remcos | f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39

Modify Registry

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit = "C:\\WINDOWS\\system32\\userinit.exe, \"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit = "C:\\WINDOWS\\system32\\userinit.exe, \"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	Dxpserver.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit = "C:\\WINDOWS\\system32\\userinit.exe, \"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	Dxpserver.exe

Remcos
Remcos is a closed-source remote control and surveillance software.
rat remcos
Remcos family
remcos

Checks computer location settings 2 TTPs 5 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	Dxpserver.exe
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	Dxpserver.exe
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	Dxpserver.exe

Executes dropped EXE 4 IoCs

pid	Process
1788	Dxpserver.exe
1224	Dxpserver.exe
428	Dxpserver.exe
1520	Dxpserver.exe

Adds Run key to start application 2 TTPs 3 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\remcos = "\"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\remcos = "\"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	Dxpserver.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\remcos = "\"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	Dxpserver.exe

Modifies WinLogon 2 TTPs 3 IoCs

persistence

Winlogon Helper DLL

Modify Registry

description	ioc	Process
Key created	\REGISTRY\MACHINE\Software\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\	Dxpserver.exe
Key created	\REGISTRY\MACHINE\Software\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\	Dxpserver.exe
Key created	\REGISTRY\MACHINE\Software\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe

AutoIT Executable 1 IoCs

AutoIT scripts compiled to PE executables.

resource	yara_rule
behavioral2/files/0x000a000000023b94-15.dat	autoit_exe

Suspicious use of SetThreadContext 3 IoCs

description	pid	Process	procid_target
PID 4416 set thread context of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 1788 set thread context of 1224	1788	Dxpserver.exe	96
PID 428 set thread context of 1520	428	Dxpserver.exe	101

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 11 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Dxpserver.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Dxpserver.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Dxpserver.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Dxpserver.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	WScript.exe

Modifies registry class 3 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000_Classes\Local Settings	Dxpserver.exe
Key created	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000_Classes\Local Settings	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
Key created	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000_Classes\Local Settings	Dxpserver.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 2 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

pid	Process
2072	schtasks.exe
2032	schtasks.exe

Suspicious use of WriteProcessMemory 30 IoCs

description	pid	Process	procid_target
PID 4416 wrote to memory of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 4416 wrote to memory of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 4416 wrote to memory of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 4416 wrote to memory of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 4416 wrote to memory of 4872	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	82
PID 4872 wrote to memory of 544	4872	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	83
PID 4872 wrote to memory of 544	4872	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	83
PID 4872 wrote to memory of 544	4872	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	83
PID 4416 wrote to memory of 2072	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	89
PID 4416 wrote to memory of 2072	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	89
PID 4416 wrote to memory of 2072	4416	f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe	89
PID 1788 wrote to memory of 1224	1788	Dxpserver.exe	96
PID 1788 wrote to memory of 1224	1788	Dxpserver.exe	96
PID 1788 wrote to memory of 1224	1788	Dxpserver.exe	96
PID 1788 wrote to memory of 1224	1788	Dxpserver.exe	96
PID 1788 wrote to memory of 1224	1788	Dxpserver.exe	96
PID 1224 wrote to memory of 3716	1224	Dxpserver.exe	97
PID 1224 wrote to memory of 3716	1224	Dxpserver.exe	97
PID 1224 wrote to memory of 3716	1224	Dxpserver.exe	97
PID 1788 wrote to memory of 2032	1788	Dxpserver.exe	98
PID 1788 wrote to memory of 2032	1788	Dxpserver.exe	98
PID 1788 wrote to memory of 2032	1788	Dxpserver.exe	98
PID 428 wrote to memory of 1520	428	Dxpserver.exe	101
PID 428 wrote to memory of 1520	428	Dxpserver.exe	101
PID 428 wrote to memory of 1520	428	Dxpserver.exe	101
PID 428 wrote to memory of 1520	428	Dxpserver.exe	101
PID 428 wrote to memory of 1520	428	Dxpserver.exe	101
PID 1520 wrote to memory of 436	1520	Dxpserver.exe	102
PID 1520 wrote to memory of 436	1520	Dxpserver.exe	102
PID 1520 wrote to memory of 436	1520	Dxpserver.exe	102

C:\Users\Admin\AppData\Local\Temp\f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
"C:\Users\Admin\AppData\Local\Temp\f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe"
1⤵
- Checks computer location settings
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:4416
- C:\Users\Admin\AppData\Local\Temp\f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe
  "C:\Users\Admin\AppData\Local\Temp\f3b4bd01388ef8fa3e63da36192a1b56d027c13df4375986c2f0404e16ab9b39N.exe"
  2⤵
  - Modifies WinLogon for persistence
  - Checks computer location settings
  - Adds Run key to start application
  - Modifies WinLogon
  - System Location Discovery: System Language Discovery
  - Modifies registry class
  - Suspicious use of WriteProcessMemory
  PID:4872
- - C:\Windows\SysWOW64\WScript.exe
    "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\install.vbs"
    3⤵
    - System Location Discovery: System Language Discovery
    PID:544
- C:\Windows\SysWOW64\schtasks.exe
  "C:\Windows\SysWOW64\schtasks.exe" /create /tn cttunesvr /tr "C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe" /sc minute /mo 1 /F
  2⤵
  - System Location Discovery: System Language Discovery
  - Scheduled Task/Job: Scheduled Task
  PID:2072

C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
1⤵
- Checks computer location settings
- Executes dropped EXE
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:1788
- C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
  "C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe"
  2⤵
  - Modifies WinLogon for persistence
  - Checks computer location settings
  - Executes dropped EXE
  - Adds Run key to start application
  - Modifies WinLogon
  - System Location Discovery: System Language Discovery
  - Modifies registry class
  - Suspicious use of WriteProcessMemory
  PID:1224
- - C:\Windows\SysWOW64\WScript.exe
    "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\install.vbs"
    3⤵
    - System Location Discovery: System Language Discovery
    PID:3716
- C:\Windows\SysWOW64\schtasks.exe
  "C:\Windows\SysWOW64\schtasks.exe" /create /tn cttunesvr /tr "C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe" /sc minute /mo 1 /F
  2⤵
  - System Location Discovery: System Language Discovery
  - Scheduled Task/Job: Scheduled Task
  PID:2032

C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
1⤵
- Executes dropped EXE
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:428
- C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe
  "C:\Users\Admin\AppData\Roaming\adprovider\Dxpserver.exe"
  2⤵
  - Modifies WinLogon for persistence
  - Checks computer location settings
  - Executes dropped EXE
  - Adds Run key to start application
  - Modifies WinLogon
  - System Location Discovery: System Language Discovery
  - Modifies registry class
  - Suspicious use of WriteProcessMemory
  PID:1520
- - C:\Windows\SysWOW64\WScript.exe
    "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\install.vbs"
    3⤵
    - System Location Discovery: System Language Discovery
    PID:436

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Scheduled Task

Persistence

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Winlogon Helper DLL

Scheduled Task/Job

T1053

Scheduled Task

Privilege Escalation

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

T1547.001

Winlogon Helper DLL

Scheduled Task/Job

T1053

Scheduled Task

Defense Evasion

Modify Registry