remcos | 3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a

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\""	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.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-1-5-21-3350944739-639801879-157714471-1000\Control Panel\International\Geo\Nation	Dxpserver.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\Control Panel\International\Geo\Nation	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\Control Panel\International\Geo\Nation	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\Control Panel\International\Geo\Nation	Dxpserver.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\Control Panel\International\Geo\Nation	Dxpserver.exe

Executes dropped EXE 4 IoCs

pid	Process
1564	Dxpserver.exe
4304	Dxpserver.exe
5072	Dxpserver.exe
4980	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-1-5-21-3350944739-639801879-157714471-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\remcos = "\"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	Dxpserver.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\remcos = "\"C:\\Users\\Admin\\AppData\\Roaming\\remcos\\remcos.exe\""	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000\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\	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.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\	Dxpserver.exe

AutoIT Executable 1 IoCs

AutoIT scripts compiled to PE executables.

resource	yara_rule
behavioral2/files/0x0007000000023ca2-15.dat	autoit_exe

Suspicious use of SetThreadContext 3 IoCs

description	pid	Process	procid_target
PID 3872 set thread context of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 1564 set thread context of 4304	1564	Dxpserver.exe	105
PID 5072 set thread context of 4980	5072	Dxpserver.exe	112

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	WScript.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	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.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	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe

Modifies registry class 3 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000_Classes\Local Settings	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
Key created	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000_Classes\Local Settings	Dxpserver.exe
Key created	\REGISTRY\USER\S-1-5-21-3350944739-639801879-157714471-1000_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
4632	schtasks.exe
4328	schtasks.exe

Suspicious use of WriteProcessMemory 30 IoCs

description	pid	Process	procid_target
PID 3872 wrote to memory of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 3872 wrote to memory of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 3872 wrote to memory of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 3872 wrote to memory of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 3872 wrote to memory of 3828	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	83
PID 3828 wrote to memory of 2012	3828	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	84
PID 3828 wrote to memory of 2012	3828	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	84
PID 3828 wrote to memory of 2012	3828	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	84
PID 3872 wrote to memory of 4632	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	95
PID 3872 wrote to memory of 4632	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	95
PID 3872 wrote to memory of 4632	3872	3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe	95
PID 1564 wrote to memory of 4304	1564	Dxpserver.exe	105
PID 1564 wrote to memory of 4304	1564	Dxpserver.exe	105
PID 1564 wrote to memory of 4304	1564	Dxpserver.exe	105
PID 1564 wrote to memory of 4304	1564	Dxpserver.exe	105
PID 1564 wrote to memory of 4304	1564	Dxpserver.exe	105
PID 4304 wrote to memory of 2912	4304	Dxpserver.exe	106
PID 4304 wrote to memory of 2912	4304	Dxpserver.exe	106
PID 4304 wrote to memory of 2912	4304	Dxpserver.exe	106
PID 1564 wrote to memory of 4328	1564	Dxpserver.exe	109
PID 1564 wrote to memory of 4328	1564	Dxpserver.exe	109
PID 1564 wrote to memory of 4328	1564	Dxpserver.exe	109
PID 5072 wrote to memory of 4980	5072	Dxpserver.exe	112
PID 5072 wrote to memory of 4980	5072	Dxpserver.exe	112
PID 5072 wrote to memory of 4980	5072	Dxpserver.exe	112
PID 5072 wrote to memory of 4980	5072	Dxpserver.exe	112
PID 5072 wrote to memory of 4980	5072	Dxpserver.exe	112
PID 4980 wrote to memory of 2300	4980	Dxpserver.exe	113
PID 4980 wrote to memory of 2300	4980	Dxpserver.exe	113
PID 4980 wrote to memory of 2300	4980	Dxpserver.exe	113

C:\Users\Admin\AppData\Local\Temp\3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
"C:\Users\Admin\AppData\Local\Temp\3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe"
1⤵
- Checks computer location settings
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:3872
- C:\Users\Admin\AppData\Local\Temp\3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.exe
  "C:\Users\Admin\AppData\Local\Temp\3542d15a01ea595ee52539d6fd04e86426c2b8e0f7f43e982c05f821d1c10d6a.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:3828
- - 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:2012
- 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:4632

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:1564
- 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:4304
- - 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:2912
- 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:4328

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:5072
- 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:4980
- - 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:2300

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