Analysis by: Cris Nowell Pantanilla

ALIASES:

VBS.Downloader.Trojan (Symantec)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware.

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

  TECHNICAL DETAILS

File Size: 9,583 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 20 Mar 2017

Arrival Details

This Trojan may be dropped by the following malware:

Download Routine

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

  • http://{BLOCKED}.{BLOCKED}.14.193/odg.jd

It saves the files it downloads using the following names:

  • %Application Data%\Roaming\{random digits}.{3 random character} ← detected as TSPY_URSNIF.AUSIMN

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.288.06
FIRST VSAPI PATTERN DATE: 20 Mar 2017
VSAPI OPR PATTERN File: 13.289.00
VSAPI OPR PATTERN Date: 21 Mar 2017

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 that dropped/downloaded VBS_NEMUCOD.ELDSATR. (Note: Please skip this step if the threats listed below have already been removed.)

Step 3

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. %Application Data%\Roaming\{random digits}.{3 random character}

Step 4

Scan your computer with your Trend Micro product to delete files detected as VBS_NEMUCOD.ELDSATR. 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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