Malware Analysis Report

2025-01-18 04:31

Sample ID 231227-2s588abgb6
Target Client-built.exe
SHA256 37d30f9f28f61ffeb1a8f041167966dc075c62b123d832e738548cd4909d54fd
Tags
office04 quasar spyware trojan
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 Overview

score
10/10

SHA256

37d30f9f28f61ffeb1a8f041167966dc075c62b123d832e738548cd4909d54fd

Threat Level: Known bad

The file Client-built.exe was found to be: Known bad.

Malicious Activity Summary

office04 quasar spyware trojan

Quasar family

Quasar RAT

Quasar payload

Unsigned PE

Modifies registry class

Suspicious use of SetWindowsHookEx

Creates scheduled task(s)

Suspicious use of WriteProcessMemory

Uses Task Scheduler COM API

Suspicious use of AdjustPrivilegeToken

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2023-12-27 22:51

Signatures

Quasar family

quasar

Quasar payload

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

Unsigned PE

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

Analysis: behavioral1

Detonation Overview

Submitted

2023-12-27 22:51

Reported

2023-12-27 22:54

Platform

win11-20231215-en

Max time kernel

145s

Max time network

162s

Command Line

"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"

Signatures

Quasar RAT

trojan spyware quasar

Quasar payload

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

Creates scheduled task(s)

persistence
Description Indicator Process Target
N/A N/A C:\Windows\SYSTEM32\schtasks.exe N/A

Modifies registry class

Description Indicator Process Target
Key created \REGISTRY\USER\S-1-5-21-175642277-3213633112-3688900201-1000_Classes\Local Settings\MuiCache C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe N/A

Suspicious use of AdjustPrivilegeToken

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

Suspicious use of SetWindowsHookEx

Description Indicator Process Target
N/A N/A C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 1828 wrote to memory of 4740 N/A C:\Users\Admin\AppData\Local\Temp\Client-built.exe C:\Windows\SYSTEM32\schtasks.exe
PID 1828 wrote to memory of 4740 N/A C:\Users\Admin\AppData\Local\Temp\Client-built.exe C:\Windows\SYSTEM32\schtasks.exe

Uses Task Scheduler COM API

persistence

Processes

C:\Users\Admin\AppData\Local\Temp\Client-built.exe

"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"

C:\Windows\SYSTEM32\schtasks.exe

"schtasks" /create /tn "Realtek HD Audio Universal Service" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Realtek HD Audio Universal Service\RtkAudUService64.exe" /rl HIGHEST /f

C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe

"C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe" -ServerName:MiniSearchUI.AppXj3y73at8fy1htwztzxs68sxx1v7cksp7.mca

C:\Windows\System32\rundll32.exe

C:\Windows\System32\rundll32.exe C:\Windows\System32\shell32.dll,SHCreateLocalServerRunDll {9aa46009-3ce0-458a-a354-715610a075e6} -Embedding

C:\Windows\SysWOW64\DllHost.exe

C:\Windows\SysWOW64\DllHost.exe /Processid:{06622D85-6856-4460-8DE1-A81921B41C4B}

C:\Windows\system32\rundll32.exe

"C:\Windows\system32\rundll32.exe" C:\Windows\system32\shell32.dll,Control_RunDLL C:\Windows\System32\srchadmin.dll ,

C:\Windows\system32\svchost.exe

C:\Windows\system32\svchost.exe -k LocalService -p -s NPSMSvc

Network

Country Destination Domain Proto
GB 184.28.176.106:443 tcp
US 8.8.8.8:53 browser.pipe.aria.microsoft.com udp
US 52.182.143.210:443 browser.pipe.aria.microsoft.com tcp
GB 184.28.176.106:443 tcp
US 8.8.8.8:53 210.143.182.52.in-addr.arpa udp
US 8.8.8.8:53 222.197.79.204.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 92.123.128.194:443 r.bing.com tcp
US 92.123.128.194:443 r.bing.com tcp
US 92.123.128.194:443 r.bing.com tcp
US 92.123.128.194:443 r.bing.com tcp
US 92.123.128.194:443 r.bing.com tcp
US 92.123.128.194:443 r.bing.com tcp
US 150.171.22.254:443 ln-ring.msedge.net tcp
US 13.107.136.254:443 spo-ring.msedge.net tcp
US 13.107.234.254:443 t-s2-ring.msedge.net tcp
US 8.8.8.8:53 arm-ring.msedge.net udp
US 4.150.240.254:443 arm-ring.msedge.net tcp
US 13.107.246.44:443 fp-afd-nocache-ccp.azureedge.net tcp
US 8.8.8.8:53 81b37932a76a1b8b936ab503c8445000.azr.footprintdns.com udp
AE 20.74.236.255:443 81b37932a76a1b8b936ab503c8445000.azr.footprintdns.com tcp

Files

memory/1828-0-0x00007FFC9EFE0000-0x00007FFC9FAA2000-memory.dmp

memory/1828-1-0x0000000000880000-0x0000000000BA4000-memory.dmp

memory/1828-2-0x000000001B9F0000-0x000000001BA00000-memory.dmp

memory/1828-4-0x00007FFC9EFE0000-0x00007FFC9FAA2000-memory.dmp

memory/1828-5-0x000000001B9F0000-0x000000001BA00000-memory.dmp