Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 the files it drops, prompting the affected system to exhibit the malicious routines they contain.

  TECHNICAL DETAILS

File Size: 1,206,744 bytes
File Type: EXE
Initial Samples Received Date: 23 Jan 2013

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:

  • %AppDataLocal%\Microsoft\winsrv64\unins000.dat
  • %AppDataLocal%\Microsoft\winsrv64\unins000.exe
  • %AppDataLocal%\Microsoft\winsrv64\wincl.exe
  • %AppDataLocal%\Microsoft\winsrv64\winsrv64.dat
  • %AppDataLocal%\Microsoft\winsrv64\winsrv64.dll
  • %AppDataLocal%\Microsoft\winsrv64\winsrv64.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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)

It creates the following folders:

  • %AppDataLocal%\Microsoft\winsrv64

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)

Dropping Routine

This backdoor executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.