Malware Analysis Report

2024-11-16 12:44

Sample ID 240302-yzgbwshd85
Target Chernobyl.exe
SHA256 8e25f551c62c72c1f47877affafb617992282b2e115c8c8977918fc6493aece3
Tags
discovery evasion exploit persistence trojan
score
10/10

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 Overview

score
10/10

SHA256

8e25f551c62c72c1f47877affafb617992282b2e115c8c8977918fc6493aece3

Threat Level: Known bad

The file Chernobyl.exe was found to be: Known bad.

Malicious Activity Summary

discovery evasion exploit persistence trojan

UAC bypass

Modifies WinLogon for persistence

Disables RegEdit via registry modification

Possible privilege escalation attempt

Disables Task Manager via registry modification

Modifies file permissions

Modifies WinLogon

Checks whether UAC is enabled

Drops file in System32 directory

Drops file in Windows directory

Unsigned PE

Enumerates physical storage devices

System policy modification

Suspicious use of AdjustPrivilegeToken

Suspicious use of WriteProcessMemory

Modifies registry class

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-03-02 20:13

Signatures

Unsigned PE

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

Analysis: behavioral1

Detonation Overview

Submitted

2024-03-02 20:13

Reported

2024-03-02 20:14

Platform

win7-20240221-en

Max time kernel

34s

Max time network

19s

Command Line

"C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe"

Signatures

Modifies WinLogon for persistence

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, cluttscape.exe" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

UAC bypass

evasion trojan
Description Indicator Process Target
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Disables RegEdit via registry modification

evasion
Description Indicator Process Target
Set value (int) \REGISTRY\USER\S-1-5-21-406356229-2805545415-1236085040-1000\Software\Microsoft\Windows\CurrentVersion\Policies\System\DisableRegistryTools = "1" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Disables Task Manager via registry modification

evasion

Checks whether UAC is enabled

evasion trojan
Description Indicator Process Target
Key value queried \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Modifies WinLogon

persistence
Description Indicator Process Target
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\AutoRestartShell = "0" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\DisableCAD = "1" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Drops file in System32 directory

Description Indicator Process Target
File opened for modification C:\Windows\SysWOW64\kill.ico C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Drops file in Windows directory

Description Indicator Process Target
File created C:\Windows\cluttscape.exe C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
File opened for modification C:\Windows\cluttscape.exe C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Enumerates physical storage devices

Modifies registry class

Description Indicator Process Target
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Classes\Unknown\DefaultIcon\ = "C:\\Windows\\SysWow64\\kill.ico" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeTakeOwnershipPrivilege N/A C:\Windows\SysWOW64\takeown.exe N/A
Token: SeShutdownPrivilege N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 2192 wrote to memory of 844 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 844 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 844 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 844 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 844 wrote to memory of 2996 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\rundll32.exe
PID 2192 wrote to memory of 1492 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1492 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1492 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1492 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 1492 wrote to memory of 1532 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1492 wrote to memory of 1532 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1492 wrote to memory of 1532 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1492 wrote to memory of 1532 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2192 wrote to memory of 1512 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1512 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1512 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1512 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 1512 wrote to memory of 1516 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1512 wrote to memory of 1516 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1512 wrote to memory of 1516 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1512 wrote to memory of 1516 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2192 wrote to memory of 2860 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2860 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2860 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2860 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2860 wrote to memory of 1580 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2860 wrote to memory of 1580 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2860 wrote to memory of 1580 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2860 wrote to memory of 1580 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2860 wrote to memory of 1708 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\icacls.exe
PID 2860 wrote to memory of 1708 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\icacls.exe
PID 2860 wrote to memory of 1708 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\icacls.exe
PID 2860 wrote to memory of 1708 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\icacls.exe
PID 2192 wrote to memory of 1340 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1340 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1340 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 1340 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 1340 wrote to memory of 2692 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1340 wrote to memory of 2692 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1340 wrote to memory of 2692 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 1340 wrote to memory of 2692 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2192 wrote to memory of 2496 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2496 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2496 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2496 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2496 wrote to memory of 2512 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2496 wrote to memory of 2512 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2496 wrote to memory of 2512 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2496 wrote to memory of 2512 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2192 wrote to memory of 2508 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2508 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2508 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2192 wrote to memory of 2508 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe
PID 2508 wrote to memory of 2628 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2508 wrote to memory of 2628 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2508 wrote to memory of 2628 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2508 wrote to memory of 2628 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\takeown.exe
PID 2192 wrote to memory of 2680 N/A C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe C:\Windows\SysWOW64\cmd.exe

System policy modification

evasion
Description Indicator Process Target
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\shutdownwithoutlogon = "0" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\UseDefaultTile = "1" C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe N/A

Processes

C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe

"C:\Users\Admin\AppData\Local\Temp\Chernobyl.exe"

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k start RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters && exit

C:\Windows\SysWOW64\rundll32.exe

RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\smss.exe && icacls C:\Windows\System32\smss.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\smss.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\csrss.exe && icacls C:\Windows\System32\csrss.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\csrss.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\wininit.exe && icacls C:\Windows\System32\wininit.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\wininit.exe

C:\Windows\SysWOW64\icacls.exe

icacls C:\Windows\System32\wininit.exe /grant "Admin:F"

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\LogonUI.exe && icacls C:\Windows\System32\LogonUI.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\LogonUI.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\lsass.exe && icacls C:\Windows\System32\lsass.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\lsass.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\services.exe && icacls C:\Windows\System32\services.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\services.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\winlogon.exe && icacls C:\Windows\System32\winlogon.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\winlogon.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\winload.efi && icacls C:\Windows\System32\winload.efi /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\winload.efi

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\winload.exe && icacls C:\Windows\System32\winload.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\winload.exe

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\ntoskrnl.exe && icacls C:\Windows\System32\ntoskrnl.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\ntoskrnl.exe

C:\Windows\SysWOW64\icacls.exe

icacls C:\Windows\System32\ntoskrnl.exe /grant "Admin:F"

C:\Windows\SysWOW64\cmd.exe

"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32\svchost.exe && icacls C:\Windows\System32\svchost.exe /grant "%username%:F" && exit

C:\Windows\SysWOW64\takeown.exe

takeown /f C:\Windows\System32\svchost.exe

C:\Windows\SysWOW64\icacls.exe

icacls C:\Windows\System32\svchost.exe /grant "Admin:F"

Network

N/A

Files

memory/2192-0-0x0000000000050000-0x00000000000AC000-memory.dmp

memory/2192-1-0x0000000074C10000-0x00000000752FE000-memory.dmp

C:\Users\Admin\Desktop\Æń63≈ø√¶4¥σœÆ■¬ñ█½ÿ√♦♣╚ó«☼¾♦6♦♥▬ž♪¾╠™ε™φφÆσ¼7õφΣö■♫╧í▼φ6č○ñπ♦Ÿ╚5ßš£σóñ♫¾šσ1ö×ñ≈♪õΣ◄¶åΣ☼↕↕♥ñ♂♫æÿ▬3◄æ

MD5 9e1e5883c74742a497cf5c272ccd2321
SHA1 2cf33e34d08b8e17743a60352baffef4b6f02dee
SHA256 ca687b6a7c3d29b566f3e1988b9f877b51d9a83ee25ffe0755a8dcd3eb5f434a
SHA512 f2284f0c624cc07a65c16f87865bb98aaa176b1d8b45cd4fbcc1143c9c2297fe6b1d4db55ef054be2bc151c8cc25ff4da7c997b7d38dae3dccd2ffe1c3c01a6b

memory/2192-306-0x0000000005370000-0x00000000053B0000-memory.dmp

memory/2192-307-0x0000000005370000-0x00000000053B0000-memory.dmp

memory/2192-308-0x0000000074C10000-0x00000000752FE000-memory.dmp

memory/2192-309-0x0000000005370000-0x00000000053B0000-memory.dmp