Analysis by: Adrianne Chester Camat
 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: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan creates folders where it drops its files.

It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 251,128 bytes
File Type: , EXE
Memory Resident: No
Initial Samples Received Date: 16 Apr 2013

Installation

This Trojan drops the following files:

  • %Application Data%\AdobeFlash\{random characters}.crx - Detected as TROJ_EXTADB.US
  • %Application Data%\AdobeFlash\update.xml

(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 Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Google\Chrome\ExtensionInstallForcelist
1 = "{random characters};%Application Data%\AdobeFlash\update.xml"

Backdoor Routine

This Trojan connects to the following websites to send and receive information:

  • http://{BLOCKED}ked.net/king.txt
  • http://{BLOCKED}ked.net/{random characters}.crx - detected as TROJ_EXTADB.US

NOTES:

The downloaded .CRX file is a Google Chrome extension which performs other malicious routines.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.860.06
FIRST VSAPI PATTERN DATE: 16 Apr 2013
VSAPI OPR PATTERN File: 9.861.00
VSAPI OPR PATTERN Date: 17 Apr 2013

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove malware/grayware files dropped/downloaded by TROJ_FAKEADB.US

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\ExtensionInstallForcelist
    • 1 = "{random characters};%Application Data%\AdobeFlash\update.xml"

Step 4

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
  • %Application Data%\AdobeFlash\{random characters}.crx
  • %Application Data%\AdobeFlash\update.xml

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEADB.US. 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.


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