Analysis Overview
SHA256
f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2
Threat Level: Known bad
The file Client-built.exe was found to be: Known bad.
Malicious Activity Summary
Quasar family
Quasar payload
Quasar RAT
Executes dropped EXE
Unsigned PE
Suspicious use of WriteProcessMemory
Creates scheduled task(s)
Suspicious use of AdjustPrivilegeToken
Uses Task Scheduler COM API
Suspicious use of SetWindowsHookEx
MITRE ATT&CK
Enterprise Matrix V15
Analysis: static1
Detonation Overview
Reported
2024-03-31 00:38
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 00:38
Reported
2024-03-31 01:08
Platform
win10-20240221-en
Max time kernel
1796s
Max time network
1811s
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 4416 wrote to memory of 3924 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4416 wrote to memory of 3924 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4416 wrote to memory of 3112 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4416 wrote to memory of 3112 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 3112 wrote to memory of 4188 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 3112 wrote to memory of 4188 | 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 | |
| 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 | 40.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 21.236.111.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 122.10.44.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 41.134.221.88.in-addr.arpa | udp |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp |
Files
memory/4416-0-0x00000000008E0000-0x0000000000C04000-memory.dmp
memory/4416-1-0x00007FFE53610000-0x00007FFE53FFC000-memory.dmp
memory/4416-2-0x000000001B9B0000-0x000000001B9C0000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/4416-8-0x00007FFE53610000-0x00007FFE53FFC000-memory.dmp
memory/3112-9-0x00007FFE53610000-0x00007FFE53FFC000-memory.dmp
memory/3112-10-0x000000001B3A0000-0x000000001B3B0000-memory.dmp
memory/3112-11-0x000000001BDF0000-0x000000001BE40000-memory.dmp
memory/3112-12-0x000000001BF00000-0x000000001BFB2000-memory.dmp
memory/3112-15-0x000000001B3B0000-0x000000001B3C2000-memory.dmp
memory/3112-16-0x000000001BE80000-0x000000001BEBE000-memory.dmp
memory/3112-17-0x00007FFE53610000-0x00007FFE53FFC000-memory.dmp
memory/3112-18-0x000000001B3A0000-0x000000001B3B0000-memory.dmp
Analysis: behavioral2
Detonation Overview
Submitted
2024-03-31 00:38
Reported
2024-03-31 01:09
Platform
win10v2004-20240226-en
Max time kernel
1803s
Max time network
1816s
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 1620 wrote to memory of 3868 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1620 wrote to memory of 3868 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1620 wrote to memory of 5012 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 1620 wrote to memory of 5012 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 5012 wrote to memory of 4360 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 5012 wrote to memory of 4360 | 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 | 183.142.211.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 41.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 2.159.190.20.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 | 40.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 154.239.44.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 104.219.191.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 26.165.165.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 198.187.3.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 18.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 48.229.111.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 14.179.89.13.in-addr.arpa | udp |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp |
Files
memory/1620-0-0x0000000000280000-0x00000000005A4000-memory.dmp
memory/1620-1-0x00007FFD6ACB0000-0x00007FFD6B771000-memory.dmp
memory/1620-2-0x0000000000E60000-0x0000000000E70000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/5012-8-0x00007FFD6ACB0000-0x00007FFD6B771000-memory.dmp
memory/1620-9-0x00007FFD6ACB0000-0x00007FFD6B771000-memory.dmp
memory/5012-10-0x0000000001490000-0x00000000014A0000-memory.dmp
memory/5012-11-0x000000001C430000-0x000000001C480000-memory.dmp
memory/5012-12-0x000000001C540000-0x000000001C5F2000-memory.dmp
memory/5012-15-0x000000001C4A0000-0x000000001C4B2000-memory.dmp
memory/5012-16-0x000000001C500000-0x000000001C53C000-memory.dmp
memory/5012-17-0x00007FFD6ACB0000-0x00007FFD6B771000-memory.dmp
memory/5012-18-0x0000000001490000-0x00000000014A0000-memory.dmp
Analysis: behavioral3
Detonation Overview
Submitted
2024-03-31 00:38
Reported
2024-03-31 01:08
Platform
win11-20240221-en
Max time kernel
1797s
Max time network
1812s
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 1352 wrote to memory of 1236 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1352 wrote to memory of 1236 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1352 wrote to memory of 236 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 1352 wrote to memory of 236 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 236 wrote to memory of 3340 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 236 wrote to memory of 3340 | 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 | 41.134.221.88.in-addr.arpa | udp |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp | |
| GB | 140.238.91.110:44867 | tcp |
Files
memory/1352-0-0x00000000002F0000-0x0000000000614000-memory.dmp
memory/1352-1-0x00007FFDD4470000-0x00007FFDD4F32000-memory.dmp
memory/1352-2-0x000000001B220000-0x000000001B230000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/236-8-0x00007FFDD4470000-0x00007FFDD4F32000-memory.dmp
memory/1352-9-0x00007FFDD4470000-0x00007FFDD4F32000-memory.dmp
memory/236-10-0x000000001B8D0000-0x000000001B8E0000-memory.dmp
memory/236-11-0x000000001BF30000-0x000000001BF80000-memory.dmp
memory/236-12-0x000000001C040000-0x000000001C0F2000-memory.dmp
memory/236-15-0x000000001BFA0000-0x000000001BFB2000-memory.dmp
memory/236-16-0x000000001C000000-0x000000001C03C000-memory.dmp
memory/236-17-0x00007FFDD4470000-0x00007FFDD4F32000-memory.dmp
memory/236-18-0x000000001B8D0000-0x000000001B8E0000-memory.dmp