ALIASES:

Trojan:Win32/Sisron (Microsoft); [00009e60.EXE\00009e60.EXE\00005d64.EXE]:PWS-Banker!gyp (McAfee); Infostealer.Bancos (Symantec); PAK:UPX, Trojan-Banker.Win32.Bancos.ra, Trojan-Banker.Win32.Bancos.ra (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Gen:Trojan.Heur.bmKfrrodNXciy (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

  TECHNICAL DETAILS

File Size: 30,208 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Nov 2011

Arrival Details

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

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
avst = "{malware path and file name}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
krnl = "%System%\krnlx86.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
avst = "%System%\lssas.exe"

Other System Modifications

This spyware adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts
AssociatedID = {random values}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager
Server ID = 4

It modifies the following registry entries:

HKEY_CURRENT_USER\Identities
Last Username = "Main Identity"

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

HKEY_CURRENT_USER\Identities
Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"

(Note: The default value data of the said registry entry is {5D1D9894-914A-4AF9-BD82-81F349A83013}.)

HKEY_CURRENT_USER\Identities
Identity Login = 9853

(Note: The default value data of the said registry entry is 98053.)

HKEY_CURRENT_USER\Identities
Identity Ordinal = 2

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

Dropping Routine

This spyware drops the following files:

  • %Program Files%\Internet Explorer\xpshimslg.dll
  • %System Root%\pcname.reg

(Note: %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).. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

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

Restart in Safe Mode

[ Learn More ]

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\Run
    • avst="{malware path and file name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • krnl="%System%\krnlx86.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • avst="%System%\lssas.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager\Accounts
    • AssociatedID={random values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager
    • Server ID=4

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Identities
    • From: Last Username="Main Identity"
      To: Last Username=Main Identity
  • In HKEY_CURRENT_USER\Identities
    • From: Last User ID="{341F68BA-C841-4200-A7B4-3D5CFF202166}"
      To: Last User ID={5D1D9894-914A-4AF9-BD82-81F349A83013}
  • In HKEY_CURRENT_USER\Identities
    • From: Identity Login=9853
      To: Identity Login=98053
  • In HKEY_CURRENT_USER\Identities
    • From: Identity Ordinal=2
      To: Identity Ordinal=1

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %Program Files%\Internet Explorer\xpshimslg.dll
  • %System Root%\pcname.reg

Step 6

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