JS_DLOADER.YYF

January 11, 2016
 Analysis by: Sammy Chua
 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 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:

HTML, HTM, JS

Memory Resident:

No

Initial Samples Received Date:

11 Jan 2016

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.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://b.{BLOCKED}g.jp/iframe?c=2wzBV9u
  • http://s.{BLOCKED}ghttag.com/iframe
  • {host}/javascript/fp_base_bd_ga_6.0.60.js
  • http://ai.{BLOCKED}g.jp/bdv/yahoo/javascript/brandpanel_triple/1.0.1/brandpanel_triple.js
  • http://yads.c.{BLOCKED}g.jp/js/yads.js
  • http://k.{BLOCKED}g.jp/images/ds/ult/toppage/rapidjp-1.0.0.js
  • http://yads.c.{BLOCKED}g.jp/js/yads-async.js
  • http://k.{BLOCKED}g.jp/images/listing/tool/yads/yads-timeline-ex.js

  SOLUTION

Minimum Scan Engine:

9.800

VSAPI OPR PATTERN File:

5.883.00

VSAPI OPR PATTERN Date:

08 Apr 2009

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

Close all opened browser windows

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_DLOADER.YYF. 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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