BKDR_KULUOZ.XTRO

May 23, 2014
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

Backdoor.Win32.Androm.dttd(Kaspersky), TrojanDownloader:Win32/Kuluoz.D(Microsoft),

 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:
 INFORMATION EXPOSURE:

  • 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.

  TECHNICAL DETAILS

File Size:

99,840 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

23 May 2014

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.

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random characters} = %AppDataLocal%\{random filename}.exe "

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\{random characters}
{random characters} = "{hex values}"

Dropping Routine

This backdoor drops the following files:

  • %AppDataLocal%\{random filename}.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.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.29.205
  • http://{BLOCKED}.{BLOCKED}.246.188
  • http://{BLOCKED}.{BLOCKED}.1.189
  • http://{BLOCKED}.{BLOCKED}.59.5
  • http://{BLOCKED};{BLOCKED}.157.126
  • http://{BLOCKED}.{BLOCKED}.114.64