Malware Analysis Report

2025-04-13 12:14

Sample ID 240330-drxzfsfh5z
Target Client-built.exe
SHA256 46297c4c0a1e8dcbffcc89326acc44e75720a62569242a804be88ea915fe4c8e
Tags
quasar office01 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: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

46297c4c0a1e8dcbffcc89326acc44e75720a62569242a804be88ea915fe4c8e

Threat Level: Known bad

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

Malicious Activity Summary

quasar office01 spyware trojan

Quasar RAT

Quasar payload

Quasar family

Executes dropped EXE

Drops file in System32 directory

Unsigned PE

Creates scheduled task(s)

Suspicious use of AdjustPrivilegeToken

Suspicious use of SetWindowsHookEx

Suspicious use of WriteProcessMemory

Uses Task Scheduler COM API

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-03-30 03:15

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

2024-03-30 03:15

Reported

2024-03-30 03:19

Platform

win7-20240221-en

Max time kernel

130s

Max time network

144s

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
N/A N/A N/A N/A
N/A N/A N/A N/A

Executes dropped EXE

Description Indicator Process Target
N/A N/A C:\Windows\system32\SubDir\Client.exe N/A

Drops file in System32 directory

Description Indicator Process Target
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Windows\system32\SubDir\Client.exe N/A
File opened for modification C:\Windows\system32\SubDir C:\Windows\system32\SubDir\Client.exe N/A
File created C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A
File opened for modification C:\Windows\system32\SubDir C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A

Creates scheduled task(s)

persistence
Description Indicator Process Target
N/A N/A C:\Windows\system32\schtasks.exe N/A
N/A N/A C:\Windows\system32\schtasks.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
Token: SeDebugPrivilege N/A C:\Windows\system32\SubDir\Client.exe N/A

Suspicious use of SetWindowsHookEx

Description Indicator Process Target
N/A N/A C:\Windows\system32\SubDir\Client.exe N/A

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 "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f

C:\Windows\system32\SubDir\Client.exe

"C:\Windows\system32\SubDir\Client.exe"

C:\Windows\system32\schtasks.exe

"schtasks" /create /tn "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f

Network

Country Destination Domain Proto
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp

Files

memory/2456-0-0x0000000000240000-0x0000000000588000-memory.dmp

memory/2456-1-0x000007FEF6020000-0x000007FEF6A0C000-memory.dmp

memory/2456-2-0x000000001AAE0000-0x000000001AB60000-memory.dmp

C:\Windows\System32\SubDir\Client.exe

MD5 eff096752ef1895d626f570a154c38a2
SHA1 ae2c737e15d12d830220bae198b72717422d70d4
SHA256 46297c4c0a1e8dcbffcc89326acc44e75720a62569242a804be88ea915fe4c8e
SHA512 1c0cba459290f89874adab22697c62d9ebe15f41c68b2efa0d004a9e12b1cd4676480e35a04a3dbe9e4cdec59cbc7a2f1e7b5b30da856bf16052c8f958c8a52d

memory/2576-9-0x00000000003D0000-0x0000000000718000-memory.dmp

memory/2456-8-0x000007FEF6020000-0x000007FEF6A0C000-memory.dmp

memory/2576-11-0x000000001B0A0000-0x000000001B120000-memory.dmp

memory/2576-10-0x000007FEF6020000-0x000007FEF6A0C000-memory.dmp

memory/2576-12-0x000007FEF6020000-0x000007FEF6A0C000-memory.dmp

memory/2576-13-0x000000001B0A0000-0x000000001B120000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2024-03-30 03:15

Reported

2024-03-30 03:19

Platform

win10v2004-20240226-en

Max time kernel

149s

Max time network

157s

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
N/A N/A N/A N/A

Executes dropped EXE

Description Indicator Process Target
N/A N/A C:\Windows\system32\SubDir\Client.exe N/A

Drops file in System32 directory

Description Indicator Process Target
File created C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A
File opened for modification C:\Windows\system32\SubDir C:\Users\Admin\AppData\Local\Temp\Client-built.exe N/A
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Windows\system32\SubDir\Client.exe N/A
File opened for modification C:\Windows\system32\SubDir C:\Windows\system32\SubDir\Client.exe N/A

Creates scheduled task(s)

persistence
Description Indicator Process Target
N/A N/A C:\Windows\SYSTEM32\schtasks.exe N/A
N/A N/A C:\Windows\SYSTEM32\schtasks.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
Token: SeDebugPrivilege N/A C:\Windows\system32\SubDir\Client.exe N/A

Suspicious use of SetWindowsHookEx

Description Indicator Process Target
N/A N/A C:\Windows\system32\SubDir\Client.exe N/A

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 "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f

C:\Windows\system32\SubDir\Client.exe

"C:\Windows\system32\SubDir\Client.exe"

C:\Windows\SYSTEM32\schtasks.exe

"schtasks" /create /tn "Client Startup" /sc ONLOGON /tr "C:\Windows\system32\SubDir\Client.exe" /rl HIGHEST /f

C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe

"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --no-appcompat-clear --mojo-platform-channel-handle=3976 --field-trial-handle=2900,i,14549994492153927475,12895178890800740987,262144 --variations-seed-version /prefetch:8

Network

Country Destination Domain Proto
US 8.8.8.8:53 133.211.185.52.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 134.32.126.40.in-addr.arpa udp
US 20.231.121.79:80 tcp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 241.150.49.20.in-addr.arpa udp
US 8.8.8.8:53 26.165.165.52.in-addr.arpa udp
US 8.8.8.8:53 97.17.167.52.in-addr.arpa udp
US 8.8.8.8:53 15.164.165.52.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 48.229.111.52.in-addr.arpa udp
US 8.8.8.8:53 232.168.11.51.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 2.36.159.162.in-addr.arpa udp
US 8.8.8.8:53 198.187.3.20.in-addr.arpa udp
US 8.8.8.8:53 58.55.71.13.in-addr.arpa udp

Files

memory/5076-0-0x0000000000820000-0x0000000000B68000-memory.dmp

memory/5076-1-0x00007FFE89DA0000-0x00007FFE8A861000-memory.dmp

memory/5076-2-0x000000001B9A0000-0x000000001B9B0000-memory.dmp

C:\Windows\System32\SubDir\Client.exe

MD5 eff096752ef1895d626f570a154c38a2
SHA1 ae2c737e15d12d830220bae198b72717422d70d4
SHA256 46297c4c0a1e8dcbffcc89326acc44e75720a62569242a804be88ea915fe4c8e
SHA512 1c0cba459290f89874adab22697c62d9ebe15f41c68b2efa0d004a9e12b1cd4676480e35a04a3dbe9e4cdec59cbc7a2f1e7b5b30da856bf16052c8f958c8a52d

memory/5076-9-0x00007FFE89DA0000-0x00007FFE8A861000-memory.dmp

memory/2280-10-0x00007FFE89DA0000-0x00007FFE8A861000-memory.dmp

memory/2280-11-0x000000001BE30000-0x000000001BE40000-memory.dmp

memory/2280-12-0x0000000003200000-0x0000000003250000-memory.dmp

memory/2280-13-0x000000001C9F0000-0x000000001CAA2000-memory.dmp

memory/2280-14-0x00007FFE89DA0000-0x00007FFE8A861000-memory.dmp

memory/2280-15-0x000000001BE30000-0x000000001BE40000-memory.dmp