Backdoor.Win64.KIVARS.AA

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.

It does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system.

It steals certain information from the system and/or the user. It logs a user's keystrokes to steal information.

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 drops the following files:

• %User Temp%\win9809.tmp -> encrypted file containing keylogged keystrokes

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

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• AAA%332^*7

Propagation

This Backdoor does not have any propagation routine.

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

• Get Idle Time
• Send Keylogged File Contents
• Delete Keylogged File
• Get Drives' Type
• Find File/s Or Folder/s names and timestamp
• Download Component File
• Start Process
• Delete File
• Create Directory
• Execute Command
• Delete Directory
• Show Window
• Destroy Window
• Set Window to Foreground
• Hide Window
• Set Window Text
• Get Screen Resolution
• Take a screenshot
• Send Mouse Input
• Send keyboard Input
• Terminate Process
• Enumerate Processes
• Read Data from Pipe Connection
• Write to File
• Get PC Name, OS Version, and User Name

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• http://{BLOCKED}.{BLOCKED}.92.110:443

Rootkit Capabilities

This Backdoor does not have rootkit capabilities.

Download Routine

This Backdoor saves the files it downloads using the following names:

• %User Temp%\werfc0908.dat -> encrypted component file loaded by the malware

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

Information Theft

This Backdoor steals the following information:

• Computer Name
• User Name
• IPv4 Address
• Current Process ID
• Volume Information
• Locale Info
• Keyboard Layout Name
• The following environment paths of the machine:
  • %Application Data%\Microsoft\Windows\Recent
  • %Desktop%
  • %User Profile%\Documents

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

It logs a user's keystrokes to steal information.

Other Details

This Backdoor does not exploit any vulnerability.