Malware Analysis Report

2024-12-07 20:20

Sample ID 241117-l9pd2axerf
Target skuld.exe
SHA256 8e3601302c0294914808b6537cd27de961d087ba0807590b981b7f8c8aa5eee6
Tags
persistence skuld
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK

Enterprise Matrix V15

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral3

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

8e3601302c0294914808b6537cd27de961d087ba0807590b981b7f8c8aa5eee6

Threat Level: Known bad

The file skuld.exe was found to be: Known bad.

Malicious Activity Summary

persistence skuld

Skuld family

Adds Run key to start application

Unsigned PE

Views/modifies file attributes

Suspicious use of AdjustPrivilegeToken

Suspicious use of WriteProcessMemory

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-11-17 10:14

Signatures

Skuld family

skuld

Unsigned PE

Description Indicator Process Target
N/A N/A N/A N/A

Analysis: behavioral1

Detonation Overview

Submitted

2024-11-17 10:14

Reported

2024-11-17 10:18

Platform

win7-20240729-en

Max time kernel

120s

Max time network

125s

Command Line

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

Signatures

N/A

Processes

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

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

Network

N/A

Files

N/A

Analysis: behavioral2

Detonation Overview

Submitted

2024-11-17 10:14

Reported

2024-11-17 10:18

Platform

win10v2004-20241007-en

Max time kernel

96s

Max time network

144s

Command Line

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

Signatures

Adds Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\USER\S-1-5-21-940901362-3608833189-1915618603-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Realtek HD Audio Universal Service = "C:\\Users\\Admin\\AppData\\Roaming\\Microsoft\\Protect\\SecurityHealthSystray.exe" C:\Users\Admin\AppData\Local\Temp\skuld.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 5104 wrote to memory of 4360 N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe C:\Windows\system32\attrib.exe
PID 5104 wrote to memory of 4360 N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe C:\Windows\system32\attrib.exe

Views/modifies file attributes

evasion
Description Indicator Process Target
N/A N/A C:\Windows\system32\attrib.exe N/A

Processes

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

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

C:\Windows\system32\attrib.exe

attrib +h +s C:\Users\Admin\AppData\Local\Temp\skuld.exe

Network

Country Destination Domain Proto
US 8.8.8.8:53 8.8.8.8.in-addr.arpa udp
US 8.8.8.8:53 97.17.167.52.in-addr.arpa udp
US 8.8.8.8:53 88.210.23.2.in-addr.arpa udp
US 8.8.8.8:53 74.32.126.40.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 8.8.8.8:53 133.211.185.52.in-addr.arpa udp
US 8.8.8.8:53 53.210.109.20.in-addr.arpa udp
US 8.8.8.8:53 206.23.85.13.in-addr.arpa udp
US 8.8.8.8:53 217.135.221.88.in-addr.arpa udp
US 8.8.8.8:53 83.210.23.2.in-addr.arpa udp
US 8.8.8.8:53 172.210.232.199.in-addr.arpa udp
US 8.8.8.8:53 22.236.111.52.in-addr.arpa udp

Files

N/A

Analysis: behavioral3

Detonation Overview

Submitted

2024-11-17 10:14

Reported

2024-11-17 10:18

Platform

win11-20241007-en

Max time kernel

146s

Max time network

159s

Command Line

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

Signatures

Adds Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\USER\S-1-5-21-3973800497-2716210218-310192997-1000\Software\Microsoft\Windows\CurrentVersion\Run\Realtek HD Audio Universal Service = "C:\\Users\\Admin\\AppData\\Roaming\\Microsoft\\Protect\\SecurityHealthSystray.exe" C:\Users\Admin\AppData\Local\Temp\skuld.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 788 wrote to memory of 4128 N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe C:\Windows\system32\attrib.exe
PID 788 wrote to memory of 4128 N/A C:\Users\Admin\AppData\Local\Temp\skuld.exe C:\Windows\system32\attrib.exe

Views/modifies file attributes

evasion
Description Indicator Process Target
N/A N/A C:\Windows\system32\attrib.exe N/A

Processes

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

"C:\Users\Admin\AppData\Local\Temp\skuld.exe"

C:\Windows\system32\attrib.exe

attrib +h +s C:\Users\Admin\AppData\Local\Temp\skuld.exe

Network

Country Destination Domain Proto
US 8.8.8.8:53 8.8.8.8.in-addr.arpa udp

Files

N/A