umbral | fe9b415107f164c76a286b93f647b0501fb83e4dd7f839ab7fec9639c55084ae

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
behavioral2/memory/2660-53-0x0000000000A50000-0x0000000000A90000-memory.dmp	family_umbral

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

Executes dropped EXE 1 IoCs

pid	Process
1328	stealer.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
4	ip-api.com

Drops file in Windows directory 2 IoCs

description	ioc	Process
File created	C:\Windows\task.exe	stealer.exe
File opened for modification	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
1520	timeout.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
1532	powershell.exe
2352	powershell.exe

Suspicious use of AdjustPrivilegeToken 3 IoCs

description	pid	Process
Token: SeDebugPrivilege	1328	stealer.exe
Token: SeDebugPrivilege	1532	powershell.exe
Token: SeDebugPrivilege	2352	powershell.exe

Suspicious use of WriteProcessMemory 12 IoCs

description	pid	Process	procid_target
PID 2228 wrote to memory of 1680	2228	stealer v2.exe	30
PID 2228 wrote to memory of 1680	2228	stealer v2.exe	30
PID 2228 wrote to memory of 1680	2228	stealer v2.exe	30
PID 1680 wrote to memory of 1328	1680	cmd.exe	32
PID 1680 wrote to memory of 1328	1680	cmd.exe	32
PID 1680 wrote to memory of 1328	1680	cmd.exe	32
PID 1328 wrote to memory of 1532	1328	stealer.exe	33
PID 1328 wrote to memory of 1532	1328	stealer.exe	33
PID 1328 wrote to memory of 1532	1328	stealer.exe	33
PID 1328 wrote to memory of 2352	1328	stealer.exe	35
PID 1328 wrote to memory of 2352	1328	stealer.exe	35
PID 1328 wrote to memory of 2352	1328	stealer.exe	35

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:2228
- C:\Windows\system32\cmd.exe
  cmd /c "stealer.exe"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:1680
- - 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:1328
  - - 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:1532
  - - 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:2352
  - - C:\Windows\system32\cmd.exe
      cmd /c ""C:\Users\Admin\AppData\Local\Temp\tmp8AD2.tmp.bat""
      4⤵
      PID:840
    - - C:\Windows\system32\timeout.exe
        
        timeout 3
        5⤵
        Delays execution with timeout.exe
        
        PID:1520

C:\Windows\system32\taskeng.exe
taskeng.exe {3DABA6DE-CCA5-409B-A169-248EF5BCFB21} S-1-5-21-330940541-141609230-1670313778-1000:KXIPPCKF\Admin:Interactive:[1]
1⤵
PID:1540
- C:\Windows\task.exe
  C:\Windows\task.exe
  2⤵
  PID:2660
- - C:\Windows\system32\schtasks.exe
    schtasks /run /TN Update
    3⤵
    PID:2888

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\Temp\IXP000.TMP\stealer.exe

Filesize
671KB

MD5
bdb421db1041dff30935a0c368f0316e

SHA1
15786e4eb3057abaeab7c2ebbb0e758d9d4c2216

SHA256
ac14f5357b9e35f8e9fccd2727ae133f34acafbd442cdb6f438a6f7a70861ca2

SHA512
0280a8eeb333437c2122b8e47414565bd8492fee285071e612fc09bb82591a56abd5bf4ed1b194f581656ad1f75727b5c51a6ae50f08d7ea7588c36daa9e6b59

Download Submit
C:\Users\Admin\AppData\Local\Temp\tmp8AD2.tmp.bat

Filesize
170B

MD5
8896799bd3ef5c639b9ef11c05c38066

SHA1
8915d6ff3dc86f4fe90430672fef753a5cd7e8bb

SHA256
88628c0a389f61bb3f2f443a438abb7b87a054cac29502c5bf804047217632a9

SHA512
a1c8879ec7b7cd5250a031697922f3f06045e1fabc4a031b5a4ad2b33cf3280899f78442943366a7c851cd20ccb103aaf01840a9c2fbcc8d13110506eb8485a7

