Analysis by: Pearl Charlaine Espejo
ALIASES:

TrojanDownloader:BAT/Locok.A (Microsoft); Trojan-Downloader:BAT/Locky.B (F-Secure); BAT/Dldr.Locky.P.5 (Avira)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 11,549 bytes
File Type: BAT
Memory Resident: No
Initial Samples Received Date: 23 Feb 2016

Arrival Details

This Trojan may be dropped by the following malware:

  • W2KM_LOCKY.L

Installation

This Trojan drops the following component file(s):

  • %User Temp%\dasdee.vbs -detected as VBS_LOCKY.A

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://premium34.{BLOCKED}b.ru/4/4.exe

It saves the files it downloads using the following names:

  • %User Temp%\asddddd.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.382.05
FIRST VSAPI PATTERN DATE: 05 Mar 2016
VSAPI OPR PATTERN File: 12.383.00
VSAPI OPR PATTERN Date: 06 Mar 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Remove malware/grayware files that dropped/downloaded BAT_LOCKY.L. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • W2KM_LOCKY.L

Step 4

Remove malware/grayware files dropped/downloaded by BAT_LOCKY.L. (Note: Please skip this step if the threats listed below have already been removed.)

    • VBS_LOCKY.A

Step 5

Search and delete these files

[ Learn More ]
There may be some 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.
  • %User Temp%\asddddd.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as BAT_LOCKY.L. 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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