umbral | fe9b415107f164c76a286b93f647b0501fb83e4dd7f839ab7fec9639c55084ae

Reason

Machine shutdown: "{\"level\":\"info\",\"time\":\"2024-04-22T13:54:05Z\",\"message\":\"Dirty snapshot: /var/lib/sandbox/hatchvm/win11-20240412-en/instance_14-dirty.qcow2\"}"

General

Target

stealer v2.exe
Size

678KB
MD5

942c8ba962017c3f597a54c44c9f57be
SHA1

bc06cee1fc7c218fe0732f6e13c95cb141fd3b2d
SHA256

fe9b415107f164c76a286b93f647b0501fb83e4dd7f839ab7fec9639c55084ae
SHA512

dee865eca7a6a206c1b197e711494118e6fb696ea3497971ea50222550202eb062d30d49f1814c57d80756fc4cb4c340119a65c895acc9f54f6c1c3820517de8
SSDEEP

12288:Riny90J6VGAQWUJFRjynsW+xUid6IeJO70Nv9cpzolz/:RoyJCNJFlysPd6RJOC4zolz/

Score

10^/10

umbral persistence stealer

Malware Config

Extracted

Family

umbral

C2

https://discord.com/api/webhooks/1231373922524598342/SZ4ChwOih600qv0UuiVxKSVU3wzAKLa2uHxdzmR7pdCC3h5QB7aPcVnGRyY3wZSRS0VF

Signatures

Detect Umbral payload 1 IoCs

resource	yara_rule
behavioral5/memory/2604-44-0x000000001B630000-0x000000001B670000-memory.dmp	family_umbral

Umbral
Umbral stealer is an opensource moduler stealer written in C#.
stealer umbral

Executes dropped EXE 2 IoCs

pid	Process
4932	stealer.exe
2604	task.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\Microsoft\Windows\CurrentVersion\RunOnce\wextract_cleanup0 = "rundll32.exe C:\\Windows\\system32\\advpack.dll,DelNodeRunDLL32 \"C:\\Users\\Admin\\AppData\\Local\\Temp\\IXP000.TMP\\\""	stealer v2.exe

Looks up external IP address via web service 1 IoCs

Uses a legitimate IP lookup service to find the infected system's external IP.

flow	ioc
1	ip-api.com

Drops file in Windows directory 2 IoCs

description	ioc	Process
File opened for modification	C:\Windows\task.exe	stealer.exe
File created	C:\Windows\task.exe	stealer.exe

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

System Information Discovery
T1082

Delays execution with timeout.exe 1 IoCs

evasion

pid	Process
3704	timeout.exe

Suspicious behavior: EnumeratesProcesses 4 IoCs

pid	Process
5032	powershell.exe
5032	powershell.exe
4484	powershell.exe
4484	powershell.exe

Suspicious use of AdjustPrivilegeToken 4 IoCs

description	pid	Process
Token: SeDebugPrivilege	4932	stealer.exe
Token: SeDebugPrivilege	5032	powershell.exe
Token: SeDebugPrivilege	4484	powershell.exe
Token: SeDebugPrivilege	2604	task.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 2336 wrote to memory of 1220	2336	stealer v2.exe	78
PID 2336 wrote to memory of 1220	2336	stealer v2.exe	78
PID 1220 wrote to memory of 4932	1220	cmd.exe	80
PID 1220 wrote to memory of 4932	1220	cmd.exe	80
PID 4932 wrote to memory of 5032	4932	stealer.exe	81
PID 4932 wrote to memory of 5032	4932	stealer.exe	81
PID 4932 wrote to memory of 4484	4932	stealer.exe	83
PID 4932 wrote to memory of 4484	4932	stealer.exe	83

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\stealer v2.exe
"C:\Users\Admin\AppData\Local\Temp\stealer v2.exe"
1⤵
- Adds Run key to start application
- Suspicious use of WriteProcessMemory
PID:2336
- C:\Windows\SYSTEM32\cmd.exe
  cmd /c "stealer.exe"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:1220
- - C:\Users\Admin\AppData\Local\Temp\IXP000.TMP\stealer.exe
    stealer.exe
    3⤵
    - Executes dropped EXE
    - Drops file in Windows directory
    - Suspicious use of AdjustPrivilegeToken
    - Suspicious use of WriteProcessMemory
    PID:4932
  - - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath 'C:\Windows\task.exe'
      4⤵
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      PID:5032
  - - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
      "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'task.exe'
      4⤵
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      PID:4484
  - - C:\Windows\system32\cmd.exe
      C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmp496D.tmp.bat""
      4⤵
      PID:1476
    - - C:\Windows\system32\timeout.exe
        
        timeout 3
        5⤵
        Delays execution with timeout.exe
        
        PID:3704

C:\Windows\task.exe
C:\Windows\task.exe
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:2604

