Malware Analysis Report

2025-01-02 03:04

Sample ID 240814-sj8hjstfkk
Target Updater.exe
SHA256 4311ee23e9f4cb3432d3b0a5a78b020f89494063ba1d870298f2117970879e37
Tags
remotehost remcos discovery evasion persistence 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 Overview

score
10/10

SHA256

4311ee23e9f4cb3432d3b0a5a78b020f89494063ba1d870298f2117970879e37

Threat Level: Known bad

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

Malicious Activity Summary

remotehost remcos discovery evasion persistence rat trojan

Remcos

Remcos family

UAC bypass

Adds policy Run key to start application

Deletes itself

Adds Run key to start application

Drops file in System32 directory

Suspicious use of SetThreadContext

Enumerates physical storage devices

Unsigned PE

System Location Discovery: System Language Discovery

Suspicious behavior: MapViewOfSection

Modifies registry class

Modifies registry key

Suspicious behavior: EnumeratesProcesses

Suspicious behavior: GetForegroundWindowSpam

Suspicious use of WriteProcessMemory

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2024-08-14 15:10

Signatures

Remcos family

remcos

Unsigned PE

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

Analysis: behavioral1

Detonation Overview

Submitted

2024-08-14 15:10

Reported

2024-08-14 15:28

Platform

win10v2004-20240802-en

Max time kernel

452s

Max time network

423s

Command Line

"C:\Users\Admin\AppData\Local\Temp\Updater.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

Adds policy Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
Key created \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Deletes itself

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

Adds Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
Set value (str) \REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\Rmc-YXZARA = "\"C:\\Windows\\SysWOW64\\Remcos\\$77-Installer\"" \??\c:\program files (x86)\internet explorer\iexplore.exe N/A

Drops file in System32 directory

Description Indicator Process Target
File opened for modification C:\Windows\SysWOW64\Remcos\$77-Installer C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
File opened for modification C:\Windows\SysWOW64\Remcos C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A
File opened for modification C:\Windows\SysWOW64\Remcos \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
File opened for modification C:\Windows\SysWOW64\Remcos\$77-Installer \??\c:\program files (x86)\internet explorer\iexplore.exe N/A
File created C:\Windows\SysWOW64\Remcos\$77-Installer C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A

Suspicious use of SetThreadContext

Description Indicator Process Target
PID 3828 set thread context of 4956 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 4956 set thread context of 4852 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe

Enumerates physical storage devices

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\Updater.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:\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\reg.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Users\Admin\Downloads\NecroObfuscator\NecroObfuscator\NecroObfuscator.exe N/A
Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language C:\Windows\SysWOW64\WScript.exe N/A

Modifies registry class

Description Indicator Process Target
Key created \REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000_Classes\Local Settings \??\c:\program files (x86)\internet explorer\iexplore.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\Updater.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe N/A

Suspicious behavior: GetForegroundWindowSpam

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

Suspicious behavior: MapViewOfSection

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

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 3828 wrote to memory of 1560 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe C:\Windows\SysWOW64\cmd.exe
PID 3828 wrote to memory of 1560 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe C:\Windows\SysWOW64\cmd.exe
PID 3828 wrote to memory of 1560 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe C:\Windows\SysWOW64\cmd.exe
PID 1560 wrote to memory of 4816 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1560 wrote to memory of 4816 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 1560 wrote to memory of 4816 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 3828 wrote to memory of 4956 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3828 wrote to memory of 4956 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3828 wrote to memory of 4956 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 3828 wrote to memory of 4956 N/A C:\Users\Admin\AppData\Local\Temp\Updater.exe \??\c:\program files (x86)\internet explorer\iexplore.exe
PID 4956 wrote to memory of 2620 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 4956 wrote to memory of 2620 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 4956 wrote to memory of 2620 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\cmd.exe
PID 4956 wrote to memory of 4852 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 4956 wrote to memory of 4852 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 4956 wrote to memory of 4852 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 4956 wrote to memory of 4852 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\svchost.exe
PID 2620 wrote to memory of 5032 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 2620 wrote to memory of 5032 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 2620 wrote to memory of 5032 N/A C:\Windows\SysWOW64\cmd.exe C:\Windows\SysWOW64\reg.exe
PID 4956 wrote to memory of 1344 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\WScript.exe
PID 4956 wrote to memory of 1344 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\WScript.exe
PID 4956 wrote to memory of 1344 N/A \??\c:\program files (x86)\internet explorer\iexplore.exe C:\Windows\SysWOW64\WScript.exe

Processes

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

"C:\Users\Admin\AppData\Local\Temp\Updater.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:\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\System32\rundll32.exe

C:\Windows\System32\rundll32.exe C:\Windows\System32\shell32.dll,SHCreateLocalServerRunDll {9aa46009-3ce0-458a-a354-715610a075e6} -Embedding

C:\Users\Admin\Downloads\NecroObfuscator\NecroObfuscator\NecroObfuscator.exe

"C:\Users\Admin\Downloads\NecroObfuscator\NecroObfuscator\NecroObfuscator.exe"

C:\Windows\SysWOW64\WScript.exe

"C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\ckyswydgjudxwsgzqtryaffjqygno.vbs"

Network

Country Destination Domain Proto
US 8.8.8.8:53 mode-clusters.gl.at.ply.gg udp
US 147.185.221.21:36304 mode-clusters.gl.at.ply.gg tcp
US 8.8.8.8:53 21.221.185.147.in-addr.arpa udp
US 8.8.8.8:53 232.168.11.51.in-addr.arpa udp
US 8.8.8.8:53 81.144.22.2.in-addr.arpa udp
US 8.8.8.8:53 23.177.190.20.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 8.8.8.8:53 217.106.137.52.in-addr.arpa udp
US 8.8.8.8:53 geoplugin.net udp
NL 178.237.33.50:80 geoplugin.net tcp
NL 178.237.33.50:80 geoplugin.net tcp
US 8.8.8.8:53 50.33.237.178.in-addr.arpa udp
US 8.8.8.8:53 241.150.49.20.in-addr.arpa udp
US 147.185.221.21:36304 mode-clusters.gl.at.ply.gg tcp
US 147.185.221.21:36304 mode-clusters.gl.at.ply.gg tcp
US 147.185.221.21:36304 mode-clusters.gl.at.ply.gg tcp
US 8.8.8.8:53 103.169.127.40.in-addr.arpa udp
US 8.8.8.8:53 171.39.242.20.in-addr.arpa udp
US 8.8.8.8:53 192.142.123.92.in-addr.arpa udp
US 147.185.221.21:36304 mode-clusters.gl.at.ply.gg tcp
US 8.8.8.8:53 26.35.223.20.in-addr.arpa udp
US 8.8.8.8:53 73.144.22.2.in-addr.arpa udp
US 8.8.8.8:53 21.236.111.52.in-addr.arpa udp
US 8.8.8.8:53 tse1.mm.bing.net udp
US 150.171.28.10:443 tse1.mm.bing.net tcp
US 150.171.28.10:443 tse1.mm.bing.net tcp
US 150.171.28.10:443 tse1.mm.bing.net tcp
US 150.171.28.10:443 tse1.mm.bing.net tcp
US 150.171.28.10:443 tse1.mm.bing.net tcp
US 8.8.8.8:53 14.179.89.13.in-addr.arpa udp

Files

C:\Windows\SysWOW64\Remcos\$77-Installer

MD5 2e2946dbb102329c2b7ea3a6bc6d928e
SHA1 f71e23604985c52f609a8eaa1f907b6cf1311bbe
SHA256 4311ee23e9f4cb3432d3b0a5a78b020f89494063ba1d870298f2117970879e37
SHA512 60ab3f9a07d86dcdf37e2823d2f140f28dcd2b6120821703db1eadd2ed8ab34aea6abeb5cc6e54426374f6e780a2d9014dbd1a9d353cbb1d6ccd077e58ce57da

memory/4956-15-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-16-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-17-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-18-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4852-23-0x0000000000AA0000-0x0000000000B22000-memory.dmp

memory/4956-19-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-24-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4852-25-0x0000000000AA0000-0x0000000000B22000-memory.dmp

memory/4852-26-0x0000000000AA0000-0x0000000000B22000-memory.dmp

memory/4852-27-0x0000000000AA0000-0x0000000000B22000-memory.dmp

memory/4956-29-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-28-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-30-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-33-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-34-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-35-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-36-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-37-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-38-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-39-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-40-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-41-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-43-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-44-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-45-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-46-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-47-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-48-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-49-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-50-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-52-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-51-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-53-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-56-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-57-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-58-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/1316-59-0x00000000000F0000-0x0000000000168000-memory.dmp

memory/1316-60-0x00000000050E0000-0x0000000005684000-memory.dmp

memory/1316-61-0x0000000004AD0000-0x0000000004AFC000-memory.dmp

memory/1316-62-0x0000000004F90000-0x0000000005022000-memory.dmp

memory/1316-63-0x0000000004F60000-0x0000000004F6A000-memory.dmp

memory/4956-66-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-67-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-68-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-70-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-71-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-72-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-73-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-76-0x0000000000B00000-0x0000000000B82000-memory.dmp

memory/4956-80-0x0000000000B00000-0x0000000000B82000-memory.dmp

C:\Users\Admin\AppData\Local\Temp\ckyswydgjudxwsgzqtryaffjqygno.vbs

MD5 54a769d74f2b983cb50faaf758561dbe
SHA1 c8f0dd48ebc00ca1fefcba1b904f04d93cab3228
SHA256 bebb01f3ebac7d6849f08374aa13883c6f657df0729f1ad03a100764688e8f4c
SHA512 2ed0cebda27b59db789fe98104529b43ffcf996926d9860e87c29ef7f73be64a160e24d4595642aa824fee86726f6f05451d1268096608b9ec0352fcde2b5692