TSPY_AMBLER.KB

October 09, 2012
 Analysis by: Karl Dominguez
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

It creates certain registry entries that affect the Internet Settings of the affected system.

It steals confidential information from the affected system, such as user credentials, passwords, and online banking details.

This spyware may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

36,352 bytes

File Type:

DLL

Initial Samples Received Date:

19 Dec 2010

Payload:

Drops files, Modifies system registry

Arrival Details

This spyware may be dropped by the following malware:

  • TROJ_AMBLER.KB

Installation

This spyware drops the following files:

  • %User Profile%\Application Data\Sun\cetw.txt
  • %User Profile%\Application Data\Sun\lfmt.txt
  • %User Profile%\Application Data\Sun\{malware file name}_shrd
  • %User Profile%\Application Data\Sun\rwbbr.txt
  • %User Profile%\Application Data\Sun\oietr.txt
  • %User Profile%\Application Data\Sun\cngrh.txt
  • %User Profile%\Application Data\Sun\vntw.txt
  • %User Profile%\Application Data\Sun\mogr.txt
  • %User Profile%\Application Data\Sun\cetw.txt
  • %User Profile%\Application Data\Sun\mxd1.txt
  • %User Profile%\Application Data\Sun\vwvn.txt
  • %User Profile%\Application Data\Sun\crff.txt
  • %User Profile%\Application Data\Sun\xkelf.txt
  • %User Profile%\Application Data\Sun\opfwe.txt
  • %User Profile%\Application Data\Sun\lofwfg.txt
  • %User Profile%\Application Data\Sun\ffefx.txt

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %User Profile%\Application Data\Sun

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It injects codes into the following process(es):

  • Iexplore.exe
  • firefox.exe

Autostart Technique

This spyware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
StubPath = rundll32.exe %User Profile%\Application Data\Sun\{malware file name}.dll", UnregisterDll

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Clock

HKEY_CURRENT_USER\Software\Microsoft\
Clock\0

HKEY_CURRENT_USER\Software\Microsoft\
Clock\7

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
Enabled = 0

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
EnabledV8 = 0

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
ShownVerifyBalloon = 3

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
TabProcGrowth = 0

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Security
DisableFixSecuritySettings = 1

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Security
DisableSecuritySettingsCheck = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
(default) = Transaction Manager

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
Locale = EN

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
StubPath = rundll32.exe %User Profile%\Application Data\Sun\{malware file name}.dll", UnregisterDll

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
IsInstalled = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{24EA4F28-B636-43C1-BCE6-F287B56E42D2}
Version = 4,3,6,3

HKEY_CURRENT_USER\Software\Microsoft\
Clock\0
knhbc = 23052011_144849_3899578

Stolen Information

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

  • http://{BLOCKED}ana.info/newfolder/myu.php
  • http://{BLOCKED}ana.info/newfolder/myc.php
  • http://{BLOCKED}ana.info/newfolder/myi.php
  • http://{BLOCKED}ana.info/newfolder/myn.php
  • http://{BLOCKED}ana.info/newfolder/myl.php

NOTES:
It may create/modify the following registry entries:

  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\1
    1400 = 0
    1200 = 0
    1405 = 0
    2500 = 3
    1809 = 3

  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    1400 = 0
    1200 = 0
    1405 = 0
    2500 = 3
    1809 = 3

  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    1400 = 0
    1200 = 0
    1405 = 0
    2500 = 3
    1809 = 3

  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    1400 = 0
    1200 = 0
    1405 = 0
    2500 = 3
    1809 = 3

(Note: The default values are user-defined.)

It steals the following information:
  • Passwords stored in pstorec.dll
  • Microsoft Outlook Express user credentials
  • Internet Explorer Password-protected sites
  • MSN Explorer login credentials
  • Internet Explorer auto-complete fields
  • Internet Explorer auto-complete passwords
  • Bank of America user credentials
  • Internet cookies
  • Certificates
It also has the following capabilities:
  • Keylog
  • Delete itself
  • Delete cookies
  • Shutdown system
  • Enumerate drives

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

7.886.07

FIRST VSAPI PATTERN DATE:

08 Mar 2011

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

Remove malware files dropped/downloaded by TSPY_AMBLER.KB

    TROJ_AMBLER.KB

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ 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\Active Setup\Installed Components
    • {24EA4F28-B636-43C1-BCE6-F287B56E42D2}
  • In HKEY_CURRENT_USER\Software\Microsoft
    • Clock

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\Internet Explorer\PhishingFilter
    • Enabled = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
    • EnabledV8 = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
    • ShownVerifyBalloon = 3
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • TabProcGrowth = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • NoProtectedModeBanner = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Security
    • DisableFixSecuritySettings = 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Security
    • DisableSecuritySettingsCheck = 1

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result. %User Profile%\Application Data\Sun

Step 7

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