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log

Filesize
2KB

MD5
627073ee3ca9676911bee35548eff2b8

SHA1
4c4b68c65e2cab9864b51167d710aa29ebdcff2e

SHA256
85b280a39fc31ba1e15fb06102a05b8405ff3b82feb181d4170f04e466dd647c

SHA512
3c5f6c03e253b83c57e8d6f0334187dbdcdf4fa549eecd36cbc1322dca6d3ca891dc6a019c49ec2eafb88f82d0434299c31e4dfaab123acb42e0546218f311fb

Download Submit
C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

Filesize
944B

MD5
2e8eb51096d6f6781456fef7df731d97

SHA1
ec2aaf851a618fb43c3d040a13a71997c25bda43

SHA256
96bfd9dd5883329927fe8c08b8956355a1a6ceb30ceeb5d4252b346df32bc864

SHA512
0a73dc9a49f92d9dd556c2ca2e36761890b3538f355ee1f013e7cf648d8c4d065f28046cd4a167db3dea304d1fbcbcea68d11ce6e12a3f20f8b6c018a60422d2

Download Submit
C:\Users\Admin\AppData\Local\Temp\IXP000.TMP\stealer.exe

Filesize
671KB

MD5
bdb421db1041dff30935a0c368f0316e

SHA1
15786e4eb3057abaeab7c2ebbb0e758d9d4c2216

SHA256
ac14f5357b9e35f8e9fccd2727ae133f34acafbd442cdb6f438a6f7a70861ca2

SHA512
0280a8eeb333437c2122b8e47414565bd8492fee285071e612fc09bb82591a56abd5bf4ed1b194f581656ad1f75727b5c51a6ae50f08d7ea7588c36daa9e6b59

Download Submit
C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_z1oubbp1.2kb.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
C:\Users\Admin\AppData\Local\Temp\tmp496D.tmp.bat

Filesize
170B

MD5
490408960280e2bb462e23aa5fa7124b

SHA1
8876a6bd76031a249a69deca4855482ae3c922bb

SHA256
53b82bb9788c0c6aa14f08d9fa0ab90624b61f070d62b57d0ec00d33383490d6

SHA512
27120414f90006f5df8d766bd9623b7ee369c60578c98f657c66984662c1131da695695d2bfaf9401ab6819e95268e51a73bedee1514d263e2ecb3f8ed153897

Download Submit
memory/2604-50-0x00000000011C0000-0x00000000011D0000-memory.dmp

Filesize
64KB

Download
memory/2604-49-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/2604-45-0x000000001B770000-0x000000001B7B4000-memory.dmp

Filesize
272KB

Download
memory/2604-44-0x000000001B630000-0x000000001B670000-memory.dmp

Filesize
256KB

Download
memory/4484-33-0x0000023DFF190000-0x0000023DFF1A0000-memory.dmp

Filesize
64KB

Download
memory/4484-32-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/4484-35-0x0000023DFF190000-0x0000023DFF1A0000-memory.dmp

Filesize
64KB

Download
memory/4484-36-0x0000023DFF190000-0x0000023DFF1A0000-memory.dmp

Filesize
64KB

Download
memory/4484-38-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/4932-7-0x000000001BAC0000-0x000000001BAD0000-memory.dmp

Filesize
64KB

Download
memory/4932-5-0x0000000000C30000-0x0000000000CDE000-memory.dmp

Filesize
696KB

Download
memory/4932-52-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/4932-41-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/4932-6-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/5032-15-0x000001E124790000-0x000001E1247B2000-memory.dmp

Filesize
136KB

Download
memory/5032-8-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/5032-9-0x000001E10B860000-0x000001E10B870000-memory.dmp

Filesize
64KB

Download
memory/5032-22-0x00007FFD50BB0000-0x00007FFD51672000-memory.dmp

Filesize
10.8MB

Download
memory/5032-19-0x000001E10B860000-0x000001E10B870000-memory.dmp

Filesize
64KB

Download

Analysis

Sharing

Errors

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads