umbral | b929ede4c76d1db2d2b1698d401d658fbce5e440fd54f4071701aae69ed791e9

Analysis

max time kernel
146s
max time network
139s
platform
windows11-21h2_x64
resource
win11-20240802-en
resource tags

arch:x64arch:x86image:win11-20240802-enlocale:en-usos:windows11-21h2-x64system
submitted
03-10-2024 17:33

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General

Target

RustAnticheat.exe
Size

1.1MB
MD5

84e9631aef9d0342cae8466ed841ca7f
SHA1

fed84e7f25bb9f337a99e820111e87be1de954aa
SHA256

b929ede4c76d1db2d2b1698d401d658fbce5e440fd54f4071701aae69ed791e9
SHA512

9fd3bf2966edb0ae54a9a46ded59fde75e6c7653078a5cac3563333a0f3ee1c197cfd622c2828855aacbc2023ff85f3d37a01dcb360a0b611aa1a43d59cdd36b
SSDEEP

24576:y1zV1C+mn91Bm1uyv43wswHTFZp/qg0GsO0iT7puGB:uh0I0yIYzFZ90Gstw

Score

10^/10

umbral xworm discovery execution persistence rat stealer trojan

Malware Config

Extracted

Family

xworm

web-amend.gl.at.ply.gg:59501

Attributes

Install_directory
%Userprofile%
install_file
USB.exe

Signatures

Detect Umbral payload 2 IoCs

resource	yara_rule
behavioral4/files/0x000200000002aacc-27.dat	family_umbral
behavioral4/memory/2556-35-0x000001FAF9660000-0x000001FAF96A0000-memory.dmp	family_umbral

Detect Xworm Payload 2 IoCs

resource	yara_rule
behavioral4/files/0x000900000002aab8-16.dat	family_xworm
behavioral4/memory/3160-37-0x0000000000950000-0x0000000000968000-memory.dmp	family_xworm

Umbral
Umbral stealer is an opensource moduler stealer written in C#.
stealer umbral
Xworm
Xworm is a remote access trojan written in C#.
trojan rat xworm

Command and Scripting Interpreter: PowerShell 1 TTPs 4 IoCs

Run Powershell to modify Windows Defender settings to add exclusions for file extensions, paths, and processes.

execution

PowerShell

T1059.001

pid	Process
3544	powershell.exe
240	powershell.exe
2772	powershell.exe
680	powershell.exe

Drops startup file 2 IoCs

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

Executes dropped EXE 5 IoCs

pid	Process
1792	Loader (1).exe
3160	RuntimeBroker.exe
2556	Umbral.exe
3012	RuntimeBroker
4668	RuntimeBroker

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\USER\S-1-5-21-4272559161-3282441186-401869126-1000\Software\Microsoft\Windows\CurrentVersion\Run\RuntimeBroker = "C:\\Users\\Admin\\RuntimeBroker"	RuntimeBroker.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

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	Loader (1).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

T1053.005

pid	Process
3588	schtasks.exe

Suspicious behavior: EnumeratesProcesses 9 IoCs

pid	Process
240	powershell.exe
240	powershell.exe
2772	powershell.exe
2772	powershell.exe
680	powershell.exe
680	powershell.exe
3544	powershell.exe
3544	powershell.exe
3160	RuntimeBroker.exe

Suspicious use of AdjustPrivilegeToken 51 IoCs

description	pid	Process
Token: SeDebugPrivilege	2556	Umbral.exe
Token: SeDebugPrivilege	3160	RuntimeBroker.exe
Token: SeIncreaseQuotaPrivilege	2148	wmic.exe
Token: SeSecurityPrivilege	2148	wmic.exe
Token: SeTakeOwnershipPrivilege	2148	wmic.exe
Token: SeLoadDriverPrivilege	2148	wmic.exe
Token: SeSystemProfilePrivilege	2148	wmic.exe
Token: SeSystemtimePrivilege	2148	wmic.exe
Token: SeProfSingleProcessPrivilege	2148	wmic.exe
Token: SeIncBasePriorityPrivilege	2148	wmic.exe
Token: SeCreatePagefilePrivilege	2148	wmic.exe
Token: SeBackupPrivilege	2148	wmic.exe
Token: SeRestorePrivilege	2148	wmic.exe
Token: SeShutdownPrivilege	2148	wmic.exe
Token: SeDebugPrivilege	2148	wmic.exe
Token: SeSystemEnvironmentPrivilege	2148	wmic.exe
Token: SeRemoteShutdownPrivilege	2148	wmic.exe
Token: SeUndockPrivilege	2148	wmic.exe
Token: SeManageVolumePrivilege	2148	wmic.exe
Token: 33	2148	wmic.exe
Token: 34	2148	wmic.exe
Token: 35	2148	wmic.exe
Token: 36	2148	wmic.exe
Token: SeIncreaseQuotaPrivilege	2148	wmic.exe
Token: SeSecurityPrivilege	2148	wmic.exe
Token: SeTakeOwnershipPrivilege	2148	wmic.exe
Token: SeLoadDriverPrivilege	2148	wmic.exe
Token: SeSystemProfilePrivilege	2148	wmic.exe
Token: SeSystemtimePrivilege	2148	wmic.exe
Token: SeProfSingleProcessPrivilege	2148	wmic.exe
Token: SeIncBasePriorityPrivilege	2148	wmic.exe
Token: SeCreatePagefilePrivilege	2148	wmic.exe
Token: SeBackupPrivilege	2148	wmic.exe
Token: SeRestorePrivilege	2148	wmic.exe
Token: SeShutdownPrivilege	2148	wmic.exe
Token: SeDebugPrivilege	2148	wmic.exe
Token: SeSystemEnvironmentPrivilege	2148	wmic.exe
Token: SeRemoteShutdownPrivilege	2148	wmic.exe
Token: SeUndockPrivilege	2148	wmic.exe
Token: SeManageVolumePrivilege	2148	wmic.exe
Token: 33	2148	wmic.exe
Token: 34	2148	wmic.exe
Token: 35	2148	wmic.exe
Token: 36	2148	wmic.exe
Token: SeDebugPrivilege	240	powershell.exe
Token: SeDebugPrivilege	2772	powershell.exe
Token: SeDebugPrivilege	680	powershell.exe
Token: SeDebugPrivilege	3544	powershell.exe
Token: SeDebugPrivilege	3160	RuntimeBroker.exe
Token: SeDebugPrivilege	3012	RuntimeBroker
Token: SeDebugPrivilege	4668	RuntimeBroker

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
3160	RuntimeBroker.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 2572 wrote to memory of 1792	2572	RustAnticheat.exe	78
PID 2572 wrote to memory of 1792	2572	RustAnticheat.exe	78
PID 2572 wrote to memory of 1792	2572	RustAnticheat.exe	78
PID 2572 wrote to memory of 3160	2572	RustAnticheat.exe	79
PID 2572 wrote to memory of 3160	2572	RustAnticheat.exe	79
PID 2572 wrote to memory of 2556	2572	RustAnticheat.exe	80
PID 2572 wrote to memory of 2556	2572	RustAnticheat.exe	80
PID 2556 wrote to memory of 2148	2556	Umbral.exe	81
PID 2556 wrote to memory of 2148	2556	Umbral.exe	81
PID 3160 wrote to memory of 240	3160	RuntimeBroker.exe	85
PID 3160 wrote to memory of 240	3160	RuntimeBroker.exe	85
PID 3160 wrote to memory of 2772	3160	RuntimeBroker.exe	87
PID 3160 wrote to memory of 2772	3160	RuntimeBroker.exe	87
PID 3160 wrote to memory of 680	3160	RuntimeBroker.exe	89
PID 3160 wrote to memory of 680	3160	RuntimeBroker.exe	89
PID 3160 wrote to memory of 3544	3160	RuntimeBroker.exe	91
PID 3160 wrote to memory of 3544	3160	RuntimeBroker.exe	91
PID 3160 wrote to memory of 3588	3160	RuntimeBroker.exe	93
PID 3160 wrote to memory of 3588	3160	RuntimeBroker.exe	93

