quasar | a9e0b5f143ba105d47ce71cc4a3a28efc689415f402620c8f021ca06bf6b5ead

General

Target

ScreenSync.exe
Size

3.1MB
MD5

30fbaed202420d9498bdb13c9693d80e
SHA1

b38397ae8616f9776fb2af4c64691c4b63a26e7b
SHA256

a9e0b5f143ba105d47ce71cc4a3a28efc689415f402620c8f021ca06bf6b5ead
SHA512

9ff1f624174a90b4aeb648f11a92fd3baa5fd1f9c70f6ef5a9c55338fae83d8427206ae514fb9acae0156f1e6dfc2c0472be591ab7ff1fa0a6119edbd55b6f3d
SSDEEP

49152:2vBt62XlaSFNWPjljiFa2RoUYIzp5rbR4jLoGdlTHHB72eh2NT:2vr62XlaSFNWPjljiFXRoUYIzp5mv

Score

10^/10

quasar leo spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Leo

C2

192.168.0.17:4200

Mutex

c93cab56-a846-47c9-8b65-82599c60a04c

Attributes

encryption_key
9D84316EB0C7F33BAF79572A6CB80DCB88C8D3CF
install_name
ScreenSync.exe
log_directory
Logs
reconnect_delay
3000
startup_key
system32.exe
subdirectory
drivers

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/1788-1-0x0000000000470000-0x0000000000794000-memory.dmp	family_quasar
behavioral1/files/0x001c00000002aaba-6.dat	family_quasar

Drops file in Drivers directory 3 IoCs

description	ioc	Process
File created	C:\Windows\system32\drivers\ScreenSync.exe	ScreenSync.exe
File opened for modification	C:\Windows\system32\drivers\ScreenSync.exe	ScreenSync.exe
File opened for modification	C:\Windows\system32\drivers\ScreenSync.exe	ScreenSync.exe

Executes dropped EXE 1 IoCs

pid	Process
716	ScreenSync.exe

Drops file in System32 directory 2 IoCs

description	ioc	Process
File opened for modification	C:\Windows\system32\drivers	ScreenSync.exe
File opened for modification	C:\Windows\system32\drivers	ScreenSync.exe

Modifies registry class 4 IoCs

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-4248760313-3670024077-2384670640-1000_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-1-5-21-4248760313-3670024077-2384670640-1000_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-1-5-21-4248760313-3670024077-2384670640-1000_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-1-5-21-4248760313-3670024077-2384670640-1000_Classes\Local Settings\MuiCache	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
2284	schtasks.exe
1712	schtasks.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	1788	ScreenSync.exe
Token: SeDebugPrivilege	716	ScreenSync.exe

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
716	ScreenSync.exe

Suspicious use of WriteProcessMemory 6 IoCs

description	pid	Process	procid_target
PID 1788 wrote to memory of 2284	1788	ScreenSync.exe	77
PID 1788 wrote to memory of 2284	1788	ScreenSync.exe	77
PID 1788 wrote to memory of 716	1788	ScreenSync.exe	79
PID 1788 wrote to memory of 716	1788	ScreenSync.exe	79
PID 716 wrote to memory of 1712	716	ScreenSync.exe	80
PID 716 wrote to memory of 1712	716	ScreenSync.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\ScreenSync.exe
"C:\Users\Admin\AppData\Local\Temp\ScreenSync.exe"
1⤵
- Drops file in Drivers directory
- Drops file in System32 directory
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1788
- C:\Windows\SYSTEM32\schtasks.exe
  "schtasks" /create /tn "system32.exe" /sc ONLOGON /tr "C:\Windows\system32\drivers\ScreenSync.exe" /rl HIGHEST /f
  2⤵
  - Scheduled Task/Job: Scheduled Task
  PID:2284
- C:\Windows\system32\drivers\ScreenSync.exe
  "C:\Windows\system32\drivers\ScreenSync.exe"
  2⤵
  - Drops file in Drivers directory
  - Executes dropped EXE
  - Drops file in System32 directory
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of SetWindowsHookEx
  - Suspicious use of WriteProcessMemory
  PID:716
- - C:\Windows\SYSTEM32\schtasks.exe
    "schtasks" /create /tn "system32.exe" /sc ONLOGON /tr "C:\Windows\system32\drivers\ScreenSync.exe" /rl HIGHEST /f
    3⤵
    - Scheduled Task/Job: Scheduled Task
    PID:1712

