JS_NEMUCOD.ELDSAUAN

January 18, 2017
 Analysis by: Michael Jay Villanueva
 ALIASES:

JS/Nemucod.BB22!tr (Fortinet)

 PLATFORM:

Windows

 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 as an attachment to email messages spammed by other malware/grayware or malicious users. It 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:

135,956 bytes

File Type:

Other

Memory Resident:

No

Initial Samples Received Date:

18 Jan 2017

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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:

  • {Path Assigned by the User}\{Filename assigned by the User}.exe
    Note: The Default Filename is "xfs_extension.exe"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}droperez.com/fotos/photos/xfs_extension.exe

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

13.164.03

FIRST VSAPI PATTERN DATE:

18 Jan 2017

VSAPI OPR PATTERN File:

13.165.00

VSAPI OPR PATTERN Date:

19 Jan 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 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.
  • {Path Assigned by User}\xfs_extension.exe
  • {Path Assigned by User}\{Filename assigned by the User}.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_NEMUCOD.ELDSAUAN. 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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