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
Creates scheduled task(s)
Suspicious use of AdjustPrivilegeToken
Suspicious use of SetWindowsHookEx
Uses Task Scheduler COM API
Suspicious use of WriteProcessMemory
MITRE ATT&CK
Enterprise Matrix V15
Analysis: static1
Detonation Overview
Reported
2024-03-31 00:37
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 00:37
Reported
2024-03-31 01:08
Platform
win10-20240221-en
Max time kernel
1798s
Max time network
1800s
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 2660 wrote to memory of 1872 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 2660 wrote to memory of 1872 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 2660 wrote to memory of 2936 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 2660 wrote to memory of 2936 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 2936 wrote to memory of 3440 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 2936 wrote to memory of 3440 | 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 | 240.221.184.93.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 90.57.201.195.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 25.173.189.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 40.134.221.88.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 |
Files
memory/2660-0-0x0000000000D30000-0x0000000001054000-memory.dmp
memory/2660-1-0x00007FF895FF0000-0x00007FF8969DC000-memory.dmp
memory/2660-2-0x000000001BE60000-0x000000001BE70000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/2936-9-0x00007FF895FF0000-0x00007FF8969DC000-memory.dmp
memory/2660-8-0x00007FF895FF0000-0x00007FF8969DC000-memory.dmp
memory/2936-10-0x000000001B6A0000-0x000000001B6B0000-memory.dmp
memory/2936-11-0x000000001BDC0000-0x000000001BE10000-memory.dmp
memory/2936-12-0x000000001BED0000-0x000000001BF82000-memory.dmp
memory/2936-15-0x000000001BE70000-0x000000001BE82000-memory.dmp
memory/2936-16-0x000000001C9C0000-0x000000001C9FE000-memory.dmp
memory/2936-17-0x00007FF895FF0000-0x00007FF8969DC000-memory.dmp
memory/2936-18-0x000000001B6A0000-0x000000001B6B0000-memory.dmp
Analysis: behavioral2
Detonation Overview
Submitted
2024-03-31 00:37
Reported
2024-03-31 01:08
Platform
win10v2004-20240226-en
Max time kernel
1795s
Max time network
1803s
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 4896 wrote to memory of 4908 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4896 wrote to memory of 4908 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4896 wrote to memory of 680 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4896 wrote to memory of 680 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 680 wrote to memory of 1156 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 680 wrote to memory of 1156 | 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
C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --no-appcompat-clear --mojo-platform-channel-handle=1348 --field-trial-handle=2280,i,716736634476467098,11449718822158202904,262144 --variations-seed-version /prefetch:8
C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --no-appcompat-clear --mojo-platform-channel-handle=3784 --field-trial-handle=2280,i,716736634476467098,11449718822158202904,262144 --variations-seed-version /prefetch:8
Network
| Country | Destination | Domain | Proto |
| US | 8.8.8.8:53 | 13.86.106.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 40.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 136.32.126.40.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 | 58.55.71.13.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 196.249.167.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 86.23.85.13.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 206.23.85.13.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 18.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 13.227.111.52.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 41.134.221.88.in-addr.arpa | udp |
| US | 8.8.8.8:53 | 15.173.189.20.in-addr.arpa | udp |
| US | 8.8.8.8:53 | chromewebstore.googleapis.com | udp |
| US | 8.8.8.8:53 | chromewebstore.googleapis.com | udp |
| NL | 216.58.214.10:443 | chromewebstore.googleapis.com | tcp |
| US | 8.8.8.8:53 | 10.214.58.216.in-addr.arpa | udp |
| NL | 52.142.223.178:80 | tcp | |
| US | 8.8.8.8:53 | 114.110.16.96.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 |
Files
memory/4896-0-0x0000000000360000-0x0000000000684000-memory.dmp
memory/4896-1-0x00007FFEAB710000-0x00007FFEAC1D1000-memory.dmp
memory/4896-2-0x000000001B150000-0x000000001B160000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/680-9-0x00007FFEAB710000-0x00007FFEAC1D1000-memory.dmp
memory/680-10-0x0000000001400000-0x0000000001410000-memory.dmp
memory/4896-8-0x00007FFEAB710000-0x00007FFEAC1D1000-memory.dmp
memory/680-11-0x000000001BF90000-0x000000001BFE0000-memory.dmp
memory/680-12-0x000000001C0A0000-0x000000001C152000-memory.dmp
memory/680-15-0x000000001C050000-0x000000001C062000-memory.dmp
memory/680-16-0x000000001CBE0000-0x000000001CC1C000-memory.dmp
memory/680-17-0x00007FFEAB710000-0x00007FFEAC1D1000-memory.dmp
memory/680-18-0x0000000001400000-0x0000000001410000-memory.dmp
Analysis: behavioral3
Detonation Overview
Submitted
2024-03-31 00:37
Reported
2024-03-31 01:08
Platform
win11-20240221-en
Max time kernel
1798s
Max time network
1799s
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 4052 wrote to memory of 4004 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4052 wrote to memory of 4004 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 4052 wrote to memory of 1228 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 4052 wrote to memory of 1228 | N/A | C:\Users\Admin\AppData\Local\Temp\Client-built.exe | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe |
| PID 1228 wrote to memory of 2888 | N/A | C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe | C:\Windows\SYSTEM32\schtasks.exe |
| PID 1228 wrote to memory of 2888 | 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 | 8.8.8.8.in-addr.arpa | udp |
| DE | 195.201.57.90:443 | ipwho.is | 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/4052-0-0x0000000000390000-0x00000000006B4000-memory.dmp
memory/4052-1-0x00007FFE03E70000-0x00007FFE04932000-memory.dmp
memory/4052-2-0x0000000000EC0000-0x0000000000ED0000-memory.dmp
C:\Users\Admin\AppData\Roaming\Windows\WOS64UPD.exe
| MD5 | 57045c2bf3377b12aa5abce21cc0a99d |
| SHA1 | 217202ed404f25fc550ad70fd7066b0fe8773ef9 |
| SHA256 | f2e04196e1353ad216e077e0aeb2e1ab8ee93b8b16b205422b4cc6d8adc50cc2 |
| SHA512 | 9ab46cc194eeaabb75777457a01328f5a8d2ebf604efba0623575cf25c04e206e416ee72db17e3c92a9d363330f82fa3ce2aac64c2a4a61d4dce34d79b73366e |
memory/4052-8-0x00007FFE03E70000-0x00007FFE04932000-memory.dmp
memory/1228-9-0x00007FFE03E70000-0x00007FFE04932000-memory.dmp
memory/1228-10-0x000000001B560000-0x000000001B570000-memory.dmp
memory/1228-11-0x000000001B5C0000-0x000000001B610000-memory.dmp
memory/1228-12-0x000000001BDF0000-0x000000001BEA2000-memory.dmp
memory/1228-15-0x000000001BD50000-0x000000001BD62000-memory.dmp
memory/1228-16-0x000000001BDB0000-0x000000001BDEC000-memory.dmp
memory/1228-17-0x00007FFE03E70000-0x00007FFE04932000-memory.dmp
memory/1228-18-0x000000001B560000-0x000000001B570000-memory.dmp