BAT_BANKER.ZIP

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

BAT/Spy.Banker.AQ trojan (ESET), BAT/ProxyChanger (AVG), JS/Redir.R!tr (Fortinet)

 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:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware

This spyware may be dropped by other malware.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

15,548 bytes

File Type:

BAT

Memory Resident:

No

Initial Samples Received Date:

09 May 2013

Payload:

Steals information

Arrival Details

This spyware may be dropped by other malware.

Installation

This spyware drops the following component file(s):

  • %User Temp%\{Computer Name}.txt - also detected as BAT_BANKER.ZIP (contains proxy settings)

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

It drops the following non-malicious file:

  • %User Temp%\ok.db - infection indicator

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

Other System Modifications

This spyware modifies the following file(s):

  • %Application Data%\Mozilla\Firefox\Profiles\{random}.default\prefs.js
  • %Program Files%\Java\jre{version number}\lib\security\java.policy

(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.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "file://%User Temp%\{Computer Name}.txt"

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
Autoconfig = "1"

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
AdvancedTab = "1"

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
ResetWebSettings = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Internet Explorer\MAIN
Extensions Off Page = "http://www.google.com.br"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Extensions Off Page = "http://www.google.com.br"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "file://%User Temp%\{Computer Name}.txt"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
EnableHttp1_1 = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyHttp1.1 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Google\Chrome
AllowOutdatePlugins = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Google\Chrome
AlwaysAuthorizePlugins = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Internet Explorer\Control Panel
AdvancedTab = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Internet Explorer\Control Panel
ResetWebSettings = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Internet Explorer\Control Panel
Autoconfig = "1"

It modifies the following registry entries:

HKEY_CURRENT_USER\Microsoft\Windows\
CurrentVersion\Internet Settings
ProxyEnable = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Microsoft\Windows\
CurrentVersion\Internet Settings
ProxyHttp1.1 = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntivirusDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SystemRestore
DisableSR = "1"

(Note: The default value data of the said registry entry is 0.)

Other Details

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

  • http://{BLOCKED}.202.121/go3/{User Name}-{Computer Name}

NOTES:

It instructs browsers to retrieve pages with the following strings in their URLs through the following proxies on port 80:

  • american
  • bancodobrasil
  • banese
  • banrisul
  • bb
  • bnb
  • br
  • bradesco
  • caixa
  • cef
  • cetelem
  • citibank
  • com
  • credicard
  • hsbc
  • infoseg
  • intouch
  • itau
  • linhadefensiva
  • pagseguro
  • paypal
  • safra
  • santanderempresarial
  • santander
  • securessl
  • serasa
  • sicredi
  • tam
  • tam.com
  • voegol
  • www2.bancobrasil
  • xicaaa
  • xicaaax
  • xxxxxxx

For Proxy

  • crashoverwing.me
  • proxyrem.com
  • teamview.us

It modifies %Application Data%\Mozilla\Firefox\Profiles\{random}.default\prefs.js to change the browser's proxy settings by adding the following lines:

  • user_pref("network.{proxy}.autoconfig_url", "file://%User Temp%\{Computer Name}.txt");
  • user_pref("network.{proxy}.type", 2);

It modifies %Program Files%\Java\jre{version number}\lib\security\java.policy to grant all permissions to Java Applets by overwriting the file with the following line:

  • grant { permission java.security.AllPermission;};

It executes its component using the following command:

  • {Java Runtine Environment path}\bin\jawaw.exe -jar %User Temp%\foto.gif - detected as JAVA_BANKER.ZIP

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.906.05

FIRST VSAPI PATTERN DATE:

09 May 2013

VSAPI OPR PATTERN File:

9.907.00

VSAPI OPR PATTERN Date:

09 May 2013

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 that dropped/downloaded BAT_BANKER.ZIP

    • JAVA_BANKER.ZIP

Step 3

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\Internet Settings
    • AutoConfigURL = "file://%User Temp%\{Computer Name}.txt"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
    • Autoconfig = "1"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
    • AdvancedTab = "1"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
    • ResetWebSettings = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\MAIN
    • Extensions Off Page = "http://www.google.com.br"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • Extensions Off Page = "http://www.google.com.br"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
    • AutoConfigURL = "file://%User Temp%\{Computer Name}.txt"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
    • EnableHttp1_1 = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
    • ProxyEnable = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
    • ProxyHttp1.1 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
    • AllowOutdatePlugins = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
    • AlwaysAuthorizePlugins = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Internet Explorer\Control Panel
    • AdvancedTab = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Internet Explorer\Control Panel
    • ResetWebSettings = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Internet Explorer\Control Panel
    • Autoconfig = "1"

Step 4

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_CURRENT_USER\Microsoft\Windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = "0"
      To: ProxyEnable = 1
  • In HKEY_CURRENT_USER\Microsoft\Windows\CurrentVersion\Internet Settings
    • From: ProxyHttp1.1 = "0"
      To: ProxyHttp1.1 = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • From: AntivirusDisableNotify = "1"
      To: AntivirusDisableNotify = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • From: FirewallDisableNotify = "1"
      To: FirewallDisableNotify = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • From: UpdatesDisableNotify = "1"
      To: UpdatesDisableNotify = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore
    • From: DisableSR = "1"
      To: DisableSR = 0

Step 5

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%\ok.db
  • %User Temp%\{Computer Name}.txt

Step 6

Scan your computer with your Trend Micro product to delete files detected as BAT_BANKER.ZIP. 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 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Application Data%\Mozilla\Firefox\Profiles\{random}.default\prefs.js
  • %Program Files%\Java\jre{version number}\lib\security\java.policy


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