quasar | dbb17bdad394245516b31e3e286453bc7e3de9d6788627fd8970dd588f81f063

General

Target

Clientbuilt.exe
Size

3.1MB
MD5

266ea912a1c1d768a3e2268ee212e79b
SHA1

741ab991660b5568ea0108e6b0e0784c67f1fc17
SHA256

dbb17bdad394245516b31e3e286453bc7e3de9d6788627fd8970dd588f81f063
SHA512

755ad73b05ea6a33e6bfbc0da8482030c2a12e86b751dd9bfe80c7afee097074061a9bb7a73b04a646d1fb3a41e2255abb78d2fbed9a79a3fec9cc30eeae7ae2
SSDEEP

49152:mvflL26AaNeWgPhlmVqvMQ7XSKqTRJ6kbR3LoGdImTHHB72eh2NT:mvtL26AaNeWgPhlmVqkQ7XSKqTRJ6u

Score

10^/10

quasar office04 spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

192.168.1.227:4782

Mutex

f3d13830-043f-4b71-9ea6-e9606fbe9c47

Attributes

encryption_key
E5250226804167CB0B1B4B0E9667D0C056694DCA
install_name
defenderx64.exe
log_directory
Logs
reconnect_delay
3000
startup_key
Windows Defender Helper
subdirectory
Windows Defender

Signatures

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

Quasar payload 3 IoCs

Processes:

resource	yara_rule
behavioral1/memory/1936-1-0x00000000008E0000-0x0000000000C04000-memory.dmp	family_quasar
C:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe	family_quasar
behavioral1/memory/2664-9-0x00000000001A0000-0x00000000004C4000-memory.dmp	family_quasar

Executes dropped EXE 1 IoCs

Processes:

defenderx64.exe

pid process

2664 defenderx64.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082
Creates scheduled task(s) 1 TTPs 2 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
persistence

Scheduled Task/Job
T1053

Processes:

schtasks.exeschtasks.exe

pid process

1960 schtasks.exe
2564 schtasks.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

Clientbuilt.exedefenderx64.exe

description pid process

Token: SeDebugPrivilege 1936 Clientbuilt.exe
Token: SeDebugPrivilege 2664 defenderx64.exe
Suspicious use of FindShellTrayWindow 1 IoCs

Processes:

defenderx64.exe

pid process

2664 defenderx64.exe
Suspicious use of SendNotifyMessage 1 IoCs

Processes:

defenderx64.exe

pid process

2664 defenderx64.exe

pid	process
2664	defenderx64.exe

pid	process
1960	schtasks.exe
2564	schtasks.exe

description	pid	process
Token: SeDebugPrivilege	1936	Clientbuilt.exe
Token: SeDebugPrivilege	2664	defenderx64.exe

pid	process
2664	defenderx64.exe

pid	process
2664	defenderx64.exe

Suspicious use of WriteProcessMemory 9 IoCs

Processes:

Clientbuilt.exedefenderx64.exe

description	pid	process	target process
PID 1936 wrote to memory of 1960	1936	Clientbuilt.exe	schtasks.exe
PID 1936 wrote to memory of 1960	1936	Clientbuilt.exe	schtasks.exe
PID 1936 wrote to memory of 1960	1936	Clientbuilt.exe	schtasks.exe
PID 1936 wrote to memory of 2664	1936	Clientbuilt.exe	defenderx64.exe
PID 1936 wrote to memory of 2664	1936	Clientbuilt.exe	defenderx64.exe
PID 1936 wrote to memory of 2664	1936	Clientbuilt.exe	defenderx64.exe
PID 2664 wrote to memory of 2564	2664	defenderx64.exe	schtasks.exe
PID 2664 wrote to memory of 2564	2664	defenderx64.exe	schtasks.exe
PID 2664 wrote to memory of 2564	2664	defenderx64.exe	schtasks.exe

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\Clientbuilt.exe
"C:\Users\Admin\AppData\Local\Temp\Clientbuilt.exe"
1⤵
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1936

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "Windows Defender Helper" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe" /rl HIGHEST /f
2⤵
- Creates scheduled task(s)
PID:1960

C:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe
"C:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe"
2⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of FindShellTrayWindow
- Suspicious use of SendNotifyMessage
- Suspicious use of WriteProcessMemory
PID:2664

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "Windows Defender Helper" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe" /rl HIGHEST /f
3⤵
- Creates scheduled task(s)
PID:2564

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Persistence

Scheduled Task/Job

1

T1053

Privilege Escalation

Scheduled Task/Job

1

T1053

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:\Users\Admin\AppData\Roaming\Windows Defender\defenderx64.exe

Filesize
3.1MB

MD5
266ea912a1c1d768a3e2268ee212e79b

SHA1
741ab991660b5568ea0108e6b0e0784c67f1fc17

SHA256
dbb17bdad394245516b31e3e286453bc7e3de9d6788627fd8970dd588f81f063

SHA512
755ad73b05ea6a33e6bfbc0da8482030c2a12e86b751dd9bfe80c7afee097074061a9bb7a73b04a646d1fb3a41e2255abb78d2fbed9a79a3fec9cc30eeae7ae2

Download Submit
memory/1936-0-0x000007FEF5693000-0x000007FEF5694000-memory.dmp

Filesize
4KB

Download
memory/1936-1-0x00000000008E0000-0x0000000000C04000-memory.dmp

Filesize
3.1MB

Download
memory/1936-2-0x000007FEF5690000-0x000007FEF607C000-memory.dmp

Filesize
9.9MB

Download
memory/1936-8-0x000007FEF5690000-0x000007FEF607C000-memory.dmp

Filesize
9.9MB

Download
memory/2664-7-0x000007FEF5690000-0x000007FEF607C000-memory.dmp

Filesize
9.9MB

Download
memory/2664-9-0x00000000001A0000-0x00000000004C4000-memory.dmp

Filesize
3.1MB

Download
memory/2664-10-0x000007FEF5690000-0x000007FEF607C000-memory.dmp

Filesize
9.9MB

Download
memory/2664-11-0x000007FEF5690000-0x000007FEF607C000-memory.dmp

Filesize
9.9MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads