Analysis by: Sabrina Lei Sioting
ALIASES:

Win32/Qbot.BD (Eset), JS/Agent.GUD!tr.dldr (Fortinet), Trojan-Downloader.JS.Agent (Ikarus), Trojan-Downloader.JS.Agent.gud (Kaspersky), JS/Downloader-FCQ (McAfee), TrojanDownloader:JS/Qakbot.K (Microsoft), Troj/VBS-BF (Sophos),

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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 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 dropped by other malware.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 6,382 bytes
File Type: JS
Initial Samples Received Date: 17 Sep 2013

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 dropped by the following malware:

  • BKDR_QAKBOT
  • WORM_QAKBOT

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}tkrich.net/4
  • http://{BLOCKED}iakfuuasd.net/4
  • http://{BLOCKED}carusled.org/4
  • http://{BLOCKED}asudskfoe.org/4
  • http://{BLOCKED}uytdk.info/4
  • http://{BLOCKED}kiev.ua/4
  • http://{BLOCKED}vtkn.in.ua/4
  • http://{BLOCKED}mausj.org/4
  • http://{BLOCKED}eavmauytdk.info/4
  • http://{BLOCKED}nz.net/4
  • http://{BLOCKED}n.org/4
  • http://{BLOCKED}iev.ua/4
  • http://{BLOCKED}istr.in/4

It saves the files it downloads using the following names:

  • %Temp%\{script name}.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine: 9.300

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

Remove the malware/grayware file dropped/downloaded by JS_QAKBOT.GR

    BKDR_QAKBOT
    WORM_QAKBOT

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. %Temp%\{script name}.tmp

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_QAKBOT.GR. 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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