Download Submit
C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Recent\CustomDestinations\590aee7bdd69b59b.customDestinations-ms

Filesize
7KB

MD5
6223fefd955979117628648d2f0d0a2b

SHA1
53264fecf8f70be00690458ec9873a3c005b5585

SHA256
1aeb1b2e4151ce7febd0957877ce6c8f2c266291dd7d5da73797450afe64a42b

SHA512
22a2e89cbd2e2ded4575163deca0d7caf42eaf9d2a630e5190ba733ef5d1f231bb24bb1ed8b4e802cbcc0f8acc2d5fc1d34c46ce4d65ce2bb9a71862b2755aff

Download Submit
memory/1328-6-0x000007FEF64E0000-0x000007FEF6ECC000-memory.dmp

Filesize
9.9MB

Download
memory/1328-5-0x0000000000DA0000-0x0000000000E4E000-memory.dmp

Filesize
696KB

Download
memory/1328-45-0x000007FEF64E0000-0x000007FEF6ECC000-memory.dmp

Filesize
9.9MB

Download
memory/1328-7-0x000000001B2C0000-0x000000001B340000-memory.dmp

Filesize
512KB

Download
memory/1532-16-0x000007FEEE000000-0x000007FEEE99D000-memory.dmp

Filesize
9.6MB

Download
memory/1532-15-0x0000000002720000-0x00000000027A0000-memory.dmp

Filesize
512KB

Download
memory/1532-17-0x0000000002720000-0x00000000027A0000-memory.dmp

Filesize
512KB

Download
memory/1532-18-0x0000000002720000-0x00000000027A0000-memory.dmp

Filesize
512KB

Download
memory/1532-19-0x0000000002720000-0x00000000027A0000-memory.dmp

Filesize
512KB

Download
memory/1532-20-0x000007FEEE000000-0x000007FEEE99D000-memory.dmp

Filesize
9.6MB

Download
memory/1532-14-0x000007FEEE000000-0x000007FEEE99D000-memory.dmp

Filesize
9.6MB

Download
memory/1532-13-0x0000000001F50000-0x0000000001F58000-memory.dmp

Filesize
32KB

Download
memory/1532-12-0x000000001B150000-0x000000001B432000-memory.dmp

Filesize
2.9MB

Download
memory/2352-26-0x000000001B240000-0x000000001B522000-memory.dmp

Filesize
2.9MB

Download
memory/2352-29-0x0000000002790000-0x0000000002810000-memory.dmp

Filesize
512KB

Download
memory/2352-30-0x000007FEED660000-0x000007FEEDFFD000-memory.dmp

Filesize
9.6MB

Download
memory/2352-31-0x0000000002790000-0x0000000002810000-memory.dmp

Filesize
512KB

Download
memory/2352-32-0x0000000002790000-0x0000000002810000-memory.dmp

Filesize
512KB

Download
memory/2352-33-0x0000000002790000-0x0000000002810000-memory.dmp

Filesize
512KB

Download
memory/2352-34-0x000007FEED660000-0x000007FEEDFFD000-memory.dmp

Filesize
9.6MB

Download
memory/2352-27-0x000007FEED660000-0x000007FEEDFFD000-memory.dmp

Filesize
9.6MB

Download
memory/2352-28-0x0000000001FA0000-0x0000000001FA8000-memory.dmp

Filesize
32KB

Download
memory/2660-49-0x000007FEF5AF0000-0x000007FEF64DC000-memory.dmp

Filesize
9.9MB

Download
memory/2660-50-0x0000000000CA0000-0x0000000000D4E000-memory.dmp

Filesize
696KB

Download
memory/2660-51-0x0000000000A90000-0x0000000000B10000-memory.dmp

Filesize
512KB

Download
memory/2660-53-0x0000000000A50000-0x0000000000A90000-memory.dmp

Filesize
256KB

Download
memory/2660-52-0x000000001A790000-0x000000001A7D4000-memory.dmp

Filesize
272KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads