918bc31cba93f294e71233e9b029705706175be78ca6fff523fb4b5ba87dbfce

General

Target

letsvpn3.10.4Install.exe
Size

15.3MB
MD5

9e07c23a29b69024cc8cd6b0ee856b6c
SHA1

c0a6c67d609c9d4adcb3b2b13f65e5eda0c9fbeb
SHA256

918bc31cba93f294e71233e9b029705706175be78ca6fff523fb4b5ba87dbfce
SHA512

3b45a5d1657d18c336df7c64eac1a6b365a7d881a22d6d30944c3d2a8b994e0d07c2a0a91afd6999b6d559abc0ae29d065a95c55ac7b0a74e3d77e2f257d11dc
SSDEEP

393216:qE9AqYuf1pK6o217nb2LLhY8iuakhNrjcJp:3tf1ppzsLhHiEoJp

Score

10^/10

discovery evasion execution trojan

Malware Config

Extracted

Credentials

Protocol: ftp
Host:
134.122.155.46
Port:
21
Username:
lz165404
Password:
lz165404.

Signatures

UAC bypass 3 TTPs 2 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\ConsentPromptBehaviorAdmin = "0"	GPUChecker.exe
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\PromptOnSecureDesktop = "0"	GPUChecker.exe

Executes dropped EXE 3 IoCs

pid	Process
2232	letsvpn3.10.4Install.tmp
2560	GPUChecker.exe
2892	letsvpn-3.10.3.exe

Loads dropped DLL 9 IoCs

pid	Process
2360	letsvpn3.10.4Install.exe
2232	letsvpn3.10.4Install.tmp
2232	letsvpn3.10.4Install.tmp
2232	letsvpn3.10.4Install.tmp
2232	letsvpn3.10.4Install.tmp
2232	letsvpn3.10.4Install.tmp
2892	letsvpn-3.10.3.exe
2892	letsvpn-3.10.3.exe
2892	letsvpn-3.10.3.exe

Checks installed software on the system 1 TTPs
Looks up Uninstall key entries in the registry to enumerate software on the system.
discovery

Query Registry
T1012

Enumerates connected drives 3 TTPs 22 IoCs

Attempts to read the root path of hard drives other than the default C: drive.

Query Registry

T1012

Peripheral Device Discovery

T1120

System Information Discovery

T1082

description	ioc	Process
File opened (read-only)	\??\U:	GPUChecker.exe
File opened (read-only)	\??\B:	GPUChecker.exe
File opened (read-only)	\??\I:	GPUChecker.exe
File opened (read-only)	\??\K:	GPUChecker.exe
File opened (read-only)	\??\M:	GPUChecker.exe
File opened (read-only)	\??\P:	GPUChecker.exe
File opened (read-only)	\??\Y:	GPUChecker.exe
File opened (read-only)	\??\G:	GPUChecker.exe
File opened (read-only)	\??\J:	GPUChecker.exe
File opened (read-only)	\??\R:	GPUChecker.exe
File opened (read-only)	\??\W:	GPUChecker.exe
File opened (read-only)	\??\X:	GPUChecker.exe
File opened (read-only)	\??\Q:	GPUChecker.exe
File opened (read-only)	\??\T:	GPUChecker.exe
File opened (read-only)	\??\V:	GPUChecker.exe
File opened (read-only)	\??\S:	GPUChecker.exe
File opened (read-only)	\??\Z:	GPUChecker.exe
File opened (read-only)	\??\E:	GPUChecker.exe
File opened (read-only)	\??\H:	GPUChecker.exe
File opened (read-only)	\??\L:	GPUChecker.exe
File opened (read-only)	\??\N:	GPUChecker.exe
File opened (read-only)	\??\O:	GPUChecker.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

Using powershell.exe command.

execution

PowerShell

T1059.001

pid	Process
2640	powershell.exe

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 4 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	letsvpn3.10.4Install.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	letsvpn3.10.4Install.tmp
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	letsvpn-3.10.3.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	powershell.exe

Checks processor information in registry 2 TTPs 2 IoCs

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

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key opened	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\	GPUChecker.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString	GPUChecker.exe

Suspicious behavior: EnumeratesProcesses 9 IoCs

pid	Process
2232	letsvpn3.10.4Install.tmp
2232	letsvpn3.10.4Install.tmp
2640	powershell.exe
2560	GPUChecker.exe
2560	GPUChecker.exe
2560	GPUChecker.exe
2560	GPUChecker.exe
2560	GPUChecker.exe
2560	GPUChecker.exe

