BKDR_KULUOZ.FAA

March 05, 2014
 Modified by: Ardin Christopher Maglalang
 ALIASES:

Troj/Agent-AFHS(Sophos), TrojanDownloader:Win32/Kuluoz.D(Micrososft), Trojan.Win32.Generic.pak!cobra(Sunbelt)

 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 as an attachment to email messages spammed by other malware/grayware or malicious users. It 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:

121,344 bytes

File Type:

EXE

Arrival Details

This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 a copy of itself in the following folders using different file names:

  • %Application Data%\{Random Filename}.exe

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

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} = "%Application Data%\{Random Filename}.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\{Random Key}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\{Random Key}
{Random} = "{Hex Values}"

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.88.42:8080/{Generated Value}
  • http://{BLOCKED}.{BLOCKED}7.4.27:8080/{Generated Value}
  • http://{BLOCKED}.{BLOCKED}.116.171:8080/{Generated Value}
  • http://{BLOCKED}0.{BLOCKED}4.253.222:443/{Generated Value}
  • http://{BLOCKED}3.{BLOCKED}.200.33:8080/{Generated Value}
  • http://{BLOCKED}2.{BLOCKED}.64.35:8080/{Generated Value}