Analysis Overview
SHA256
f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2
Threat Level: Known bad
The file Client-built.exe was found to be: Known bad.
Malicious Activity Summary
Quasar RAT
Quasar family
Quasar payload
Executes dropped EXE
Unsigned PE
Suspicious use of AdjustPrivilegeToken
Suspicious use of SetWindowsHookEx
Creates scheduled task(s)
Suspicious use of WriteProcessMemory
Uses Task Scheduler COM API
MITRE ATT&CK
Enterprise Matrix V15
Analysis: static1
Detonation Overview
Reported
2024-03-31 00:44
Signatures
Quasar family
Quasar payload
| Description | Indicator | Process | Target |
| N/A | N/A | N/A | N/A |
Unsigned PE
| Description | Indicator | Process | Target |
| N/A | N/A | N/A | N/A |
Analysis: behavioral1
Detonation Overview
Submitted
2024-03-31 00:44
Reported
2024-03-31 00:47
Platform
win10-20240221-en
Max time kernel
73s
Max time network
140s
Command Line
Signatures
Quasar RAT
Quasar payload
| Description | Indicator | Process | Target |
| N/A | N/A | N/A | N/A |
| N/A | N/A | N/A | N/A |
Executes dropped EXE
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Creates scheduled task(s)
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
Suspicious use of AdjustPrivilegeToken
| Description | Indicator | Process | Target |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | N/A |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of SetWindowsHookEx
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of WriteProcessMemory
| Description | Indicator | Process | Target |
| PID 4800 wrote to memory of 3776 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4800 wrote to memory of 3776 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4800 wrote to memory of 4796 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4800 wrote to memory of 4796 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4796 wrote to memory of 948 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4796 wrote to memory of 948 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
Uses Task Scheduler COM API
Processes
C:\Users\Admin\AppData\Local\Temp\Client-built.exe
"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
"C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
Network
| Country | Destination | Domain | Proto |
| US | 8.8.8.8:53 | 81.171.91.138.in-addr.arpa | udp |
| GB | 140.238.91.110:44867 | tcp | |
| US | 8.8.8.8:53 | ipwho.is | udp |
| DE | 195.201.57.90:443 | ipwho.is | tcp |
| US | 8.8.8.8:53 | 110.91.238.140.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 13.227.111.52.in-addr.arpa | udp |
Files
memory/4800-0-0x0000000000E00000-0x0000000001124000-memory.dmp
memory/4800-1-0x00007FFAB9A70000-0x00007FFABA45C000-memory.dmp
memory/4800-2-0x000000001BED0000-0x000000001BEE0000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/4800-8-0x00007FFAB9A70000-0x00007FFABA45C000-memory.dmp
memory/4796-9-0x00007FFAB9A70000-0x00007FFABA45C000-memory.dmp
memory/4796-10-0x00000000023C0000-0x00000000023D0000-memory.dmp
memory/4796-11-0x000000001BAC0000-0x000000001BB10000-memory.dmp
memory/4796-12-0x000000001BBD0000-0x000000001BC82000-memory.dmp
memory/4796-15-0x000000001BB40000-0x000000001BB52000-memory.dmp
memory/4796-16-0x000000001C2C0000-0x000000001C2FE000-memory.dmp
memory/4796-17-0x00007FFAB9A70000-0x00007FFABA45C000-memory.dmp
memory/4796-18-0x00000000023C0000-0x00000000023D0000-memory.dmp
Analysis: behavioral2
Detonation Overview
Submitted
2024-03-31 00:44
Reported
2024-03-31 00:47
Platform
win10v2004-20240226-en
Max time kernel
93s
Max time network
132s
Command Line
Signatures
Quasar RAT
Quasar payload
| Description | Indicator | Process | Target |
| N/A | N/A | N/A | N/A |
| N/A | N/A | N/A | N/A |
Executes dropped EXE
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Creates scheduled task(s)
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
Suspicious use of AdjustPrivilegeToken
| Description | Indicator | Process | Target |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | N/A |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of SetWindowsHookEx
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of WriteProcessMemory
| Description | Indicator | Process | Target |
| PID 3648 wrote to memory of 3740 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 3648 wrote to memory of 3740 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 3648 wrote to memory of 2868 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 3648 wrote to memory of 2868 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 2868 wrote to memory of 1520 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 2868 wrote to memory of 1520 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
