quasar | 5fccda50065844a012e1425d3d9d60b608c6d5dc07514d32d04b1c55a1eade36

General

Target

PC_Booster.exe
Size

3.1MB
MD5

81d8571af28e42e2bbe60b5118173da6
SHA1

a826876a268bb7ebcf67b050707ff8a8e05ee6ef
SHA256

5fccda50065844a012e1425d3d9d60b608c6d5dc07514d32d04b1c55a1eade36
SHA512

b6f2dc77b046e4577a996495a6a5589f6ea263e61570ff362f2fb3386dc2b5c80c63ee6ab0678b36e1e11f7a3e46a9c5ed2cf33a5fb523e6afaed0f5a38da347
SSDEEP

49152:KvyI22SsaNYfdPBldt698dBcjHF9rwmCPLoGZB3voTHHB72eh2NT:Kvf22SsaNYfdPBldt6+dBcjHF9rQ

Score

10^/10

quasar office04 spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

192.168.1.18:4782

Mutex

4d099eab-30e3-4c3b-bf50-bf77e2e70e0f

Attributes

encryption_key
04E6B8EB331AA0F74187E430ADEDBC1B79B631E4
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
behavioral2/memory/2376-1-0x0000000000E30000-0x0000000001154000-memory.dmp	family_quasar
behavioral2/files/0x001c00000002aaf4-6.dat	family_quasar

Executes dropped EXE 1 IoCs

pid	Process
4084	Client.exe

Modifies registry class 3 IoCs

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3587106988-279496464-3440778474-1000_Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoftwindows.client.cbs_cw5n1h2txyewy\Internet Settings\Cache\Content\CachePrefix	BackgroundTransferHost.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3587106988-279496464-3440778474-1000_Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoftwindows.client.cbs_cw5n1h2txyewy\Internet Settings\Cache\Cookies\CachePrefix = "Cookie:"	BackgroundTransferHost.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3587106988-279496464-3440778474-1000_Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoftwindows.client.cbs_cw5n1h2txyewy\Internet Settings\Cache\History\CachePrefix = "Visited:"	BackgroundTransferHost.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
3304	schtasks.exe
1956	schtasks.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2376	PC_Booster.exe
Token: SeDebugPrivilege	4084	Client.exe

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
4084	Client.exe

Suspicious use of WriteProcessMemory 6 IoCs

description	pid	Process	procid_target
PID 2376 wrote to memory of 3304	2376	PC_Booster.exe	77
PID 2376 wrote to memory of 3304	2376	PC_Booster.exe	77
PID 2376 wrote to memory of 4084	2376	PC_Booster.exe	79
PID 2376 wrote to memory of 4084	2376	PC_Booster.exe	79
PID 4084 wrote to memory of 1956	4084	Client.exe	80
PID 4084 wrote to memory of 1956	4084	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\PC_Booster.exe
"C:\Users\Admin\AppData\Local\Temp\PC_Booster.exe"
1⤵
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2376
- 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:3304
- 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:4084
- - 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:1956

C:\Windows\system32\BackgroundTransferHost.exe
"BackgroundTransferHost.exe" -ServerName:BackgroundTransferHost.13
1⤵
- Modifies registry class
PID:2424

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\Roaming\SubDir\Client.exe

Filesize
3.1MB

MD5
81d8571af28e42e2bbe60b5118173da6

SHA1
a826876a268bb7ebcf67b050707ff8a8e05ee6ef

SHA256
5fccda50065844a012e1425d3d9d60b608c6d5dc07514d32d04b1c55a1eade36

SHA512
b6f2dc77b046e4577a996495a6a5589f6ea263e61570ff362f2fb3386dc2b5c80c63ee6ab0678b36e1e11f7a3e46a9c5ed2cf33a5fb523e6afaed0f5a38da347

Download Submit
memory/2376-0-0x00007FFE74F73000-0x00007FFE74F75000-memory.dmp

Filesize
8KB

Download
memory/2376-1-0x0000000000E30000-0x0000000001154000-memory.dmp

Filesize
3.1MB

Download
memory/2376-2-0x00007FFE74F70000-0x00007FFE75A32000-memory.dmp

Filesize
10.8MB

Download
memory/2376-9-0x00007FFE74F70000-0x00007FFE75A32000-memory.dmp

Filesize
10.8MB

Download
memory/4084-10-0x00007FFE74F70000-0x00007FFE75A32000-memory.dmp

Filesize
10.8MB

Download
memory/4084-11-0x00007FFE74F70000-0x00007FFE75A32000-memory.dmp

Filesize
10.8MB

Download
memory/4084-12-0x00000000030D0000-0x0000000003120000-memory.dmp

Filesize
320KB

Download
memory/4084-13-0x000000001C2F0000-0x000000001C3A2000-memory.dmp

Filesize
712KB

Download
memory/4084-14-0x00007FFE74F70000-0x00007FFE75A32000-memory.dmp

Filesize
10.8MB

Download
memory/4084-15-0x000000001C9E0000-0x000000001CF08000-memory.dmp

Filesize
5.2MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads