umbral | 4cc1f9f24687b31979df108d1cb40b332b2b867aa004314b3844fc9388051d10

Analysis

max time kernel
122s
max time network
137s
platform
windows7_x64
resource
win7-20241010-en
resource tags

arch:x64arch:x86image:win7-20241010-enlocale:en-usos:windows7-x64system
submitted
07/02/2025, 18:39

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General

Target

krx/krx/KRX Client.exe
Size

13.5MB
MD5

14aa5b66b4eb09f2ec43ab2785353b30
SHA1

13e604b67db06e15a4f6c320fadb653f35d8bd1a
SHA256

83d30f0c1b0fb62ba26d7a2a8ddd0f1d0a355d4011d57c9316fc1fe6fc3e144b
SHA512

ae7b132ae3d91e1f7967fffc52c7b30760d4bf29f7c3c25522c27002399c2de865729e99ce7141baa6355ce6e22141721e733bc1ebdacc840f2d3ad112ead39a
SSDEEP

196608:1aqDXlWLO5Ui4d+fNcCnpVubF7d2vziaM7G9PEozWpLMFhKxY+MyAD0vOLQpMJKu:1a0eO9kh7EzzKOPEoypIFDWY3tKgO4

Score

10^/10

umbral discovery stealer

Malware Config

Extracted

Family

umbral

https://discord.com/api/webhooks/1337020963363225641/h0Ve6Z9WtTbW9d3frLkSaZTzjtjFum8OAq1NnRnHG-Vd0mImdRoT37Xs5_5jhVWlKEdf

Signatures

Detect Umbral payload 2 IoCs

resource	yara_rule
behavioral9/files/0x000c000000012262-4.dat	family_umbral
behavioral9/memory/2500-10-0x0000000000860000-0x00000000008A0000-memory.dmp	family_umbral

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

Executes dropped EXE 2 IoCs

pid	Process
2500	Umbral.exe
2396	KRX Client.exe

Loads dropped DLL 2 IoCs

pid	Process
1796	KRX Client.exe
1796	KRX Client.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
6	ip-api.com

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 1 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	KRX Client.exe

Suspicious use of AdjustPrivilegeToken 41 IoCs

description	pid	Process
Token: SeDebugPrivilege	2500	Umbral.exe
Token: SeIncreaseQuotaPrivilege	2940	wmic.exe
Token: SeSecurityPrivilege	2940	wmic.exe
Token: SeTakeOwnershipPrivilege	2940	wmic.exe
Token: SeLoadDriverPrivilege	2940	wmic.exe
Token: SeSystemProfilePrivilege	2940	wmic.exe
Token: SeSystemtimePrivilege	2940	wmic.exe
Token: SeProfSingleProcessPrivilege	2940	wmic.exe
Token: SeIncBasePriorityPrivilege	2940	wmic.exe
Token: SeCreatePagefilePrivilege	2940	wmic.exe
Token: SeBackupPrivilege	2940	wmic.exe
Token: SeRestorePrivilege	2940	wmic.exe
Token: SeShutdownPrivilege	2940	wmic.exe
Token: SeDebugPrivilege	2940	wmic.exe
Token: SeSystemEnvironmentPrivilege	2940	wmic.exe
Token: SeRemoteShutdownPrivilege	2940	wmic.exe
Token: SeUndockPrivilege	2940	wmic.exe
Token: SeManageVolumePrivilege	2940	wmic.exe
Token: 33	2940	wmic.exe
Token: 34	2940	wmic.exe
Token: 35	2940	wmic.exe
Token: SeIncreaseQuotaPrivilege	2940	wmic.exe
Token: SeSecurityPrivilege	2940	wmic.exe
Token: SeTakeOwnershipPrivilege	2940	wmic.exe
Token: SeLoadDriverPrivilege	2940	wmic.exe
Token: SeSystemProfilePrivilege	2940	wmic.exe
Token: SeSystemtimePrivilege	2940	wmic.exe
Token: SeProfSingleProcessPrivilege	2940	wmic.exe
Token: SeIncBasePriorityPrivilege	2940	wmic.exe
Token: SeCreatePagefilePrivilege	2940	wmic.exe
Token: SeBackupPrivilege	2940	wmic.exe
Token: SeRestorePrivilege	2940	wmic.exe
Token: SeShutdownPrivilege	2940	wmic.exe
Token: SeDebugPrivilege	2940	wmic.exe
Token: SeSystemEnvironmentPrivilege	2940	wmic.exe
Token: SeRemoteShutdownPrivilege	2940	wmic.exe
Token: SeUndockPrivilege	2940	wmic.exe
Token: SeManageVolumePrivilege	2940	wmic.exe
Token: 33	2940	wmic.exe
Token: 34	2940	wmic.exe
Token: 35	2940	wmic.exe

