TROJ_ZBOT.BTR

 Modified by: Marfel Tiamzon

 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan 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. Once users access any of the monitored sites, it starts logging keystrokes. It attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.

It attempts to get information from a list of banks or financial institutions.

It checks for the presence of the following processes which are related to Outpost Personal Firewall and ZoneLabs Firewall Client:

  • outpost.exe
  • zlclient.exe

It terminates if either of the said processes exist. This is to ensure that it runs uninterrupted. It also has rootkit capabilities, which enables it to hide its processes and files from the user.

  TECHNICAL DETAILS

File Size:

136,704 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Aug 2010

Payload:

Steals information, Downloads files, Drops files, Terminates processes

Infection Points

This Trojan arrives as a file downloaded from the following URLs:

  • http://{BLOCKED}ers.com/it507/it507.exe

Installation

This Trojan drops copies of itself in the Windows system folder and appends garbage code to the dropped copy to avoid easy detection. The dropped copies uses the following file names:

  • sdra64.exe

It then creates the following non-malicious file(s):

  • %System%\lowsec\local.ds - copy of the encrypted downloaded file
  • %System%\lowsec\user.ds - used to save the gathered information

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It creates the following folders with attributes set to System and Hidden to prevent users from discovering and removing its components:

  • %System%\lowsec

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

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

  • _AVIRA_2109

It injects itself into the following processes as part of its memory residency routine:

  • SVCHOST.EXE
  • WINLOGON.EXE

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = %System%\userinit.exe, %System%\sdra64.exe,

(Note: The default value data of the said registry entry is %System%\userinit.exe,.)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Network
UID = {Computer name}_{Random numbers}

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 0

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}ers.com/it507/it507.txt

Information Theft

This Trojan 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.

Once users access any of the monitored sites, it starts logging keystrokes.

It attempts to access a website to download a file which contains information where the Trojan can download an updated copy of itself, and where to send its stolen data. This configuration file also contains the following list of targeted bank-related websites from which it steals information:

  • *.businesswaybnl.it/newcorporate/webcontoc/login/login*
  • *.facebook.com/*
  • *.mcafee.com/*
  • *.microsoft.com/*
  • *ib.cim-italia.it/eb/*
  • http*://*homebanking.bpergroup.net*
  • https://banking.*.de/cgi/ueberweisung.cgi/*
  • https://ib.cim-italia.it/*
  • https://internetbanking.gad.de/banking/*
  • https://paschiinazienda.mps.it*pass_operat;pass_dispotO
  • https://qweb.quercia.com/unicredito/unicreditbanca/Main.aspx
  • https://web.secservizi.it/HomeBanking/Bonifico*
  • https://www.citibank.de/*/jba/mp#/SubmitRecap.do
  • https://www.csebanking.it/ibportal/home-LISTA_MOVIMENTI.do*
  • https://www.sella.it/AuthenticationDelegatedServlet

The downloaded file contains information where the malware can download an updated copy of itself, and where to send its stolen data.

Note that the contents of the file, hence the list of websites to monitor, may change any time.

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

  • Banca On Line - Sella.it
  • Citibank
  • Facebook
  • GAD
  • McAfee
  • Microsoft
  • SEB
  • Secservizi

Attacked Entities

This Trojan attempts to get information from a list of banks or financial institutions.

Stolen Information

This Trojan saves the stolen information in the following file:

  • %System%\lowsec\user.ds

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}ers.com/it507/it507gat.php

Other Details

This Trojan checks for the presence of the following processes which are related to Outpost Personal Firewall and ZoneLabs Firewall Client:

  • outpost.exe
  • zlclient.exe

It terminates if either of the said processes exist. This is to ensure that it runs uninterrupted. It also has rootkit capabilities, which enables it to hide its processes and files from the user.

It did not exhibit backdoor routines during testing.

Variant Information

This Trojan has the following MD5 hashes:

  • acfd4f8d4733d4fd67d270e0155df6f6

It has the following SHA1 hashes:

  • 796760c9bc3fb1d807156f02345df1d8d619b474

  SOLUTION

Minimum Scan Engine:

8.900

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and delete files detected as TROJ_ZBOT.BTR using the Recovery Console

[ Learn More ]

Step 3

Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit =%System%\userinit.exe, %System%\sdra64.exe,
      To: %System%\userinit.exe,

Step 4

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Network
    • UID ={Computer name}_{Random numbers}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\SharedAccess\Parameters\ FirewallPolicy\StandardProfile
    • EnableFirewall =0

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_ZBOT.BTR. 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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