Technical Information
To ensure autorun and distribution
Modifies the following registry keys
- [HKCU\Software\Microsoft\Windows\CurrentVersion\Run\] 'Rmc-CA8761' = '"%ALLUSERSPROFILE%\Remcos\remcos.exe"'
- [HKLM\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\] 'Rmc-CA8761' = '"%ALLUSERSPROFILE%\Remcos\remcos.exe"'
Creates or modifies the following files
- <SYSTEM32>\tasks\updates\bsuuewuvrc
Malicious functions
To complicate detection of its presence in the operating system,
adds antivirus exclusion:
- '%WINDIR%\syswow64\windowspowershell\v1.0\powershell.exe' Add-MpPreference -ExclusionPath "%APPDATA%\bSuuEWUVrC.exe"
Injects code into
the following user processes:
- remcos.exe
Modifies file system
Creates the following files
- %APPDATA%\bsuuewuvrc.exe
- %TEMP%\tmp4a29.tmp
- %LOCALAPPDATA%\microsoft\clr_v4.0_32\usagelogs\<File name>.exe.log
- %ALLUSERSPROFILE%\remcos\remcos.exe
- %WINDIR%\softwaredistribution\sls\9482f4b4-e343-43b6-b170-9a65bc822c77\sls.cab
- %WINDIR%\softwaredistribution\sls\9482f4b4-e343-43b6-b170-9a65bc822c77\tmpd35e.tmp
- %WINDIR%\softwaredistribution\sls\855e8a7c-ecb4-4ca3-b045-1dfa50104289\sls.cab
- %WINDIR%\softwaredistribution\sls\855e8a7c-ecb4-4ca3-b045-1dfa50104289\tmpd7a4.tmp
- %WINDIR%\softwaredistribution\sls\8b24b027-1dee-babb-9a95-3517dfb9c552\sls.cab
- %WINDIR%\softwaredistribution\sls\8b24b027-1dee-babb-9a95-3517dfb9c552\tmpdbad.tmp
- %TEMP%\tmpf1d3.tmp
- %LOCALAPPDATA%\microsoft\clr_v4.0_32\usagelogs\remcos.exe.log
- %ALLUSERSPROFILE%\remcos\logs.dat
Sets the 'hidden' attribute to the following files
- %APPDATA%\bsuuewuvrc.exe
Network activity
UDP
- DNS ASK settings-win.data.microsoft.com
- DNS ASK ir####v1.ddns.net
Miscellaneous
Creates and executes the following
- '%ALLUSERSPROFILE%\remcos\remcos.exe'
Restarts the analyzed sample
Executes the following
- '%WINDIR%\syswow64\schtasks.exe' /Create /TN "Updates\bSuuEWUVrC" /XML "%TEMP%\tmp4A29.tmp"
- '%WINDIR%\syswow64\schtasks.exe' /Create /TN "Updates\bSuuEWUVrC" /XML "%TEMP%\tmpF1D3.tmp"
- '%WINDIR%\syswow64\windowspowershell\v1.0\powershell.exe' Add-MpPreference -ExclusionPath "%APPDATA%\bSuuEWUVrC.exe"' (with hidden window)
- '%WINDIR%\syswow64\schtasks.exe' /Create /TN "Updates\bSuuEWUVrC" /XML "%TEMP%\tmp4A29.tmp"' (with hidden window)
- '%WINDIR%\syswow64\schtasks.exe' /Create /TN "Updates\bSuuEWUVrC" /XML "%TEMP%\tmpF1D3.tmp"' (with hidden window)
