Analysis by: Jennifer Gumban
ALIASES:

Trojan.Win32.Generic!BT (Sunbelt); TR/Zusy.71386.1 (Antivir)

 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: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size: 115,200 bytes
File Type: DLL
Initial Samples Received Date: 24 Nov 2013

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This Trojan deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = "http=127.0.0.1:8888;https=127.0.0.1:8888;"

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Download Routine

This Trojan accesses the following websites to download files:

  • http://www.{BLOCKED}ouk.com/ini.txt
  • http://www.{BLOCKED}ouk.com/1.jpg

It saves the files it downloads using the following names:

  • %Temporary Internet Files%\Content.IE5\{random folder name}\1[1].jpg
  • %Temporary Internet Files%\Content.IE5\{random folder name}\ini[1].jpg

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

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • www.yahoo.com

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.430.01
FIRST VSAPI PATTERN DATE: 20 Nov 2013
VSAPI OPR PATTERN File: 10.431.00
VSAPI OPR PATTERN Date: 21 Nov 2013

Step 1

Scan your computer with your Trend Micro product to delete files detected as TROJ_AIBATOOK.AH. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 2

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.


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