38, F2, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 1C, F6, 00, 00, 60, C1, 00, 00, 28, F1, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, BE, F9, 00, 00, 50, C0, 00, 00, D8, F0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, B6, FA, 00, 00, 00, C0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 9A, FA, 00, 00, 00, 00, 00, 00, 86, FA, 00, 00...
 
[+]

Entropy:
5.9629

Code size:
46.5 KB (47,616 bytes)

Driver
Display name:
wStLib64

Type:
Kernel device driver (KernelDriver)

Group:
PNP_TDI


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