quasar | 40738b4229f48e129ff256c7b37b1005c95647d63b63cc99b59fe75694df314a

General

Target

Client-built.exe
Size

3.1MB
MD5

cb303e914569c62b60c9a5a76bc5541e
SHA1

083465ccd4440106b6c389d566cd027df3ce6229
SHA256

40738b4229f48e129ff256c7b37b1005c95647d63b63cc99b59fe75694df314a
SHA512

546f0c00b09a1f66e6430d9444cfeb4d18a5f58591e5e0170918edb14bfda6ca3d914b21ade2a15788a5662854ebb959aa79f176cf29497e184384781e53b958
SSDEEP

49152:CvyI22SsaNYfdPBldt698dBcjH//j4hKboGddGOTHHB72eh2NT:Cvf22SsaNYfdPBldt6+dBcjHnj4hmt

Score

10^/10

quasar office04 spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

205.234.193.208:4782

Mutex

5b5f36aa-c2fa-4faa-b00e-9ae4a219120b

Attributes

encryption_key
187ACE5C73483AF98BF5C2E3407DF08D3AA8F22B
install_name
Client.exe
log_directory
Logs
reconnect_delay
3000
startup_key
Quasar Client Startup
subdirectory
SubDir

Signatures

Quasar RAT
Quasar is an open source Remote Access Tool.
trojan spyware quasar
Quasar family
quasar

Quasar payload 2 IoCs

resource	yara_rule
behavioral1/memory/4752-1-0x0000000000170000-0x0000000000494000-memory.dmp	family_quasar
behavioral1/files/0x001d00000002ab66-8.dat	family_quasar

Executes dropped EXE 1 IoCs

pid	Process
2420	Client.exe

Modifies registry class 1 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-2584844841-1405471295-1760131749-1000_Classes\Local Settings\MuiCache	MiniSearchHost.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 2 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

T1053.005

pid	Process
2096	schtasks.exe
2416	schtasks.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	4752	Client-built.exe
Token: SeDebugPrivilege	2420	Client.exe

Suspicious use of SetWindowsHookEx 2 IoCs

pid	Process
2420	Client.exe
2216	MiniSearchHost.exe

Suspicious use of WriteProcessMemory 6 IoCs

description	pid	Process	procid_target
PID 4752 wrote to memory of 2096	4752	Client-built.exe	77
PID 4752 wrote to memory of 2096	4752	Client-built.exe	77
PID 4752 wrote to memory of 2420	4752	Client-built.exe	79
PID 4752 wrote to memory of 2420	4752	Client-built.exe	79
PID 2420 wrote to memory of 2416	2420	Client.exe	80
PID 2420 wrote to memory of 2416	2420	Client.exe	80

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\Client-built.exe
"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"
1⤵
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4752
- C:\Windows\SYSTEM32\schtasks.exe
  "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
  2⤵
  - Scheduled Task/Job: Scheduled Task
  PID:2096
- C:\Users\Admin\AppData\Roaming\SubDir\Client.exe
  "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of SetWindowsHookEx
  - Suspicious use of WriteProcessMemory
  PID:2420
- - C:\Windows\SYSTEM32\schtasks.exe
    "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f
    3⤵
    - Scheduled Task/Job: Scheduled Task
    PID:2416

C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe
"C:\Windows\SystemApps\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\MiniSearchHost.exe" -ServerName:MiniSearchUI.AppXj3y73at8fy1htwztzxs68sxx1v7cksp7.mca
1⤵
- Modifies registry class
- Suspicious use of SetWindowsHookEx
PID:2216

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Credential Access

Discovery

Query Registry

1

T1012

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Packages\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\TempState\SearchHoverUnifiedTileModelCache.dat

Filesize
10KB

MD5
71a6b59e08e25451e52675c842fae23c

SHA1
565a97673954a9209c7a05fba20b89d10b88025f

SHA256
5b96212d3d1347b76c8c1c64b2f7ef981242bedd3b84b766b543d56dbbf8dbd6

SHA512
5cc98eb2aa02e2e69165170451d89dd880893e6b07440bb84fbab6cf92cb558bd58c2235d8d64ff43d380c5e9869827800d310ee67950bb21b498d89fbb5aab3

Download Submit
C:\Users\Admin\AppData\Roaming\SubDir\Client.exe

Filesize
3.1MB

MD5
cb303e914569c62b60c9a5a76bc5541e

SHA1
083465ccd4440106b6c389d566cd027df3ce6229

SHA256
40738b4229f48e129ff256c7b37b1005c95647d63b63cc99b59fe75694df314a

SHA512
546f0c00b09a1f66e6430d9444cfeb4d18a5f58591e5e0170918edb14bfda6ca3d914b21ade2a15788a5662854ebb959aa79f176cf29497e184384781e53b958

Download Submit
memory/2420-10-0x00007FFB801F0000-0x00007FFB80CB2000-memory.dmp

Filesize
10.8MB

Download
memory/2420-11-0x00007FFB801F0000-0x00007FFB80CB2000-memory.dmp

Filesize
10.8MB

Download
memory/2420-12-0x000000001C2F0000-0x000000001C340000-memory.dmp

Filesize
320KB

Download
memory/2420-13-0x000000001C400000-0x000000001C4B2000-memory.dmp

Filesize
712KB

Download
memory/2420-14-0x00007FFB801F0000-0x00007FFB80CB2000-memory.dmp

Filesize
10.8MB

Download
memory/2420-15-0x000000001CAF0000-0x000000001D018000-memory.dmp

Filesize
5.2MB

Download
memory/4752-0-0x00007FFB801F3000-0x00007FFB801F5000-memory.dmp

Filesize
8KB

Download
memory/4752-1-0x0000000000170000-0x0000000000494000-memory.dmp

Filesize
3.1MB

Download
memory/4752-2-0x00007FFB801F0000-0x00007FFB80CB2000-memory.dmp

Filesize
10.8MB

Download
memory/4752-9-0x00007FFB801F0000-0x00007FFB80CB2000-memory.dmp

Filesize
10.8MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads