dfae05e160c6bd5a0cb096d813daab037d74e36e20718bb71e5f8165e22096aa

Analysis

max time kernel
116s
max time network
147s
platform
windows10-2004_x64
resource
win10v2004-20240426-en
resource tags

arch:x64arch:x86image:win10v2004-20240426-enlocale:en-usos:windows10-2004-x64system
submitted
03/06/2024, 10:36

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General

Target
CSharp-WinLocker.exe
Size 20KB
Sample240603-mnrspscg66
SHA256 dfae05e160c6bd5a0cb096d813daab037d74e36e20718bb71e5f8165e22096aa
MD5 8cee89d9fe57724ede88d6b4acca3d56
SHA1 50a95af04c4708f7227c4f05435f5ffe49372631
SHA512 efa518124a197655ef8c291d3868ce1ab1709bcf10e0cb2b6d3774df967a9da6d3047f921f73eb6d33c0cbbc527f7d7292082832d39a558f9140bda044039a15
SSDEEP 384:QWsneH5tPSlP8neaXd1fQUhb/gw/y7G0Bz2cHnPnVA0fZXAdptYcFwVc03K:QWZvDeaXQC/g/FRlvnHXAvtYcFwVc6K
MD5 SHA1 SHA512 SSDEEP

Score

10^/10

evasion persistence trojan

Malware Config

Signatures

Modifies WinLogon for persistence 2 TTPs 1 IoCs

persistence

Winlogon Helper DLL

T1547.004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3571316656-3665257725-2415531812-1000\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe

UAC bypass 3 TTPs 1 IoCs

evasion trojan

Bypass User Account Control

T1548.002

Disable or Modify Tools

T1562.001

Modify Registry

T1112

description	ioc	Process
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0"	CSharp-WinLocker.exe

Sets file execution options in registry 2 TTPs 10 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedit.exe\Debugger = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe	CSharp-WinLocker.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe\Debugger = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\regedit.exe	CSharp-WinLocker.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\utilman.exe\Debugger = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\reg.exe	CSharp-WinLocker.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\reg.exe\Debugger = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe	CSharp-WinLocker.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\taskmgr.exe\Debugger = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\utilman.exe	CSharp-WinLocker.exe

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\RunOnce\Java = "C:\\Users\\Admin\\AppData\\Local\\Temp\\CSharp-WinLocker.exe"	CSharp-WinLocker.exe

Checks whether UAC is enabled 1 TTPs 2 IoCs

evasion trojan

System Information Discovery

T1082

description	ioc	Process
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0"	CSharp-WinLocker.exe
Key value queried	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA	CSharp-WinLocker.exe

Creates scheduled task(s) 1 TTPs 1 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence

Scheduled Task/Job

T1053

pid	Process
4184	schtasks.exe

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
3256	CSharp-WinLocker.exe

Suspicious behavior: GetForegroundWindowSpam 1 IoCs

pid	Process
3256	CSharp-WinLocker.exe

Suspicious use of AdjustPrivilegeToken 1 IoCs

description	pid	Process
Token: SeDebugPrivilege	3256	CSharp-WinLocker.exe

Suspicious use of WriteProcessMemory 6 IoCs

description	pid	Process	procid_target
PID 3256 wrote to memory of 5068	3256	CSharp-WinLocker.exe	85
PID 3256 wrote to memory of 5068	3256	CSharp-WinLocker.exe	85
PID 3256 wrote to memory of 5068	3256	CSharp-WinLocker.exe	85
PID 3256 wrote to memory of 4184	3256	CSharp-WinLocker.exe	87
PID 3256 wrote to memory of 4184	3256	CSharp-WinLocker.exe	87
PID 3256 wrote to memory of 4184	3256	CSharp-WinLocker.exe	87

System policy modification 1 TTPs 2 IoCs

evasion

Modify Registry

T1112

description	ioc	Process
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0"	CSharp-WinLocker.exe
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\HideFastUserSwitching = "1"	CSharp-WinLocker.exe

C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
"C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe"
1⤵
- Modifies WinLogon for persistence
- UAC bypass
- Sets file execution options in registry
- Adds Run key to start application
- Checks whether UAC is enabled
- Suspicious behavior: EnumeratesProcesses
- Suspicious behavior: GetForegroundWindowSpam
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
- System policy modification
PID:3256
- C:\Windows\SysWOW64\schtasks.exe
  "schtasks" /delete /f /tn "OneDrive"
  2⤵
  PID:5068
- C:\Windows\SysWOW64\schtasks.exe
  "schtasks" /create /tn "OneDrive" /sc MINUTE /mo 1 /tr "C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe" /rl HIGHEST /f
  2⤵
  - Creates scheduled task(s)
  PID:4184

C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe explorer.exe
1⤵
PID:4524

C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
1⤵
PID:2388

C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
C:\Users\Admin\AppData\Local\Temp\CSharp-WinLocker.exe
1⤵
PID:3788

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Persistence

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Winlogon Helper DLL

T1547.004

Scheduled Task/Job

T1053

Privilege Escalation

Abuse Elevation Control Mechanism

T1548

Bypass User Account Control

T1548.002

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Winlogon Helper DLL

T1547.004

Scheduled Task/Job

T1053

Defense Evasion

Abuse Elevation Control Mechanism

T1548

Bypass User Account Control

T1548.002

Impair Defenses

T1562

Disable or Modify Tools

T1562.001

Modify Registry

T1112

Credential Access

Discovery

System Information Discovery

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

CSharp-WinLocker.exe.log

Path C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0_32\UsageLogs\CSharp-WinLocker.exe.log
Size 410B
SHA256 d9c6d00fad02f7a9ef0fcddc298ffd58b17020fb12b1336d5733237cbfadb1e0
MD5 3bbb825ef1319deb378787046587112b
SHA1 67da95f0031be525b4cf10645632ca34d66b913b
SHA512 7771ae543e188d544e1bb6c65e0453a6777c1c39790a355f4cce652a815bfaf94dd426de3db910a67bd06e463ac0143d9e2ca44d2b12af7f0d84c27b4a09cc54
MD5 SHA1 SHA512

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memory/2388-13-0x0000000074530000-0x0000000074CE0000-memory.dmp

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memory/2388-12-0x0000000074530000-0x0000000074CE0000-memory.dmp

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memory/3256-10-0x0000000074530000-0x0000000074CE0000-memory.dmp

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memory/3256-4-0x0000000005B30000-0x0000000005B3A000-memory.dmp

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memory/3256-5-0x0000000074530000-0x0000000074CE0000-memory.dmp

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memory/3256-9-0x000000007453E000-0x000000007453F000-memory.dmp

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memory/3256-0-0x000000007453E000-0x000000007453F000-memory.dmp

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memory/3256-3-0x0000000005960000-0x00000000059F2000-memory.dmp

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memory/3256-2-0x0000000005E30000-0x00000000063D4000-memory.dmp

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memory/3256-1-0x0000000000FB0000-0x0000000000FBA000-memory.dmp

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memory/4524-6-0x0000000074530000-0x0000000074CE0000-memory.dmp

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memory/4524-8-0x0000000074530000-0x0000000074CE0000-memory.dmp

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