C:\Windows\system32\BackgroundTransferHost.exe
"BackgroundTransferHost.exe" -ServerName:BackgroundTransferHost.13
1⤵
- Modifies registry class
PID:2616

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\Microsoft\CLR_v4.0\UsageLogs\ScreenSync.exe.log

Filesize
1KB

MD5
b4e91d2e5f40d5e2586a86cf3bb4df24

SHA1
31920b3a41aa4400d4a0230a7622848789b38672

SHA256
5d8af3c7519874ed42a0d74ee559ae30d9cc6930aef213079347e2b47092c210

SHA512
968751b79a98961f145de48d425ea820fd1875bae79a725adf35fc8f4706c103ee0c7babd4838166d8a0dda9fbce3728c0265a04c4b37f335ec4eaa110a2b319

Download Submit
C:\Users\Admin\AppData\Local\Packages\MicrosoftWindows.Client.CBS_cw5n1h2txyewy\AC\BackgroundTransferApi\1c631aaa-5dfe-481e-9c75-ca0411d5a31d.down_data

Filesize
555KB

MD5
5683c0028832cae4ef93ca39c8ac5029

SHA1
248755e4e1db552e0b6f8651b04ca6d1b31a86fb

SHA256
855abd360d8a8d6974eba92b70cbd09ce519bc8773439993f9ab37cb6847309e

SHA512
aba434bd29be191c823b02ea9b639beb10647bbe7759bbffdaa790dfb1ec2c58d74c525ef11aacda209e4effe322d1d3a07b115446c8914b07a3bce4d8a0e2c3

Download Submit
C:\Windows\System32\drivers\ScreenSync.exe

Filesize
3.1MB

MD5
30fbaed202420d9498bdb13c9693d80e

SHA1
b38397ae8616f9776fb2af4c64691c4b63a26e7b

SHA256
a9e0b5f143ba105d47ce71cc4a3a28efc689415f402620c8f021ca06bf6b5ead

SHA512
9ff1f624174a90b4aeb648f11a92fd3baa5fd1f9c70f6ef5a9c55338fae83d8427206ae514fb9acae0156f1e6dfc2c0472be591ab7ff1fa0a6119edbd55b6f3d

Download Submit
memory/716-11-0x00007FFE406B0000-0x00007FFE41172000-memory.dmp

Filesize
10.8MB

Download
memory/716-12-0x00007FFE406B0000-0x00007FFE41172000-memory.dmp

Filesize
10.8MB

Download
memory/716-13-0x000000001C460000-0x000000001C4B0000-memory.dmp

Filesize
320KB

Download
memory/716-14-0x000000001C570000-0x000000001C622000-memory.dmp

Filesize
712KB

Download
memory/716-15-0x000000001CD60000-0x000000001D288000-memory.dmp

Filesize
5.2MB

Download
memory/716-16-0x00007FFE406B0000-0x00007FFE41172000-memory.dmp

Filesize
10.8MB

Download
memory/1788-10-0x00007FFE406B0000-0x00007FFE41172000-memory.dmp

Filesize
10.8MB

Download
memory/1788-2-0x00007FFE406B0000-0x00007FFE41172000-memory.dmp

Filesize
10.8MB

Download
memory/1788-0-0x00007FFE406B3000-0x00007FFE406B5000-memory.dmp

Filesize
8KB

Download
memory/1788-1-0x0000000000470000-0x0000000000794000-memory.dmp

Filesize
3.1MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads