Analysis Overview
SHA256
a9b89e001fe382a51fc329470dde3cbc463c42386f53018054fb79710e9a333f
Threat Level: Likely malicious
The file 8fc7c1c53bb2b95576968a2bd3086b12 was found to be: Likely malicious.
Malicious Activity Summary
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
Enterprise Matrix V15
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
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
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
Signatures
Modifies AppInit DLL entries
Loads dropped DLL
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Windows\SysWOW64\rundll32.exe | N/A |
UPX packed file
| 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
| 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