BKDR_DASERF.NZV

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 executes then deletes itself afterward.

It does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive 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 and executes the following files:

• %User Temp%\{temp filename}.bat -> used to delete the malware and itself

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

It executes then deletes itself afterward.

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

• Global\24203

Autostart Technique

This Backdoor starts the following services:

• ServiceName = "swprv3"
  DisplayName = "Microsoft Software Shadow Copy Provider System Information"
  BinaryPathName = """C:\Program Files\internet explorer\pd7.exe"""

Other System Modifications

This Backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
Type = 272

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
Start = 2

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
ErrorControl = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
ImagePath = "%Program Files%\internet explorer\pd7.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
DisplayName = "Microsoft Software Shadow Copy Provider System Information"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\swprv3
Description = "???Manages software-based volume shadow copies taken by the Volume Shadow Copy service. If this service is stopped, software-based volume shadow copies cannot be managed. If this service is disabled, any services that explicitly depend on it will fail to start."

Propagation

This Backdoor does not have any propagation routine.

Backdoor Routine

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

• Execute Powershell commands
• Uninstall itself
• Install PlugIn
• Change Activity Time
• Change download URL
• Sleep
• Gather System Information
• Perform Remote Shell
• Create or terminate processes
• Upload, Download, or Execute Files
• Enumerate all drives with corresponding drive types
• Get sha1/md5 of file
• Search, Move, or Delete files
• Get File Information
• Create, Change, or Delete Directory
• Enumerate files and directories

It connects to the following websites to send and receive information:

• http://{BLOCKED}.{BLOCKED}.204.100/0002/phptunnel.php?t0=00000956&t1=0&t2=c45d5aca&t3=0&t6=1000

Dropping Routine

This Backdoor drops the following files:

• %Program Files%\internet explorer\pd7.exe

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Information Theft

This Backdoor gathers the following data:

• Computer Name
• System Default Language ID
• OS Version
• Is administrator
• Is 64-bit
• Available Disk Space
• User Name