Suspicious use of WriteProcessMemory 11 IoCs

description	pid	Process	procid_target
PID 1796 wrote to memory of 2500	1796	KRX Client.exe	31
PID 1796 wrote to memory of 2500	1796	KRX Client.exe	31
PID 1796 wrote to memory of 2500	1796	KRX Client.exe	31
PID 1796 wrote to memory of 2500	1796	KRX Client.exe	31
PID 1796 wrote to memory of 2396	1796	KRX Client.exe	32
PID 1796 wrote to memory of 2396	1796	KRX Client.exe	32
PID 1796 wrote to memory of 2396	1796	KRX Client.exe	32
PID 1796 wrote to memory of 2396	1796	KRX Client.exe	32
PID 2500 wrote to memory of 2940	2500	Umbral.exe	33
PID 2500 wrote to memory of 2940	2500	Umbral.exe	33
PID 2500 wrote to memory of 2940	2500	Umbral.exe	33

C:\Users\Admin\AppData\Local\Temp\krx\krx\KRX Client.exe
"C:\Users\Admin\AppData\Local\Temp\krx\krx\KRX Client.exe"
1⤵
- Loads dropped DLL
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:1796
- C:\Users\Admin\AppData\Local\Temp\Umbral.exe
  "C:\Users\Admin\AppData\Local\Temp\Umbral.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:2500
- - C:\Windows\System32\Wbem\wmic.exe
    "wmic.exe" csproduct get uuid
    3⤵
    - Suspicious use of AdjustPrivilegeToken
    PID:2940
- C:\Users\Admin\AppData\Local\Temp\KRX Client.exe
  "C:\Users\Admin\AppData\Local\Temp\KRX Client.exe"
  2⤵
  - Executes dropped EXE
  PID:2396

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

System Information Discovery

T1082

System Location Discovery

T1614

System Language Discovery

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\Umbral.exe

Filesize
231KB

MD5
39866481d5925ad5fb5a6c72bc51c3c5

SHA1
6c646ec853a4178e219c73cd1788d3f51623099d

SHA256
38042abd98755c213a6f36e5c79d23e7d09b56495b29daab3e89fcdccde80ad2

SHA512
daca18d9d9132ffe07b142a80148aa98575c72052de8bd18115f85adcac1ed8b6f990a85d3076a9c88e934694ae8ba19b58eb6cf81bc27a3c84480c3e853779d

Download Submit
\Users\Admin\AppData\Local\Temp\KRX Client.exe

Filesize
13.4MB

MD5
7907e9406015ceba49d7f1156f032ac8

SHA1
a8034055f4358c1d687b3c2c70c588f37982fa88

SHA256
fc59d043ebbf8e3225f399030bc6447a0592e992bcb57a08d769c35934335de3

SHA512
bff798c9a2301120c343e7108a857dc2a78e5c18fa5fbc06d71ada65f96adbff3ce47e3ffbf51c13db50f0c09ae6d0bcad4a2abe3911e0bd0b2a1b816c0685a9

Download Submit
memory/1796-18-0x0000000003570000-0x00000000055F6000-memory.dmp

Filesize
32.5MB

Download
memory/2396-15-0x0000000140000000-0x0000000142086000-memory.dmp

Filesize
32.5MB

Download
memory/2500-7-0x000007FEF5653000-0x000007FEF5654000-memory.dmp

Filesize
4KB

Download
memory/2500-10-0x0000000000860000-0x00000000008A0000-memory.dmp

Filesize
256KB

Download
memory/2500-17-0x000007FEF5653000-0x000007FEF5654000-memory.dmp

Filesize
4KB

Download