Suspicious behavior: GetForegroundWindowSpam 2 IoCs

pid	Process
2560	GPUChecker.exe
2892	letsvpn-3.10.3.exe

Suspicious use of AdjustPrivilegeToken 1 IoCs

description	pid	Process
Token: SeDebugPrivilege	2640	powershell.exe

Suspicious use of FindShellTrayWindow 1 IoCs

pid	Process
2232	letsvpn3.10.4Install.tmp

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
2560	GPUChecker.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2360 wrote to memory of 2232	2360	letsvpn3.10.4Install.exe	31
PID 2232 wrote to memory of 2560	2232	letsvpn3.10.4Install.tmp	32
PID 2232 wrote to memory of 2560	2232	letsvpn3.10.4Install.tmp	32
PID 2232 wrote to memory of 2560	2232	letsvpn3.10.4Install.tmp	32
PID 2232 wrote to memory of 2560	2232	letsvpn3.10.4Install.tmp	32
PID 2232 wrote to memory of 2892	2232	letsvpn3.10.4Install.tmp	33
PID 2232 wrote to memory of 2892	2232	letsvpn3.10.4Install.tmp	33
PID 2232 wrote to memory of 2892	2232	letsvpn3.10.4Install.tmp	33
PID 2232 wrote to memory of 2892	2232	letsvpn3.10.4Install.tmp	33
PID 2892 wrote to memory of 2640	2892	letsvpn-3.10.3.exe	34
PID 2892 wrote to memory of 2640	2892	letsvpn-3.10.3.exe	34
PID 2892 wrote to memory of 2640	2892	letsvpn-3.10.3.exe	34
PID 2892 wrote to memory of 2640	2892	letsvpn-3.10.3.exe	34

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\ConsentPromptBehaviorAdmin = "0"	GPUChecker.exe
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\PromptOnSecureDesktop = "0"	GPUChecker.exe

C:\Users\Admin\AppData\Local\Temp\letsvpn3.10.4Install.exe
"C:\Users\Admin\AppData\Local\Temp\letsvpn3.10.4Install.exe"
1⤵
- Loads dropped DLL
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:2360
- C:\Users\Admin\AppData\Local\Temp\is-9K2R3.tmp\letsvpn3.10.4Install.tmp
  "C:\Users\Admin\AppData\Local\Temp\is-9K2R3.tmp\letsvpn3.10.4Install.tmp" /SL5="$4010A,15722891,215552,C:\Users\Admin\AppData\Local\Temp\letsvpn3.10.4Install.exe"
  2⤵
  - Executes dropped EXE
  - Loads dropped DLL
  - System Location Discovery: System Language Discovery
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of FindShellTrayWindow
  - Suspicious use of WriteProcessMemory
  PID:2232
- - C:\Users\Public\Documents\GPUChecker.exe
    "C:\Users\Public\Documents\GPUChecker.exe"
    3⤵
    - UAC bypass
    - Executes dropped EXE
    - Enumerates connected drives
    - Checks processor information in registry
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious behavior: GetForegroundWindowSpam
    - Suspicious use of SetWindowsHookEx
    - System policy modification
    PID:2560
- - C:\Users\Admin\AppData\Local\Temp\is-B0VRF.tmp\letsvpn-3.10.3.exe
    "C:\Users\Admin\AppData\Local\Temp\is-B0VRF.tmp\letsvpn-3.10.3.exe"
    3⤵
    - Executes dropped EXE
    - Loads dropped DLL
    - System Location Discovery: System Language Discovery
    - Suspicious behavior: GetForegroundWindowSpam
    - Suspicious use of WriteProcessMemory
    PID:2892
  - - C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
      powershell.exe -inputformat none -ExecutionPolicy Bypass -Command "If ($env:PROCESSOR_ARCHITEW6432) { $env:PROCESSOR_ARCHITEW6432 } Else { $env:PROCESSOR_ARCHITECTURE }"
      4⤵
      Command and Scripting Interpreter: PowerShell
      System Location Discovery: System Language Discovery
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      PID:2640

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

PowerShell

1

T1059.001

Persistence

Privilege Escalation

Abuse Elevation Control Mechanism

1

T1548

Bypass User Account Control

1

T1548.002

Defense Evasion

Abuse Elevation Control Mechanism

1

T1548

Bypass User Account Control

1

T1548.002

Impair Defenses

1

T1562

Disable or Modify Tools

Modify Registry

Credential Access

Discovery

Peripheral Device Discovery

Query Registry

System Information Discovery

3

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\is-9K2R3.tmp\letsvpn3.10.4Install.tmp

Filesize
921KB

MD5
2a1ea1b44013863f7f1d92ff89f80177

SHA1
66a2f0c14d7692e5cec40ca54b81328519c0f10c

SHA256
c9c04dbc019a9d36fbba1acd0e659eaa13ee7522cc67dd9a82e887abd25b0d4a

SHA512
aef8e28aa281e36801d38883b9af8cfd99b764afd28df9b1f32a9688fe3369bef33af0043fd77c23a8a5a055533d57905f01646db957a6772a972f5148393099

Download Submit
C:\Users\Admin\AppData\Local\Temp\is-B0VRF.tmp\letsvpn-3.10.3.exe

Filesize
14.5MB

MD5
554754b512298e76d45c17de7808e6c2

SHA1
d0b69dd1996cf103a15fee3e0fe1bc1277c7f412

SHA256
aafb3b7ff217393b7b6beba02b3bcee9c076b63bcc78e2cc273c3e6d1092f3c1

SHA512
430c6d9fb4616c506f1d5e510c2b2f4451f86afac43c588956e703565a4404b7a31973b2d0767eb3e27d9e9430da021af90c63dd10750ecc0459950ddf66bd9f

Download Submit
C:\Users\Public\Documents\GPUChecker.exe

Filesize
838KB

MD5
d0e0461bc0a130c622013f61e35aff6d

SHA1
715c1c5f403d7d1a9831be878e1d2a3910bc4f3e

SHA256
d274787942d562893a74ebbfd28285e0c292ba50bed479038c90c0d2d21e368a

SHA512
98d5043162a4e6a6c6a61026c6e5367bf43ad8eba9078e4818697d3aaac4c523f73777ea7cf803a87e81794d13e89ca1a484409c0ab7d9057c4ece43fa13802f

Download Submit
\Users\Admin\AppData\Local\Temp\is-B0VRF.tmp\_isetup\_shfoldr.dll

Filesize
22KB

MD5
92dc6ef532fbb4a5c3201469a5b5eb63

SHA1
3e89ff837147c16b4e41c30d6c796374e0b8e62c

SHA256
9884e9d1b4f8a873ccbd81f8ad0ae257776d2348d027d811a56475e028360d87

SHA512
9908e573921d5dbc3454a1c0a6c969ab8a81cc2e8b5385391d46b1a738fb06a76aa3282e0e58d0d2ffa6f27c85668cd5178e1500b8a39b1bbae04366ae6a86d3

Download Submit
\Users\Admin\AppData\Local\Temp\nsjD5F6.tmp\System.dll

Filesize
11KB

MD5
75ed96254fbf894e42058062b4b4f0d1

SHA1
996503f1383b49021eb3427bc28d13b5bbd11977

SHA256
a632d74332b3f08f834c732a103dafeb09a540823a2217ca7f49159755e8f1d7

SHA512
58174896db81d481947b8745dafe3a02c150f3938bb4543256e8cce1145154e016d481df9fe68dac6d48407c62cbe20753320ebd5fe5e84806d07ce78e0eb0c4

Download Submit
\Users\Admin\AppData\Local\Temp\nsjD5F6.tmp\nsDialogs.dll

Filesize
9KB

MD5
ca95c9da8cef7062813b989ab9486201

SHA1
c555af25df3de51aa18d487d47408d5245dba2d1

SHA256
feb6364375d0ab081e9cdf11271c40cb966af295c600903383b0730f0821c0be

SHA512
a30d94910204d1419c803dc12d90a9d22f63117e4709b1a131d8c4d5ead7e4121150e2c8b004a546b33c40c294df0a74567013001f55f37147d86bb847d7bbc9

Download Submit
\Users\Admin\AppData\Local\Temp\nsjD5F6.tmp\nsExec.dll

Filesize
6KB

MD5
3d366250fcf8b755fce575c75f8c79e4

SHA1
2ebac7df78154738d41aac8e27d7a0e482845c57

SHA256
8bdd996ae4778c6f829e2bcb651c55efc9ec37eeea17d259e013b39528dddbb6

SHA512
67d2d88de625227ccd2cb406b4ac3a215d1770d385c985a44e2285490f49b45f23ce64745b24444e2a0f581335fda02e913b92781043e8dfd287844435ba9094

Download Submit
memory/2232-64-0x0000000000400000-0x00000000004F9000-memory.dmp

Filesize
996KB

Download
memory/2232-11-0x0000000000400000-0x00000000004F9000-memory.dmp

Filesize
996KB

Download
memory/2360-2-0x0000000000401000-0x000000000040B000-memory.dmp

Filesize
40KB

Download
memory/2360-66-0x0000000000400000-0x000000000043C000-memory.dmp

Filesize
240KB

Download
memory/2360-0-0x0000000000400000-0x000000000043C000-memory.dmp

Filesize
240KB

Download
memory/2560-68-0x00000000003D0000-0x00000000003D2000-memory.dmp

Filesize
8KB

Download
memory/2560-69-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download
memory/2560-74-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download
memory/2560-73-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download
memory/2560-72-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download
memory/2560-71-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download
memory/2560-75-0x0000000002240000-0x00000000022AC000-memory.dmp

Filesize
432KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads