Analysis by: Cris Nowell Pantanilla

 ALIASES:

HEUR:Trojan-Banker.Win32.Alreay.gen (Kaspersky), Win32/TrojanDownloader.Agent.CXK trojan (NOD32)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

It steals certain information from the system and/or the user.

It connects to certain websites to send and receive information. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

129,024 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

14 Feb 2017

Payload:

Collects system information, Downloads files

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Startup%\Winslui.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Information Theft

This Trojan steals the following information:

  • Hostname
  • Username
  • OS version
  • Network settings information
  • Internet connection and settings
  • User sessions
  • User accounts
  • Network resources and domain

Stolen Information

This Trojan saves the stolen information in the following file:

  • %User Temp%\TMP{random}.tmp

(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.)

Other Details

This Trojan connects to the following website to send and receive information:

  • https://www.{BLOCKED}atch.in

It does the following:

  • It executes the following command lines to gather certain information on the affected machine:
    • hostname > %User Temp%\TMP{random}.tmp
    • whoami >> %User Temp%\TMP{random}.tmp
    • ver >> %User Temp%\TMP{random}.tmp
    • ipconfig -all >> %User Temp%\TMP{random}.tmp
    • ping www.google.com >> %User Temp%\TMP{random}.tmp
    • query user >> %User Temp%\TMP{random}.tmp
    • net user >> %User Temp%\TMP{random}.tmp
    • net view >> %User Temp%\TMP{random}.tmp
    • net view /domain >> %User Temp%\TMP{random}.tmp
    • reg query "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings" >> %User Temp%\TMP{random}.tmp
  • It is capable of downloading and executing files. As a result, malicious routines of the downloaded file(s) is exhibited on the affected machine.

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.220.04

FIRST VSAPI PATTERN DATE:

14 Feb 2017

VSAPI OPR PATTERN File:

13.221.00

VSAPI OPR PATTERN Date:

15 Feb 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

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.  %User Temp%\TMP{random}.tmp

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_RATANKBA.A. 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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