Analysis
- max time kernel
149s - max time network
150s - platform
windows10-2004_x64 - resource
win10v2004-20260513-en - resource tags
arch:x64arch:x86image:win10v2004-20260513-enlocale:en-usos:windows10-2004-x64systemwindows - submitted
06/08/2026, 02:52
Behavioral task
behavioral1
Sample
Client-built.exe
Resource
win10v2004-20260513-en
11 signatures
150 seconds
General
- Target Client-built.exe
- Size 3.1MB
- Sample260806-dc8gmsfd97
- SHA256 584c9def9725a97449d2e11b04c3cdc5c9343cecfd5e74eeaaf943ed169e4957
- MD5 800be6c4b222b61561621786b8e4eb45
- SHA1 3a8e2e20684384258c71fe80f5006f6dfa4b3c15
- SHA512 81dd203acf3f70ab8d2935909c2af72081d942712ae00847bac10102564e20c0582c7178af0b1b5d5d7e7fabc1924c0ceb26bf5c5779c488e5b18e55c22bd060
- SSDEEP 49152:Xv8G42pda6D+/PjlLOlg6yQipV+D6QbR5LoGxbPTHHB72eh2NT:XvH42pda6D+/PjlLOlZyQipV+D60
- TLSH T168E54A1437F85F23E1BBE27396B0041267F0EC1AB3A3FB5B658167791C93B504941AAB
- MD5 SHA1 SHA512 SSDEEP TLSH
Malware Config
Extracted
Family
-
quasar
Version
-
1.4.1
Botnet
-
Office04
C2
-
77bd.cc:443
-
www.77bd.cc:443
-
77bd.cc:80
-
www.77bd.cc:80
Mutex
-
59a6bcf9-b424-40bf-bde8-960b08fe1306
Attributes
-
encryption_key
ED3227F773701D05083B11A65776F95F93EEEF5E
-
install_name
Client.exe
-
key_salt
bfeb1e56fbcd973bb219022430a57843003d5644d21e62b9d4f180e7e6c33941
-
log_directory
Logs
-
reconnect_delay
3000
-
startup_key
Quasar Client Startup
-
subdirectory
SubDir
Signatures
- Quasar payload 2 IoCs
resource yara_rule behavioral1/memory/3188-0-0x00000000006D0000-0x00000000009F4000-memory.dmp family_quasar behavioral1/files/0x000800000002449b-5.dat family_quasar - Executes dropped EXE 2 IoCs
pid Process 4232 Client.exe 1688 Client.exe - Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).
- Scheduled Task/Job: Scheduled Task 1 TTPs 2 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
pid Process 2448 schtasks.exe 552 schtasks.exe - Suspicious use of AdjustPrivilegeToken 3 IoCs
description pid Process Token: SeDebugPrivilege 3188 Client-built.exe Token: SeDebugPrivilege 4232 Client.exe Token: SeDebugPrivilege 1688 Client.exe - Suspicious use of FindShellTrayWindow 1 IoCs
pid Process 4232 Client.exe - Suspicious use of SendNotifyMessage 1 IoCs
pid Process 4232 Client.exe - Suspicious use of SetWindowsHookEx 1 IoCs
pid Process 4232 Client.exe - Suspicious use of WriteProcessMemory 3 IoCs
description pid Process procid_target PID 3188 wrote to memory of 2448 3188 Client-built.exe 86 PID 3188 wrote to memory of 4232 3188 Client-built.exe 88 PID 4232 wrote to memory of 552 4232 Client.exe 91 - 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.
Processes
-
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:3188 -
C:\Windows\SYSTEM32\schtasks.exe"schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f2⤵
- Scheduled Task/Job: Scheduled Task
PID:2448
-
-
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 FindShellTrayWindow
- Suspicious use of SendNotifyMessage
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:4232 -
C:\Windows\SYSTEM32\schtasks.exe"schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\Client.exe" /rl HIGHEST /f3⤵
- Scheduled Task/Job: Scheduled Task
PID:552
-
-
-
C:\Users\Admin\AppData\Roaming\SubDir\Client.exeC:\Users\Admin\AppData\Roaming\SubDir\Client.exe1⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
PID:1688
Network
MITRE ATT&CK Enterprise v16
Replay Monitor
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Downloads
- Path C:\Users\Admin\AppData\Roaming\SubDir\Client.exe
- Size 3.1MB
- SHA256 584c9def9725a97449d2e11b04c3cdc5c9343cecfd5e74eeaaf943ed169e4957
- MD5 800be6c4b222b61561621786b8e4eb45
- SHA1 3a8e2e20684384258c71fe80f5006f6dfa4b3c15
- SHA512 81dd203acf3f70ab8d2935909c2af72081d942712ae00847bac10102564e20c0582c7178af0b1b5d5d7e7fabc1924c0ceb26bf5c5779c488e5b18e55c22bd060
- SSDEEP 49152:Xv8G42pda6D+/PjlLOlg6yQipV+D6QbR5LoGxbPTHHB72eh2NT:XvH42pda6D+/PjlLOlZyQipV+D60
- TLSH T168E54A1437F85F23E1BBE27396B0041267F0EC1AB3A3FB5B658167791C93B504941AAB
- MD5 SHA1 SHA512 SSDEEP TLSH