Backdoor.MSIL.ANDROM.ECVET

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Backdoor adds the following processes:

• cmd.exe /C type nul > "{malware file path and name}:Zone.Identifier"
• "{malware file path and name}"
• schtasks /delete /tn \LogOfficeDat /f
• %System%\sppsvc.exe
• "%System Root%\Program Files\Windows Media Player\wmpnetwk.exe"
• %System%\svchost.exe -k LocalServiceAndNoImpersonation
• %System%\svchost.exe -k WerSvcGroup

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It creates the following folders:

• %System Root%\LocalOffice
• %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft
• %Application Data%\LocalOffice
• %Application Data%\Sys

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Backdoor deletes the following files:

• %Windows%\Tasks\LogOfficeDat.job

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It adds the following registry entries:

HKEY_CURRENT_USER
(Default) = " -boot"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
LogOfficeDat = "%Application Data%\LocalOffice\SpoolColorLV.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
RunOnce
LogOfficeDat = "%Application Data%\LocalOffice\SpoolColorLV.exe"

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run\
LogOfficeDat

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce\
LogOfficeDat

Dropping Routine

This Backdoor drops the following files:

• %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
• %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
• {malware file path and name}:Zone.Identifier
• %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
• %Application Data%\LocalOffice\SpoolColorLV.exe

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Backdoor connects to the following possibly malicious URL:

• http://www.{BLOCKED}l.com/es/inbox.php?{random characters}

This report is generated via an automated analysis system.