wstlib.sys

monetomi

Part of the Yontoo adware component, a web browser plugin that injects unwanted ads in the browser. The file wstlib.sys by monetomi 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 kernel mode device driver named “wStLib”.
Publisher:
StdLib  (signed by monetomi)

Product:
StdLib

Version:
1.4.3.1 built by: WinDDK

MD5:
eb8c31cb9463f50f38504218def17467

SHA-1:
e7aa9b1f21f992040273804fbbcefa663ce5e6a7

SHA-256:
df8d2b16e42f9c9db28c3b807bcdd88263771ca355e2f4279b61a1e31bedc2ff

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:
4/25/2024 6:19:55 PM UTC  (today)

Scan engine
Detection
Engine version

Reason Heuristics
PUP.Yontoo.monetomi (M)
16.2.9.4

File size:
51.7 KB (52,920 bytes)

Product version:
1.4.3.1

Copyright:
Copyright © 2013 StdLib

Original file name:
StdLib.sys

File type:
Driver (Win32 SYS)

Language:
English (United States)

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

Digital Signature
Signed by:

Authority:
VeriSign, Inc.

Valid from:
8/20/2013 5:00:00 PM

Valid to:
8/20/2015 4:59:59 PM

Subject:
CN=monetomi, OU=Digital ID Class 3 - Microsoft Software Validation v2, O=monetomi, 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:
7B85B21935E66C13ED590CCA42A5E4E3

File PE Metadata
Compilation timestamp:
1/30/2014 4:45:28 PM

OS version:
6.1

OS bitness:
Win32

Subsystem:
Native (none required)

Linker version:
9.0

CTPH (ssdeep):
768:pIsHpnKHCBSqUPJHKQpkJxpKwT2bcWiJmOtX3g2rp3lnT5M:msHRKHLJqQpkYwTsiTtXxt9M

Entry address:
0xC03E

Entry point:
8B, FF, 55, 8B, EC, E8, BD, FF, FF, FF, 5D, E9, 62, 50, FF, FF, CC, CC, 74, C1, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, BC, C4, 00, 00, C0, A0, 00, 00, B4, C0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 12, C5, 00, 00, 00, A0, 00, 00, EC, C0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, AE, C8, 00, 00, 38, A0, 00, 00, C4, C0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, A6, C9, 00, 00, 10, A0, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, EA, C4, 00, 00, FE, C4, 00, 00, D6, C4...
 
[+]

Entropy:
6.3567

Code size:
37 KB (37,888 bytes)

Driver
Display name:
wStLib

Type:
Kernel device driver (KernelDriver)

Group:
PNP_TDI


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