Malware Analysis Report

2025-01-02 03:12

Sample ID 240812-gnev9asepa
Target remcos_a.exe
SHA256 de06ee1f57bc4475cf0a9a7352b0ca51b31bee6aee54429982a6ab7bdf8795e9
Tags
remotehost remcos discovery evasion rat trojan
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK

Enterprise Matrix V15

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

de06ee1f57bc4475cf0a9a7352b0ca51b31bee6aee54429982a6ab7bdf8795e9

Threat Level: Known bad

The file remcos_a.exe was found to be: Known bad.

Malicious Activity Summary

remotehost remcos discovery evasion rat trojan

Remcos family

Remcos

UAC bypass

Suspicious use of SetThreadContext

Unsigned PE

System Location Discovery: System Language Discovery

Suspicious use of SetWindowsHookEx

Suspicious use of WriteProcessMemory

Suspicious behavior: MapViewOfSection

Modifies registry key

Suspicious behavior: EnumeratesProcesses

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-08-12 05:56

Signatures

Remcos family

remcos

Unsigned PE

Description Indicator Process Target
N/A N/A N/A N/A

Analysis: behavioral1

Detonation Overview

Submitted

2024-08-12 05:56

Reported

2024-08-12 05:58

Platform

win7-20240708-en

Max time kernel

72s

Max time network

69s

Command Line

"C:\Users\Admin\AppData\Local\Temp\remcos_a.exe"

Signatures

Remcos

rat remcos

UAC bypass

evasion trojan
Description Indicator Process Target
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Windows\SysWOW64\reg.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Windows\SysWOW64\reg.exe N/A

Suspicious use of SetThreadContext

Description Indicator Process Target
PID 2692 set thread context of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 1664 set thread context of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe

System Location Discovery: System Language Discovery

discovery
Description Indicator Process Target
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\cmd.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\reg.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\cmd.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\reg.exe N/A

Modifies registry key

Description Indicator Process Target
N/A N/A C:\Windows\SysWOW64\reg.exe N/A
N/A N/A C:\Windows\SysWOW64\reg.exe N/A

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A

Suspicious behavior: MapViewOfSection

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A
N/A N/A \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Suspicious use of SetWindowsHookEx

Description Indicator Process Target
N/A N/A \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 2692 wrote to memory of 1068 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 2692 wrote to memory of 1068 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 2692 wrote to memory of 1068 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 2692 wrote to memory of 1068 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 2692 wrote to memory of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 2692 wrote to memory of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 2692 wrote to memory of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 2692 wrote to memory of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 2692 wrote to memory of 1664 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 1068 wrote to memory of 2920 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1068 wrote to memory of 2920 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1068 wrote to memory of 2920 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1068 wrote to memory of 2920 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1664 wrote to memory of 1016 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 1664 wrote to memory of 1016 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 1664 wrote to memory of 1016 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 1664 wrote to memory of 1016 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 1016 wrote to memory of 2280 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1016 wrote to memory of 2280 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1016 wrote to memory of 2280 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1016 wrote to memory of 2280 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1664 wrote to memory of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 1664 wrote to memory of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 1664 wrote to memory of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 1664 wrote to memory of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 1664 wrote to memory of 1164 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe

Processes

C:\Users\Admin\AppData\Local\Temp\remcos_a.exe

"C:\Users\Admin\AppData\Local\Temp\remcos_a.exe"

C:\Windows\SysWOW64\cmd.exe

/k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

\??\c:\program files (x86)\internet explorer\iexplore.exe

"c:\program files (x86)\internet explorer\iexplore.exe"

C:\Windows\SysWOW64\cmd.exe

/k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

C:\Windows\SysWOW64\reg.exe

C:\Windows\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

C:\Windows\SysWOW64\svchost.exe

svchost.exe

C:\Windows\SysWOW64\reg.exe

C:\Windows\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

Network

Country Destination Domain Proto
N/A 192.168.1.252:2404 tcp
N/A 192.168.1.252:2404 tcp
N/A 192.168.1.252:2404 tcp
N/A 192.168.1.252:2404 tcp

Files

memory/1664-0-0x000000007EFDE000-0x000000007EFDF000-memory.dmp

memory/1664-2-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-4-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-8-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-12-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-9-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-5-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1164-13-0x000000007EFDE000-0x000000007EFDF000-memory.dmp

memory/1164-18-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-23-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-24-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-25-0x0000000000080000-0x0000000000102000-memory.dmp

C:\ProgramData\remcos\logs.dat

MD5 816fcf1d5c3a96e059728032a2547e54
SHA1 307b21319e23f2541b59a4fde9d56b5fa2140fb9
SHA256 404bf228af5660d34eb8b9ad14f74fe35c82c3fd38bce27b22119ec4d4b11303
SHA512 318e9ee8bdbf245d5fcc8c7aaea677d66442f85b2d5a21ae2fd96b589f32c61757c85c3db24e45a04d06563c2164f4d9b02ca73a469fbebe81aa5053463efafa

memory/1664-30-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-31-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-38-0x0000000000080000-0x0000000000102000-memory.dmp

memory/1664-39-0x0000000000080000-0x0000000000102000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2024-08-12 05:56

Reported

2024-08-12 05:59

Platform

win10v2004-20240802-en

Max time kernel

148s

Max time network

150s

Command Line

"C:\Users\Admin\AppData\Local\Temp\remcos_a.exe"

Signatures

Remcos

rat remcos

UAC bypass

evasion trojan
Description Indicator Process Target
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Windows\SysWOW64\reg.exe N/A
Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" C:\Windows\SysWOW64\reg.exe N/A

Suspicious use of SetThreadContext

Description Indicator Process Target
PID 3680 set thread context of 400 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 400 set thread context of 5032 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe

System Location Discovery: System Language Discovery

discovery
Description Indicator Process Target
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\cmd.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\cmd.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\reg.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\reg.exe N/A

Modifies registry key

Description Indicator Process Target
N/A N/A C:\Windows\SysWOW64\reg.exe N/A
N/A N/A C:\Windows\SysWOW64\reg.exe N/A

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A

Suspicious behavior: MapViewOfSection

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe N/A
N/A N/A \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Suspicious use of SetWindowsHookEx

Description Indicator Process Target
N/A N/A \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 3680 wrote to memory of 2328 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 3680 wrote to memory of 2328 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 3680 wrote to memory of 2328 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe C:\Windows\SysWOW64\cmd.exe
PID 3680 wrote to memory of 400 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3680 wrote to memory of 400 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3680 wrote to memory of 400 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3680 wrote to memory of 400 N/A C:\Users\Admin\AppData\Local\Temp\remcos_a.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 400 wrote to memory of 4684 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 400 wrote to memory of 4684 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 400 wrote to memory of 4684 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 400 wrote to memory of 5032 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 400 wrote to memory of 5032 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 400 wrote to memory of 5032 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 400 wrote to memory of 5032 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 2328 wrote to memory of 4008 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 2328 wrote to memory of 4008 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 2328 wrote to memory of 4008 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 4684 wrote to memory of 4536 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 4684 wrote to memory of 4536 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 4684 wrote to memory of 4536 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe

Processes

C:\Users\Admin\AppData\Local\Temp\remcos_a.exe

"C:\Users\Admin\AppData\Local\Temp\remcos_a.exe"

C:\Windows\SysWOW64\cmd.exe

/k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

\??\c:\program files (x86)\internet explorer\iexplore.exe

"c:\program files (x86)\internet explorer\iexplore.exe"

C:\Windows\SysWOW64\cmd.exe

/k %windir%\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

C:\Windows\SysWOW64\svchost.exe

svchost.exe

C:\Windows\SysWOW64\reg.exe

C:\Windows\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

C:\Windows\SysWOW64\reg.exe

C:\Windows\System32\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f

Network

Country Destination Domain Proto
N/A 192.168.1.252:2404 tcp
US 8.8.8.8:53 8.8.8.8.in-addr.arpa udp
US 8.8.8.8:53 217.106.137.52.in-addr.arpa udp
US 8.8.8.8:53 88.210.23.2.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
N/A 192.168.1.252:2404 tcp
US 8.8.8.8:53 103.169.127.40.in-addr.arpa udp
US 8.8.8.8:53 198.187.3.20.in-addr.arpa udp
US 8.8.8.8:53 172.214.232.199.in-addr.arpa udp
N/A 192.168.1.252:2404 tcp
US 8.8.8.8:53 172.210.232.199.in-addr.arpa udp
N/A 192.168.1.252:2404 tcp
N/A 192.168.1.252:2404 tcp
US 8.8.8.8:53 tse1.mm.bing.net udp
US 150.171.27.10:443 tse1.mm.bing.net tcp
US 150.171.27.10:443 tse1.mm.bing.net tcp
US 150.171.27.10:443 tse1.mm.bing.net tcp
US 150.171.27.10:443 tse1.mm.bing.net tcp
US 150.171.27.10:443 tse1.mm.bing.net tcp
N/A 192.168.1.252:2404 tcp
N/A 192.168.1.252:2404 tcp
US 8.8.8.8:53 169.117.168.52.in-addr.arpa udp

Files

memory/400-0-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-2-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-9-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-10-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/5032-12-0x00000000010D0000-0x0000000001152000-memory.dmp

memory/5032-14-0x00000000010D0000-0x0000000001152000-memory.dmp

memory/5032-13-0x00000000010D0000-0x0000000001152000-memory.dmp

memory/5032-11-0x00000000010D0000-0x0000000001152000-memory.dmp

memory/400-6-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-3-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-1-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-19-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-20-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-21-0x0000000000E00000-0x0000000000E82000-memory.dmp

C:\ProgramData\remcos\logs.dat

MD5 77310a616b3510a28f59a91ae773df6c
SHA1 6870d45cd6eab3d31ad8c1a7080dfc40d6ad493e
SHA256 a8b586fe82550ddeab02e21f99f0dd76b5a7b373ea9b5e8fdcbafbac4e1bf8f1
SHA512 42dff0cb1f99a31fc60ed88a954b39459dc2b64874d30b9df5336d6a96830515ad456dd62fd0b97bb3e1f99cf19858d83c19f833cc9fc8ad248424e325e68d00

memory/400-26-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-27-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-32-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-34-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-39-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-40-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-45-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-46-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-52-0x0000000000E00000-0x0000000000E82000-memory.dmp

memory/400-53-0x0000000000E00000-0x0000000000E82000-memory.dmp