Analysis
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max time kernel
1793s -
max time network
1792s -
platform
windows10-2004_x64 -
resource
win10v2004-20240226-en -
resource tags
arch:x64arch:x86image:win10v2004-20240226-enlocale:en-usos:windows10-2004-x64system -
submitted
31/03/2024, 00:40
Behavioral task
behavioral1
Sample
Client-built.exe
Resource
win10-20240214-en
Behavioral task
behavioral2
Sample
Client-built.exe
Resource
win10v2004-20240226-en
General
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Target
Client-built.exe
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Size
3.1MB
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MD5
57045c2bf3377b12aa5abce21cc0a99d
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SHA1
217202ed404f25fc550ad70fd7066b0fe8773ef9
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SHA256
f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2
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SHA512
9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e
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SSDEEP
49152:Wv+I22SsaNYfdPBldt698dBcjHukuQPoGdhEQTHHB72eh2NT:Wvz22SsaNYfdPBldt6+dBcjHukuE
Malware Config
Extracted
quasar
1.4.1
Ratted
140.238.91.110:44867
be049c71-d631-4f68-8b3e-8e01081f2340
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encryption_key
AA883CE7347A3543F81EBCDE3BBF3BFC9C60344E
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install_name
WOS64UPD.exe
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log_directory
Windows Update Logs
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reconnect_delay
3000
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startup_key
Windows Updater
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subdirectory
Windows
Signatures
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Quasar payload 2 IoCs
resource yara_rule behavioral2/memory/1916-0-0x0000000000090000-0x00000000003B4000-memory.dmp family_quasar behavioral2/files/0x000a000000023228-5.dat family_quasar -
Executes dropped EXE 1 IoCs
pid Process 1764 WOS64UPD.exe -
Creates scheduled task(s) 1 TTPs 2 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
pid Process 2340 schtasks.exe 1516 schtasks.exe -
Suspicious use of AdjustPrivilegeToken 3 IoCs
description pid Process Token: SeDebugPrivilege 1916 Client-built.exe Token: SeDebugPrivilege 1764 WOS64UPD.exe Token: SeManageVolumePrivilege 2284 svchost.exe -
Suspicious use of SetWindowsHookEx 1 IoCs
pid Process 1764 WOS64UPD.exe -
Suspicious use of WriteProcessMemory 6 IoCs
description pid Process procid_target PID 1916 wrote to memory of 2340 1916 Client-built.exe 89 PID 1916 wrote to memory of 2340 1916 Client-built.exe 89 PID 1916 wrote to memory of 1764 1916 Client-built.exe 91 PID 1916 wrote to memory of 1764 1916 Client-built.exe 91 PID 1764 wrote to memory of 1516 1764 WOS64UPD.exe 92 PID 1764 wrote to memory of 1516 1764 WOS64UPD.exe 92 -
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
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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:1916 -
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)
PID:2340
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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
PID:1764 -
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)
PID:1516
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C:\Windows\system32\rundll32.exe"C:\Windows\system32\rundll32.exe" "C:\Windows\SYSTEM32\EDGEHTML.dll",#141 Microsoft.VCLibs.140.00_8wekyb3d8bbwe1⤵PID:4380
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C:\Windows\System32\svchost.exeC:\Windows\System32\svchost.exe -k UnistackSvcGroup1⤵
- Suspicious use of AdjustPrivilegeToken
PID:2284
Network
MITRE ATT&CK Enterprise v15
Replay Monitor
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Downloads
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Filesize
3.1MB
MD557045c2bf3377b12aa5abce21cc0a99d
SHA1217202ed404f25fc550ad70fd7066b0fe8773ef9
SHA256f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2
SHA5129ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e