quasar | 31ea3fc3712ff925dc56d07e2cae38724e16acd8c1ac719cb5704b4f40da7e55

General

Target

Client-built(1).exe
Size

3.1MB
MD5

ef3e3811d92c8c39a9dbfa1b3d0dcece
SHA1

8238396252ae7c164c0bca49163040f236fd5148
SHA256

31ea3fc3712ff925dc56d07e2cae38724e16acd8c1ac719cb5704b4f40da7e55
SHA512

f9941d6b7680bac92de5c5af99ccbd4fca77e207330ec918a5a6c4b73a17ae228f4a53a21f33e5491e591ccd970fa0a0a82abacb926c235650c7702555a20a46
SSDEEP

49152:PvjI22SsaNYfdPBldt698dBcjHZGSxNESEjk/iGLoGd6CTHHB72eh2NT:Pvc22SsaNYfdPBldt6+dBcjH9x6I

Score

10^/10

quasar office04 spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

146.0.191.34:4782

Mutex

89ec14d4-c260-40fa-a167-34d2cb269530

Attributes

encryption_key
55CC02601E58E75BE97D8FB498B201E77070B65F
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/2708-1-0x0000000000EB0000-0x00000000011D4000-memory.dmp	family_quasar
behavioral1/files/0x001c00000002aaba-5.dat	family_quasar

Executes dropped EXE 1 IoCs

pid	Process
4664	Client.exe

Drops file in Program Files directory 2 IoCs

description	ioc	Process
File opened for modification	C:\Program Files\SubDir\Client.exe	Client-built(1).exe
File created	C:\Program Files\SubDir\Client.exe	Client-built(1).exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

Modifies registry class 4 IoCs

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-2410826464-2353372766-2364966905-1000_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-1-5-21-2410826464-2353372766-2364966905-1000_Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoftwindows.client.cbs_cw5n1h2txyewy\Internet Settings\Cache\History\CachePrefix = "Visited:"	BackgroundTransferHost.exe
Key created	\REGISTRY\USER\S-1-5-21-2410826464-2353372766-2364966905-1000_Classes\Local Settings\MuiCache	BackgroundTransferHost.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2410826464-2353372766-2364966905-1000_Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoftwindows.client.cbs_cw5n1h2txyewy\Internet Settings\Cache\Content\CachePrefix	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
5112	schtasks.exe
244	schtasks.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2708	Client-built(1).exe
Token: SeDebugPrivilege	4664	Client.exe

Suspicious use of FindShellTrayWindow 1 IoCs

pid	Process
4664	Client.exe

Suspicious use of SendNotifyMessage 1 IoCs

pid	Process
4664	Client.exe

Suspicious use of WriteProcessMemory 6 IoCs

description	pid	Process	procid_target
PID 2708 wrote to memory of 5112	2708	Client-built(1).exe	77
PID 2708 wrote to memory of 5112	2708	Client-built(1).exe	77
PID 2708 wrote to memory of 4664	2708	Client-built(1).exe	79
PID 2708 wrote to memory of 4664	2708	Client-built(1).exe	79
PID 4664 wrote to memory of 244	4664	Client.exe	80
PID 4664 wrote to memory of 244	4664	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(1).exe
"C:\Users\Admin\AppData\Local\Temp\Client-built(1).exe"
1⤵
- Drops file in Program Files directory
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2708
- C:\Windows\SYSTEM32\schtasks.exe
  "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Program Files\SubDir\Client.exe" /rl HIGHEST /f
  2⤵
  - Scheduled Task/Job: Scheduled Task
  PID:5112
- C:\Program Files\SubDir\Client.exe
  "C:\Program Files\SubDir\Client.exe"
  2⤵
  - Executes dropped EXE
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of FindShellTrayWindow
  - Suspicious use of SendNotifyMessage
  - Suspicious use of WriteProcessMemory
  PID:4664
- - C:\Windows\SYSTEM32\schtasks.exe
    "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Program Files\SubDir\Client.exe" /rl HIGHEST /f
    3⤵
    - Scheduled Task/Job: Scheduled Task
    PID:244

C:\Windows\system32\BackgroundTransferHost.exe
"BackgroundTransferHost.exe" -ServerName:BackgroundTransferHost.13
1⤵
- Modifies registry class
PID:2428

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

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Program Files\SubDir\Client.exe

Filesize
3.1MB

MD5
ef3e3811d92c8c39a9dbfa1b3d0dcece

SHA1
8238396252ae7c164c0bca49163040f236fd5148

SHA256
31ea3fc3712ff925dc56d07e2cae38724e16acd8c1ac719cb5704b4f40da7e55

SHA512
f9941d6b7680bac92de5c5af99ccbd4fca77e207330ec918a5a6c4b73a17ae228f4a53a21f33e5491e591ccd970fa0a0a82abacb926c235650c7702555a20a46

Download Submit
C:\Users\Admin\AppData\Local\Packages\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\AC\BackgroundTransferApi\e0ef340d-749e-4a5e-9da9-47b84f9250ab.down_data

Filesize
555KB

MD5
5683c0028832cae4ef93ca39c8ac5029

SHA1
248755e4e1db552e0b6f8651b04ca6d1b31a86fb

SHA256
855abd360d8a8d6974eba92b70cbd09ce519bc8773439993f9ab37cb6847309e

SHA512
aba434bd29be191c823b02ea9b639beb10647bbe7759bbffdaa790dfb1ec2c58d74c525ef11aacda209e4effe322d1d3a07b115446c8914b07a3bce4d8a0e2c3

Download Submit
memory/2708-0-0x00007FF9D2053000-0x00007FF9D2055000-memory.dmp

Filesize
8KB

Download
memory/2708-1-0x0000000000EB0000-0x00000000011D4000-memory.dmp

Filesize
3.1MB

Download
memory/2708-2-0x00007FF9D2050000-0x00007FF9D2B12000-memory.dmp

Filesize
10.8MB

Download
memory/2708-8-0x00007FF9D2050000-0x00007FF9D2B12000-memory.dmp

Filesize
10.8MB

Download
memory/4664-9-0x00007FF9D2050000-0x00007FF9D2B12000-memory.dmp

Filesize
10.8MB

Download
memory/4664-10-0x00007FF9D2050000-0x00007FF9D2B12000-memory.dmp

Filesize
10.8MB

Download
memory/4664-11-0x000000001BFF0000-0x000000001C040000-memory.dmp

Filesize
320KB

Download
memory/4664-12-0x000000001C100000-0x000000001C1B2000-memory.dmp

Filesize
712KB

Download
memory/4664-13-0x00007FF9D2050000-0x00007FF9D2B12000-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