skuld | 774c71f4e65a17cc744e906660435598f9b62dfdd599e9babbed3dd9dea32e53

General

Target

skuld.exe
Size

14.2MB
MD5

3eb420ceca33cebdf59e96abd6ba75a3
SHA1

fbd442d69323445e9ecedbe820c61fbac7fdb287
SHA256

774c71f4e65a17cc744e906660435598f9b62dfdd599e9babbed3dd9dea32e53
SHA512

06047f5492f785bb672c6059ef2b0f31855a63d4e91a41c9e8178d4958c5e50825433a4f8cd87e1aaf4be56492d9f86eccdbe9cf9ed3929621005636f591ee69
SSDEEP

196608:5ADrfDmwoUoG3n5OJG1Nf0k7Ma/rkFlgdTaUrPPbdf5:5A3faw+JG1KkSFCdTauZR

Score

10^/10

skuld persistence stealer

Malware Config

Signatures

Skuld stealer
An info stealer written in Go lang.
stealer skuld

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

Processes:

skuld.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Realtek HD Audio Universal Service = "C:\\Users\\Admin\\AppData\\Roaming\\Microsoft\\Protect\\SecurityHealthSystray.exe"	skuld.exe

Looks up external IP address via web service 3 IoCs
Uses a legitimate IP lookup service to find the infected system's external IP.

Processes:

flow ioc

1 api.ipify.org
2 api.ipify.org
6 ip-api.com
GoLang User-Agent 1 IoCs
Uses default user-agent string defined by GoLang HTTP packages.

Processes:

description flow ioc

HTTP User-Agent header 7 Go-http-client/1.1

flow	ioc
1	api.ipify.org
2	api.ipify.org
6	ip-api.com

description	flow	ioc
HTTP User-Agent header	7	Go-http-client/1.1

Modifies system certificate store 2 TTPs 3 IoCs

evasion spyware trojan

Install Root Certificate

T1553.004

Modify Registry

T1112

Processes:

skuld.exe

description	ioc	process
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\B1BC968BD4F49D622AA89A81F2150152A41D829C	skuld.exe
Set value (data)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\B1BC968BD4F49D622AA89A81F2150152A41D829C\Blob = 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	skuld.exe
Set value (data)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\B1BC968BD4F49D622AA89A81F2150152A41D829C\Blob = 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	skuld.exe

Suspicious use of AdjustPrivilegeToken 43 IoCs

Processes:

skuld.exewmic.exe

description	pid	process
Token: SeDebugPrivilege	5048	skuld.exe
Token: SeIncreaseQuotaPrivilege	4484	wmic.exe
Token: SeSecurityPrivilege	4484	wmic.exe
Token: SeTakeOwnershipPrivilege	4484	wmic.exe
Token: SeLoadDriverPrivilege	4484	wmic.exe
Token: SeSystemProfilePrivilege	4484	wmic.exe
Token: SeSystemtimePrivilege	4484	wmic.exe
Token: SeProfSingleProcessPrivilege	4484	wmic.exe
Token: SeIncBasePriorityPrivilege	4484	wmic.exe
Token: SeCreatePagefilePrivilege	4484	wmic.exe
Token: SeBackupPrivilege	4484	wmic.exe
Token: SeRestorePrivilege	4484	wmic.exe
Token: SeShutdownPrivilege	4484	wmic.exe
Token: SeDebugPrivilege	4484	wmic.exe
Token: SeSystemEnvironmentPrivilege	4484	wmic.exe
Token: SeRemoteShutdownPrivilege	4484	wmic.exe
Token: SeUndockPrivilege	4484	wmic.exe
Token: SeManageVolumePrivilege	4484	wmic.exe
Token: 33	4484	wmic.exe
Token: 34	4484	wmic.exe
Token: 35	4484	wmic.exe
Token: 36	4484	wmic.exe
Token: SeIncreaseQuotaPrivilege	4484	wmic.exe
Token: SeSecurityPrivilege	4484	wmic.exe
Token: SeTakeOwnershipPrivilege	4484	wmic.exe
Token: SeLoadDriverPrivilege	4484	wmic.exe
Token: SeSystemProfilePrivilege	4484	wmic.exe
Token: SeSystemtimePrivilege	4484	wmic.exe
Token: SeProfSingleProcessPrivilege	4484	wmic.exe
Token: SeIncBasePriorityPrivilege	4484	wmic.exe
Token: SeCreatePagefilePrivilege	4484	wmic.exe
Token: SeBackupPrivilege	4484	wmic.exe
Token: SeRestorePrivilege	4484	wmic.exe
Token: SeShutdownPrivilege	4484	wmic.exe
Token: SeDebugPrivilege	4484	wmic.exe
Token: SeSystemEnvironmentPrivilege	4484	wmic.exe
Token: SeRemoteShutdownPrivilege	4484	wmic.exe
Token: SeUndockPrivilege	4484	wmic.exe
Token: SeManageVolumePrivilege	4484	wmic.exe
Token: 33	4484	wmic.exe
Token: 34	4484	wmic.exe
Token: 35	4484	wmic.exe
Token: 36	4484	wmic.exe

Suspicious use of WriteProcessMemory 6 IoCs

Processes:

skuld.exe

description	pid	process	target process
PID 5048 wrote to memory of 1092	5048	skuld.exe	attrib.exe
PID 5048 wrote to memory of 1092	5048	skuld.exe	attrib.exe
PID 5048 wrote to memory of 2156	5048	skuld.exe	attrib.exe
PID 5048 wrote to memory of 2156	5048	skuld.exe	attrib.exe
PID 5048 wrote to memory of 4484	5048	skuld.exe	wmic.exe
PID 5048 wrote to memory of 4484	5048	skuld.exe	wmic.exe

Views/modifies file attributes 1 TTPs 2 IoCs
evasion

Hidden Files and Directories
T1564.001

Processes:

attrib.exeattrib.exe

pid process

1092 attrib.exe
2156 attrib.exe

pid	process
1092	attrib.exe
2156	attrib.exe

C:\Users\Admin\AppData\Local\Temp\skuld.exe
"C:\Users\Admin\AppData\Local\Temp\skuld.exe"
1⤵
- Adds Run key to start application
- Modifies system certificate store
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:5048
- C:\Windows\system32\attrib.exe
  attrib +h +s C:\Users\Admin\AppData\Local\Temp\skuld.exe
  2⤵
  - Views/modifies file attributes
  PID:1092
- C:\Windows\system32\attrib.exe
  attrib +h +s C:\Users\Admin\AppData\Roaming\Microsoft\Protect\SecurityHealthSystray.exe
  2⤵
  - Views/modifies file attributes
  PID:2156
- C:\Windows\System32\Wbem\wmic.exe
  wmic csproduct get UUID
  2⤵
  - Suspicious use of AdjustPrivilegeToken
  PID:4484

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

Hide Artifacts

1

T1564

Hidden Files and Directories

Modify Registry

Subvert Trust Controls

1

T1553

Install Root Certificate

1

T1553.004

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Roaming\Microsoft\Protect\SecurityHealthSystray.exe

Filesize
14.2MB

MD5
3eb420ceca33cebdf59e96abd6ba75a3

SHA1
fbd442d69323445e9ecedbe820c61fbac7fdb287

SHA256
774c71f4e65a17cc744e906660435598f9b62dfdd599e9babbed3dd9dea32e53

SHA512
06047f5492f785bb672c6059ef2b0f31855a63d4e91a41c9e8178d4958c5e50825433a4f8cd87e1aaf4be56492d9f86eccdbe9cf9ed3929621005636f591ee69

Download Submit

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads