Analysis by: RonJay Kristoffer Caragay
ALIASES:

JS/ExtenBro.Agent.AD trojan (ESET-NOD32)

 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

This Trojan may arrive bundled with malware packages as a malware component. It 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.

This is the Trend Micro detection for files that exhibit certain behaviors.

  TECHNICAL DETAILS

File Size: Varies
File Type: JS
Memory Resident: No
Initial Samples Received Date: 15 Jan 2015

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It 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.

Download Routine

This Trojan downloads a possibly malicious file from a certain URL. The URL where this malware downloads the said file depends on the parameter passed on to it by its components.

Other Details

This is the Trend Micro detection for:

  • Browser extensions that contains malicious script

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.412.07
FIRST VSAPI PATTERN DATE: 15 Jan 2015
VSAPI OPR PATTERN File: 11.413.00
VSAPI OPR PATTERN Date: 15 Jan 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

Close all opened browser windows

Step 3

Scan your computer with your Trend Micro product to delete files detected as JS_EXTENBRO.ANK. 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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