Uses Task Scheduler COM API
Processes
C:\Users\Admin\AppData\Local\Temp\Client-built.exe
"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
"C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
Network
| Country | Destination | Domain | Proto |
| US | 8.8.8.8:53 | 209.205.72.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 0.204.248.87.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 4.159.190.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 95.221.229.192.in-addr.arpa | udp |
| GB | 140.238.91.110:44867 | tcp | |
| US | 8.8.8.8:53 | ipwho.is | udp |
| DE | 195.201.57.90:443 | ipwho.is | tcp |
| US | 8.8.8.8:53 | 110.91.238.140.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 97.17.167.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 157.123.68.40.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 15.164.165.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 217.135.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 240.221.184.93.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 19.229.111.52.in-addr.arpa | udp |
Files
memory/3648-0-0x0000000000D30000-0x0000000001054000-memory.dmp
memory/3648-1-0x00007FFE53590000-0x00007FFE54051000-memory.dmp
memory/3648-2-0x000000001BD40000-0x000000001BD50000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/3648-9-0x00007FFE53590000-0x00007FFE54051000-memory.dmp
memory/2868-8-0x00007FFE53590000-0x00007FFE54051000-memory.dmp
memory/2868-10-0x000000001BEA0000-0x000000001BEF0000-memory.dmp
memory/2868-11-0x000000001BFB0000-0x000000001C062000-memory.dmp
memory/2868-14-0x000000001BF70000-0x000000001BF82000-memory.dmp
memory/2868-15-0x000000001CAF0000-0x000000001CB2C000-memory.dmp
memory/2868-16-0x00007FFE53590000-0x00007FFE54051000-memory.dmp
Analysis: behavioral3
Detonation Overview
Submitted
2024-03-31 00:44
Reported
2024-03-31 00:47
Platform
win11-20240221-en
Max time kernel
148s
Max time network
152s
Command Line
Signatures
Quasar RAT
Quasar payload
| Description | Indicator | Process | Target |
| N/A | N/A | N/A | N/A |
| N/A | N/A | N/A | N/A |
Executes dropped EXE
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Creates scheduled task(s)
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
| N/A | N/A | C:\Windows\SYSTEM32\schtasks.exe | N/A |
Suspicious use of AdjustPrivilegeToken
| Description | Indicator | Process | Target |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | N/A |
| Token: SeDebugPrivilege | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of SetWindowsHookEx
| Description | Indicator | Process | Target |
| N/A | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | N/A |
Suspicious use of WriteProcessMemory
| Description | Indicator | Process | Target |
| PID 4140 wrote to memory of 1064 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4140 wrote to memory of 1064 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4140 wrote to memory of 1012 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4140 wrote to memory of 1012 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 1012 wrote to memory of 1516 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1012 wrote to memory of 1516 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
Uses Task Scheduler COM API
Processes
C:\Users\Admin\AppData\Local\Temp\Client-built.exe
"C:\Users\Admin\AppData\Local\Temp\Client-built.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
"C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe"
C:\Windows\SYSTEM32\schtasks.exe
"schtasks" /create /tn "Windows Updater" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe" /rl HIGHEST /f
Network
| Country | Destination | Domain | Proto |
| GB | 140.238.91.110:44867 | tcp | |
| DE | 195.201.57.90:443 | ipwho.is | tcp |
| US | 8.8.8.8:53 | 8.8.8.8.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 240.221.184.93.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
Files
memory/4140-0-0x0000000000AD0000-0x0000000000DF4000-memory.dmp
memory/4140-1-0x00007FFC69050000-0x00007FFC69B12000-memory.dmp
memory/4140-2-0x000000001BB30000-0x000000001BB40000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/1012-9-0x00007FFC69050000-0x00007FFC69B12000-memory.dmp
memory/4140-8-0x00007FFC69050000-0x00007FFC69B12000-memory.dmp
memory/1012-10-0x000000001BA70000-0x000000001BA80000-memory.dmp
memory/1012-11-0x000000001C670000-0x000000001C6C0000-memory.dmp
memory/1012-12-0x000000001C780000-0x000000001C832000-memory.dmp
memory/1012-15-0x000000001C6C0000-0x000000001C6D2000-memory.dmp
memory/1012-16-0x000000001C720000-0x000000001C75C000-memory.dmp
memory/1012-17-0x00007FFC69050000-0x00007FFC69B12000-memory.dmp