Analysis
- max time kernel
1726s - max time network
1781s - platform
windows11-21h2_x64 - resource
win11-20240221-en - resource tags
- submitted
31/03/2024, 00:42
General
- Target Client-built.exe
- Size 3.1MB
- Sample240331-a2jyssba75
- SHA256 f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2
Malware Config
Extracted
-
quasar
-
1.4.1
-
Ratted
-
140.238.91.110:44867
-
be049c71-d631-4f68-8b3e-8e01081f2340
-
encryption_key
AA883CE7347A3543F81EBCDE3BBF3BFC9C60344E
-
install_name
WOS64UPD.exe
-
log_directory
Windows Update Logs
-
reconnect_delay
3000
-
startup_key
Windows Updater
-
subdirectory
Windows
Signatures
- Quasar RAT
Quasar is an open source Remote Access Tool.
- Quasar payload 2 IoCs
- Executes dropped EXE 1 IoCs
- Creates scheduled task(s) 1 TTPs 2 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
- Suspicious use of AdjustPrivilegeToken 2 IoCs
- Suspicious use of SetWindowsHookEx 1 IoCs
- Suspicious use of WriteProcessMemory 6 IoCs
- 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
-
C:\Windows\SYSTEM32\schtasks.exe"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f2⤵
- Creates scheduled task(s)
-
-
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"2⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
-
C:\Windows\SYSTEM32\schtasks.exe"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f3⤵
- Creates scheduled task(s)
-
-
Network
MITRE ATT&CK Enterprise v15
Replay Monitor
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Downloads
WOS64UPD.exe
memory/668-8-0x00007FF9D5300000-0x00007FF9D5DC2000-memory.dmp
memory/668-1-0x00007FF9D5300000-0x00007FF9D5DC2000-memory.dmp
memory/668-2-0x000000001B240000-0x000000001B250000-memory.dmp
memory/668-0-0x0000000000410000-0x0000000000734000-memory.dmp
memory/4500-10-0x000000001BCB0000-0x000000001BCC0000-memory.dmp
memory/4500-9-0x00007FF9D5300000-0x00007FF9D5DC2000-memory.dmp
memory/4500-11-0x000000001C900000-0x000000001C950000-memory.dmp
memory/4500-12-0x000000001CA10000-0x000000001CAC2000-memory.dmp
memory/4500-15-0x000000001C980000-0x000000001C992000-memory.dmp
memory/4500-16-0x000000001D220000-0x000000001D25C000-memory.dmp
memory/4500-17-0x00007FF9D5300000-0x00007FF9D5DC2000-memory.dmp
memory/4500-18-0x000000001BCB0000-0x000000001BCC0000-memory.dmp