Analysis by: Jaime Benigno Reyes

 ALIASES:

Backdoor.Win32.Androm.emby (Kaspersky)

 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: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Spammed via email

This ZEUS/ZBOT variant is found to be distributed via spam campaign in mid-2014. The spammed messages in the said campaign used a certain file storage service.

To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.

This malware is known as Dyre Banking Trojan, also called as “Dyreza."

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users. 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 attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data. It attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.

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

  TECHNICAL DETAILS

File Size: 246,784 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 11 Jun 2014
Payload: Connects to URLs/IPs

Arrival Details

This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

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

  • %Application Data%\googleupdaterr.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It drops the following component file(s):

  • %Application Data%\userdata.dat - encrypted configuration file which contains bot id and list of target banks

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It injects itself into the following processes running in the affected system's memory:

  • explorer.exe
  • chrome.exe
  • firefox.exe
  • iexplore.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • RangisMutex5

Autostart Technique

This spyware creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
GoogleUpdate = "%Application Data%\googleupdaterr.exe"

Information Theft

This spyware attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.

It attempts to steal information from the following banks and/or other financial institutions:

  • Bank of America
  • Citibank
  • NatWest
  • The Royal Bank of Scotland
  • Ulster Bank

Stolen Information

This spyware sends the gathered information via HTTP POST to the following URL:

  • {BLOCKED}.{BLOCKED}.148.6

Other Details

This spyware connects to the following URL(s) to get the affected system's IP address:

  • http://{BLOCKED}zip.com

It connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.207.151
  • {BLOCKED}.{BLOCKED}.6.61

It deletes the initially executed copy of itself

NOTES:

This spyware steals important banking information by injecting malicious codes to bank login webpages with URLs containing any of the following:

  • businessaccess.citibank.citigroup.com
  • cashproonline.bankofamerica.com
  • www.bankline.natwest.com
  • www.bankline.rbs.com
  • www.bankline.ulsterbank.ie

Some of the important banking information stolen are the following:

  • Business Code
  • Business Name
  • Company ID
  • Password
  • Token
  • User ID

The banking information is sent to the a C&C server after the user clicks on the login or submit button. The webpage then returns to the original bank login page without the malicious codes where users can log in in again normally.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.860.06
FIRST VSAPI PATTERN DATE: 13 Jun 2014
VSAPI OPR PATTERN File: 10.861.00
VSAPI OPR PATTERN Date: 14 Jun 2014

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

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • GoogleUpdate = "%Application Data%\googleupdaterr.exe"

Step 6

Remove malware/grayware files dropped/downloaded by TSPY_BANKER.WSTA. (Note: Please skip this step if the threats listed below have already been removed.)

Step 7

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.
  • %Application Data%\userdata.dat

Step 8

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.
  • %User Temp%\xwjfk.exe
  • %User Temp%\kurit.exe

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_BANKER.WSTA. 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.

Step 10

Scan your computer with your Trend Micro product to delete files detected as TSPY_BANKER.WSTA. 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.

Step 11

Search and delete the file detected as TSPY_BANKER.WSTA

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.


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