Malware Analysis Report

2025-08-05 16:42

Sample ID 240204-wfpstahfel
Target 8fc7c1c53bb2b95576968a2bd3086b12
SHA256 a9b89e001fe382a51fc329470dde3cbc463c42386f53018054fb79710e9a333f
Tags
adware persistence stealer upx
score
8/10

Table of Contents

Analysis Overview

MITRE ATT&CK

Enterprise Matrix V15

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
8/10

SHA256

a9b89e001fe382a51fc329470dde3cbc463c42386f53018054fb79710e9a333f

Threat Level: Likely malicious

The file 8fc7c1c53bb2b95576968a2bd3086b12 was found to be: Likely malicious.

Malicious Activity Summary

adware persistence stealer upx

Modifies AppInit DLL entries

Loads dropped DLL

UPX packed file

Installs/modifies Browser Helper Object

Drops file in System32 directory

Unsigned PE

Modifies registry class

Suspicious use of WriteProcessMemory

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-02-04 17:52

Signatures

Unsigned PE

Description Indicator Process Target
N/A N/A N/A N/A

Analysis: behavioral1

Detonation Overview

Submitted

2024-02-04 17:52

Reported

2024-02-04 17:54

Platform

win7-20231215-en

Max time kernel

120s

Max time network

125s

Command Line

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

Signatures

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 2204 wrote to memory of 2876 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe

Processes

C:\Windows\system32\rundll32.exe

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

C:\Windows\SysWOW64\rundll32.exe

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

Network

N/A

Files

memory/2876-0-0x0000000010000000-0x000000001003F000-memory.dmp

memory/2876-1-0x0000000010000000-0x000000001003F000-memory.dmp

memory/2876-2-0x0000000000160000-0x0000000000179000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2024-02-04 17:52

Reported

2024-02-04 17:54

Platform

win10v2004-20231215-en

Max time kernel

138s

Max time network

155s

Command Line

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

Signatures

Modifies AppInit DLL entries

persistence

Loads dropped DLL

Description Indicator Process Target
N/A N/A C:\Windows\SysWOW64\rundll32.exe N/A

UPX packed file

upx
Description Indicator Process Target
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A

Installs/modifies Browser Helper Object

stealer adware
Description Indicator Process Target
Key deleted \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C} C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA} C:\Windows\SysWOW64\rundll32.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{08afb971-dd89-466b-8a4e-aeac60400ad1} C:\Windows\SysWOW64\rundll32.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{08afb971-dd89-466b-8a4e-aeac60400ad1}\ = "{1da00406-caea-e4a8-b664-98dd179bfa80}" C:\Windows\SysWOW64\rundll32.exe N/A

Drops file in System32 directory

Description Indicator Process Target
File created C:\Windows\SysWOW64\asumzu.dll C:\Windows\SysWOW64\rundll32.exe N/A
File opened for modification C:\Windows\SysWOW64\asumzu.dll C:\Windows\SysWOW64\rundll32.exe N/A

Modifies registry class

Description Indicator Process Target
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\Implemented Categories\{59FB2056-D625-48D0-A944-1A85B5AB2640} C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\Implemented Categories C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\Version C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\TypeLib C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\InprocServer32 C:\Windows\SysWOW64\rundll32.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node C:\Windows\SysWOW64\rundll32.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID C:\Windows\SysWOW64\rundll32.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{08afb971-dd89-466b-8a4e-aeac60400ad1} C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\VersionIndependentProgID C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\TypeLib C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\InprocServer32 C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C} C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\VersionIndependentProgID C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\Programmable C:\Windows\SysWOW64\rundll32.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{08afb971-dd89-466b-8a4e-aeac60400ad1}\InprocServer32\ThreadingModel = "free" C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\ProgID C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\ProgID C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\Implemented Categories\{59FB2056-D625-48D0-A944-1A85B5AB2640} C:\Windows\SysWOW64\rundll32.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{08afb971-dd89-466b-8a4e-aeac60400ad1}\InprocServer32\ = "C:\\Windows\\SysWow64\\asumzu.dll" C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{1FD49718-1D00-4B19-AF5F-070AF6D5D54C}\Programmable C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA}\Implemented Categories C:\Windows\SysWOW64\rundll32.exe N/A
Key deleted \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{31D09BA0-12F5-4CCE-BE8A-2923E76605DA} C:\Windows\SysWOW64\rundll32.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Classes\WOW6432Node\CLSID\{08afb971-dd89-466b-8a4e-aeac60400ad1}\InprocServer32 C:\Windows\SysWOW64\rundll32.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 64 wrote to memory of 4428 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 64 wrote to memory of 4428 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 64 wrote to memory of 4428 N/A C:\Windows\system32\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 4428 wrote to memory of 228 N/A C:\Windows\SysWOW64\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 4428 wrote to memory of 228 N/A C:\Windows\SysWOW64\rundll32.exe C:\Windows\SysWOW64\rundll32.exe
PID 4428 wrote to memory of 228 N/A C:\Windows\SysWOW64\rundll32.exe C:\Windows\SysWOW64\rundll32.exe

Processes

C:\Windows\system32\rundll32.exe

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

C:\Windows\SysWOW64\rundll32.exe

rundll32.exe C:\Users\Admin\AppData\Local\Temp\8fc7c1c53bb2b95576968a2bd3086b12.dll,#1

C:\Windows\SysWOW64\rundll32.exe

rundll32.exe "C:\Windows\system32\asumzu.dll",i

Network

Country Destination Domain Proto
US 138.91.171.81:80 tcp
US 8.8.8.8:53 149.220.183.52.in-addr.arpa udp
US 8.8.8.8:53 201.178.17.96.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 8.8.8.8:53 209.205.72.20.in-addr.arpa udp
US 8.8.8.8:53 157.123.68.40.in-addr.arpa udp
US 8.8.8.8:53 18.31.95.13.in-addr.arpa udp
US 8.8.8.8:53 217.135.221.88.in-addr.arpa udp
US 8.8.8.8:53 180.178.17.96.in-addr.arpa udp
US 8.8.8.8:53 43.229.111.52.in-addr.arpa udp
US 8.8.8.8:53 204.178.17.96.in-addr.arpa udp
US 8.8.8.8:53 10.173.189.20.in-addr.arpa udp

Files

memory/4428-0-0x0000000010000000-0x000000001003F000-memory.dmp

memory/4428-1-0x0000000000A80000-0x0000000000A99000-memory.dmp

memory/4428-2-0x0000000010000000-0x000000001003F000-memory.dmp

memory/4428-3-0x0000000010000000-0x000000001003F000-memory.dmp

memory/4428-4-0x0000000010000000-0x000000001003F000-memory.dmp

memory/4428-5-0x0000000010000000-0x000000001003F000-memory.dmp

memory/4428-8-0x0000000010000000-0x000000001003F000-memory.dmp

C:\Windows\SysWOW64\asumzu.dll

MD5 8fc7c1c53bb2b95576968a2bd3086b12
SHA1 46446c12d36457da232b495cc9c3a8596d4efad1
SHA256 a9b89e001fe382a51fc329470dde3cbc463c42386f53018054fb79710e9a333f
SHA512 efac4111b9582e14449c4a5284225300ad22c587a8db25652225dfba703f0a25cd0b282c9db03624e063336cfff36c662f6240d560ad912ab49077fda1ca2f18

memory/228-10-0x0000000010000000-0x000000001003F000-memory.dmp

memory/228-13-0x0000000010000000-0x000000001003F000-memory.dmp

memory/228-14-0x0000000010000000-0x000000001003F000-memory.dmp

memory/228-15-0x0000000010000000-0x000000001003F000-memory.dmp