JS_DROPPER.FRM

March 20, 2017
 Analysis by: Warren Adam Sto. Tomas
 ALIASES:

JS:Trojan.Nemucod.A(BitDefender)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size:

64,215 bytes

File Type:

HTML, HTM

Memory Resident:

No

Initial Samples Received Date:

23 Feb 2017

Payload:

Drops files

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.

Installation

This Trojan drops the following files:

  • {User defined path}\{User defined name}.js - detected as JS_DLOADER.FRM
    Default name = "faktura.js"

Other Details

This Trojan does the following:

  • Once executed, it will ask the user to save the file with default name as "faktura.js"

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.264.05

FIRST VSAPI PATTERN DATE:

08 Mar 2017

VSAPI OPR PATTERN File:

13.265.00

VSAPI OPR PATTERN Date:

09 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

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

Search and delete this file

[ 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 Defined Path}\{User Defined Name}.js

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_DROPPER.FRM. 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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