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\RustAnticheat.exe
"C:\Users\Admin\AppData\Local\Temp\RustAnticheat.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:2572
- C:\Users\Admin\AppData\Roaming\Loader (1).exe
  "C:\Users\Admin\AppData\Roaming\Loader (1).exe"
  2⤵
  - Executes dropped EXE
  - System Location Discovery: System Language Discovery
  PID:1792
- C:\Users\Admin\AppData\Roaming\RuntimeBroker.exe
  "C:\Users\Admin\AppData\Roaming\RuntimeBroker.exe"
  2⤵
  - Drops startup file
  - Executes dropped EXE
  - Adds Run key to start application
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of SetWindowsHookEx
  - Suspicious use of WriteProcessMemory
  PID:3160
- - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath 'C:\Users\Admin\AppData\Roaming\RuntimeBroker.exe'
    3⤵
    - Command and Scripting Interpreter: PowerShell
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:240
- - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'RuntimeBroker.exe'
    3⤵
    - Command and Scripting Interpreter: PowerShell
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:2772
- - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath 'C:\Users\Admin\RuntimeBroker'
    3⤵
    - Command and Scripting Interpreter: PowerShell
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:680
- - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'RuntimeBroker'
    3⤵
    - Command and Scripting Interpreter: PowerShell
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:3544
- - C:\Windows\System32\schtasks.exe
    "C:\Windows\System32\schtasks.exe" /create /f /RL HIGHEST /sc minute /mo 1 /tn "RuntimeBroker" /tr "C:\Users\Admin\RuntimeBroker"
    3⤵
    - Scheduled Task/Job: Scheduled Task
    PID:3588
- C:\Users\Admin\AppData\Roaming\Umbral.exe
  "C:\Users\Admin\AppData\Roaming\Umbral.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:2556
- - C:\Windows\System32\Wbem\wmic.exe
    "wmic.exe" csproduct get uuid
    3⤵
    - Suspicious use of AdjustPrivilegeToken
    PID:2148

C:\Users\Admin\RuntimeBroker
C:\Users\Admin\RuntimeBroker
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:3012

C:\Users\Admin\RuntimeBroker
C:\Users\Admin\RuntimeBroker
1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:4668

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

T1053.005

Persistence

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Privilege Escalation

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Defense Evasion

Modify Registry

T1112

Credential Access

Discovery

Query Registry

T1012

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\Microsoft\CLR_v4.0\UsageLogs\RuntimeBroker.log

Filesize
654B

MD5
2cbbb74b7da1f720b48ed31085cbd5b8

SHA1
79caa9a3ea8abe1b9c4326c3633da64a5f724964

SHA256
e31b18f21621d9983bfdf1ea3e53884a9d58b8ffd79e0e5790da6f3a81a8b9d3

SHA512
ecf02d5240e0c1c005d3ab393aa7eff62bd498c2db5905157e2bf6d29e1b663228a9583950842629d1a4caef404c8941a0c7799b1a3bd1eb890a09fdb7efcff9

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

Filesize
2KB

MD5
98792f2d1b3d638630fa601df6823aed

SHA1
ee50e507b28f67314752754cce5b2fd3fe739241

SHA256
3f63c900813de99733f162952bb27d374ba2e07d7751965b4de4a557cb4478ce

SHA512
b06c3057f15b00d4d04ac35943e9c2fd44031a72043b79131b0c6a7617ad9c4f2480633bd78ba8d3be61899b5182d2cab6889c0a82e17e9b8a363efed4b69f4b

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

Filesize
944B

MD5
5f24976a3abe0bade41ea9d324efb336

SHA1
8f14782dfde9535cc30eef0366832cd1847085d2

SHA256
d2828fd3d6d00828f193b145cef3309f8b35304903653dae567acd1dff912309

SHA512
dad5150864c974f47303d93cc778ebe64d8d334bc9034b1b760845b851ad118b1c01dfd9e6052ab7beb9ba8a927686464d107e402ccebf407d656db3ac1ecf81

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

Filesize
944B

MD5
051a74485331f9d9f5014e58ec71566c

SHA1
4ed0256a84f2e95609a0b4d5c249bca624db8fe4

SHA256
3f67e4ba795fd89d33e9a1fe7547e297a82ae50b8f25eedc2b33a27866b28888

SHA512
1f15fd8ca727b198495ef826002c1cbcc63e98eecb2e92abff48354ae668e6c3aaf9bd3005664967ae75637bacee7e730ce36142483d08ae6a068d9ae3e0e17d

Download Submit
C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_bz0wbhuw.1rt.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
C:\Users\Admin\AppData\Roaming\Loader (1).exe

Filesize
827KB

MD5
eefb801774c5ccb44153268a9357f5f1

SHA1
b1906b22e14edd142c52808ab3e5ba9346b85de5

SHA256
677aeb1981c58cba41a5d53ccbbf5b471e62dc49dc326570767da940560d840d

SHA512
1cf162fe6184d68dca514059d2de1123e80d0faac401765a54224aa5a987c9454bc92263fbec566835aa7b402f1f63ba59bb425ccc139e0a7391e66991f270b7

Download Submit
C:\Users\Admin\AppData\Roaming\RuntimeBroker.exe

Filesize
73KB

MD5
96af510fc9c01219079834a9c95ddb55

SHA1
14f0c50ad5421350c8ca7f6eaeefd6ab5da38a09

SHA256
3718589c2b1ee0e11197034c51383245fd5cee736a4187bc7d4bbc22daeee598

SHA512
0c560efa6d436435bf1aaaa1c0a1d77d68655591368d8010267ca4b5a24e51204e4bdefce1f7adb6e93b6ecc9401c335e63f886dfd12cec93c759727df8d2da2

Download Submit
C:\Users\Admin\AppData\Roaming\Umbral.exe

Filesize
229KB

MD5
471fb39fc8ef1c26c8b6b332531d79c5

SHA1
fba16c9c0de9ea00cebf4f90ab7095fd0e892ef3

SHA256
c672509e54b49ee79d9a61f2e9deb18311427267799fb65523e71cf76e814830

SHA512
a2cd9fc672ef6fc904a7f0a3b8affff554c5035363b074df48838a9a5c3e48e880cc97fc0e8cf4bfa68d430fd6b01c273fa7fef07d0f70403a15f47c7169f015

Download Submit
memory/240-54-0x0000023379D10000-0x0000023379D32000-memory.dmp

Filesize
136KB

Download
memory/1792-42-0x00000000083B0000-0x00000000083E8000-memory.dmp

Filesize
224KB

Download
memory/1792-43-0x0000000008370000-0x000000000837E000-memory.dmp

Filesize
56KB

Download
memory/1792-39-0x0000000000350000-0x0000000000426000-memory.dmp

Filesize
856KB

Download
memory/2556-45-0x00007FF9132B0000-0x00007FF913D72000-memory.dmp

Filesize
10.8MB

Download
memory/2556-40-0x00007FF9132B0000-0x00007FF913D72000-memory.dmp

Filesize
10.8MB

Download
memory/2556-35-0x000001FAF9660000-0x000001FAF96A0000-memory.dmp

Filesize
256KB

Download
memory/2572-0-0x00007FF9132B3000-0x00007FF9132B5000-memory.dmp

Filesize
8KB

Download
memory/2572-1-0x00000000003E0000-0x0000000000504000-memory.dmp

Filesize
1.1MB

Download
memory/3160-38-0x00007FF9132B0000-0x00007FF913D72000-memory.dmp

Filesize
10.8MB

Download
memory/3160-37-0x0000000000950000-0x0000000000968000-memory.dmp

Filesize
96KB

Download
memory/3160-91-0x00007FF9132B0000-0x00007FF913D72000-memory.dmp

Filesize
10.8MB

Download