Analysis by: Rika Joi Gregorio
ALIASES:

TrojanDownloader:Win32/Streamto.A(Microsoft), Trojan-Downloader.VBS.Small.l (v)(Sunbelt), VBS/Small.I!tr.dldr(Fortinet), Trojan-Downloader.VBS.Small.L(Ikarus), VBS/TrojanDownloader.Small.L trojan(Eset)

 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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 474 bytes
File Type: VBS
Initial Samples Received Date: 11 Feb 2014

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.

Download Routine

This Trojan saves the files it downloads using the following names:

  • c:\xmit.exe - will be deleted afterwards

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan attempts to access the following websites to download files, which are possibly malicious:

  • http://{BLOCKED}.{BLOCKED}.102.59/.others/botnet59/xmit.exe

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.600.03
FIRST VSAPI PATTERN DATE: 11 Feb 2014
VSAPI OPR PATTERN File: 10.601.00
VSAPI OPR PATTERN Date: 12 Feb 2014

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

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.  
  • c:\xmit.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as VBS_DLOADER.IHE. 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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