Malware Analysis Report

2025-04-13 12:14

Sample ID 240330-dvs5nsgf47
Target Client-abuilt.exe
SHA256 b2ebc3a634719e1727dcae13f9a4f5df3d89b89718cfd0b2886a971a08b55e77
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

b2ebc3a634719e1727dcae13f9a4f5df3d89b89718cfd0b2886a971a08b55e77

Threat Level: Known bad

The file Client-abuilt.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 WriteProcessMemory

Suspicious use of SetWindowsHookEx

Uses Task Scheduler COM API

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-03-30 03:20

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 03:20

Reported

2024-03-30 03:22

Platform

win7-20240221-en

Max time kernel

130s

Max time network

144s

Command Line

"C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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 C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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
File created C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-abuilt.exe N/A
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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-abuilt.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-abuilt.exe

"C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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
N/A 192.168.1.1:4782 tcp
US 198.7.62.204:4782 tcp
N/A 192.168.1.1:4782 tcp
US 198.7.62.204:4782 tcp
N/A 192.168.1.1:4782 tcp

Files

memory/2660-0-0x0000000000360000-0x00000000006A8000-memory.dmp

memory/2660-1-0x000007FEF5810000-0x000007FEF61FC000-memory.dmp

memory/2660-2-0x000000001B2E0000-0x000000001B360000-memory.dmp

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

MD5 fe6bb1f615029c7e339444cbc41706bb
SHA1 cabd13e4e04ef81687812f8680e55e048ee75bd7
SHA256 b2ebc3a634719e1727dcae13f9a4f5df3d89b89718cfd0b2886a971a08b55e77
SHA512 90b15572b73bb065f8cc38a2ca1dbe8ee73991c3693c49f96cda8652d89b010199f4f152b53ae5a7de1a3b13877d301f724ff454e9187950053f7735849e7e82

memory/2680-8-0x000007FEF5810000-0x000007FEF61FC000-memory.dmp

memory/2680-9-0x0000000000CE0000-0x0000000001028000-memory.dmp

memory/2680-10-0x000000001B4A0000-0x000000001B520000-memory.dmp

memory/2660-11-0x000007FEF5810000-0x000007FEF61FC000-memory.dmp

memory/2680-12-0x000007FEF5810000-0x000007FEF61FC000-memory.dmp

memory/2680-13-0x000000001B4A0000-0x000000001B520000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2024-03-30 03:20

Reported

2024-03-30 03:22

Platform

win10v2004-20240226-en

Max time kernel

144s

Max time network

155s

Command Line

"C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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-abuilt.exe N/A
File opened for modification C:\Windows\system32\SubDir\Client.exe C:\Users\Admin\AppData\Local\Temp\Client-abuilt.exe N/A
File opened for modification C:\Windows\system32\SubDir C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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-abuilt.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-abuilt.exe

"C:\Users\Admin\AppData\Local\Temp\Client-abuilt.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=3696 --field-trial-handle=3192,i,2785050981002401924,4037047756083432660,262144 --variations-seed-version /prefetch:8

Network

Country Destination Domain Proto
US 8.8.8.8:53 232.168.11.51.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 0.159.190.20.in-addr.arpa udp
US 8.8.8.8:53 240.221.184.93.in-addr.arpa udp
US 8.8.8.8:53 152.33.115.104.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 8.8.8.8:53 157.123.68.40.in-addr.arpa udp
US 13.107.253.64:443 tcp
N/A 192.168.1.1:4782 tcp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 11.227.111.52.in-addr.arpa udp
N/A 192.168.1.1:4782 tcp
US 8.8.8.8:53 157.123.68.40.in-addr.arpa udp
US 198.7.62.204:4782 tcp
US 8.8.8.8:53 149.220.183.52.in-addr.arpa udp
N/A 192.168.1.1:4782 tcp
US 8.8.8.8:53 26.178.89.13.in-addr.arpa udp

Files

memory/4380-0-0x0000000000010000-0x0000000000358000-memory.dmp

memory/4380-1-0x00007FFED71B0000-0x00007FFED7C71000-memory.dmp

memory/4380-2-0x000000001AF40000-0x000000001AF50000-memory.dmp

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

MD5 fe6bb1f615029c7e339444cbc41706bb
SHA1 cabd13e4e04ef81687812f8680e55e048ee75bd7
SHA256 b2ebc3a634719e1727dcae13f9a4f5df3d89b89718cfd0b2886a971a08b55e77
SHA512 90b15572b73bb065f8cc38a2ca1dbe8ee73991c3693c49f96cda8652d89b010199f4f152b53ae5a7de1a3b13877d301f724ff454e9187950053f7735849e7e82

memory/4084-9-0x00007FFED71B0000-0x00007FFED7C71000-memory.dmp

memory/4084-10-0x000000001B400000-0x000000001B410000-memory.dmp

memory/4380-11-0x00007FFED71B0000-0x00007FFED7C71000-memory.dmp

memory/4084-12-0x000000001C0A0000-0x000000001C0F0000-memory.dmp

memory/4084-13-0x000000001C1B0000-0x000000001C262000-memory.dmp

memory/4084-14-0x00007FFED71B0000-0x00007FFED7C71000-memory.dmp

memory/4084-15-0x000000001B400000-0x000000001B410000-memory.dmp