Analysis by: Sammy Chua
ALIASES:

TrojanDownloader:JS/Inexsmar.D (Microsoft); Trojan.Malscript (Symantec); Worm.JS.Feebs (Ikarus);

 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

Infection Channel: Downloaded from the Internet, Dropped by other malware

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 may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size: Varies
File Type: JS, HTML, HTM
Memory Resident: No
Initial Samples Received Date: 15 Jul 2015
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.

It may be hosted on a website and run when a user accesses the said website.

Installation

This Trojan drops and executes the following files:

  • %User Temp%\Internet Explorer Smart Recovery.exe - detected as TROJ_DLOADR.YMJ

(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.)

NOTES:

It reports to the following URL if the dropped file is successfully executed:

  • http://{BLOCKED}o.applibrary.org/readme.php?type=execution&result=created_and_executed

It reports to the following URL if the dropped file is not executed:

  • http://{BLOCKED}o.applibrary.org/readme.php?type=execution&result=created_but_not_executed&err_num={error number}&err_desc={error description}

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.792.05
FIRST VSAPI PATTERN DATE: 15 Jul 2015
VSAPI OPR PATTERN File: 11.793.00
VSAPI OPR PATTERN Date: 16 Jul 2015

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 dropped/downloaded by JS_FEEBS.GEO. (Note: Please skip this step if the threats listed below have already been removed.)

    • TROJ_DLOADR.YMJ

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_FEEBS.GEO. 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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