TROJ_NEOP.A


 ALIASES:

Trojan:Win32/VB, Trojan:Win32/VB (Microsoft); Generic PWS.y!1dd (McAfee); PAK:UPX, ARC:BatToExe, [data0.zst]:Trojan-PSW.Win32.Chisburg.a, [data0.zst]:Trojan-PSW.Win32.Chisbur (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Dropped:Trojan.Generic.1611217 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan 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:

346,112 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

09 Jul 2012

Arrival Details

This Trojan 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 Trojan creates the following folders:

  • %User Temp%\1.tmp

(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.)

Autostart Technique

This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAcce ss

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuause rv

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\1.tmp

(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.)

It 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"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAcce ss
Start = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wscsvc
Start = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wuause rv
Start = "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 {C0FE0177-5693-4537-9331-A7402AD82D40}.)

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 Trojan drops the following files:

  • data1.zst
  • data0.zst
  • %Windows%\BRIAN-7E01BAA8.txt

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Restart in Safe Mode

[ Learn More ]

Step 3

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\SYSTEM\CurrentControlSet\Services
    • SharedAcce ss
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • wscsvc
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • wuause rv

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_CURRENT_USER\Software\Microsoft\Internet Account Manager\Accounts
    • AssociatedID = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager
    • Server ID = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAcce ss
    • Start = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
    • Start = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wuause rv
    • Start = "4"

Step 5

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\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 = ""{C0FE0177-5693-4537-9331-A7402AD82D40}""
  • 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 6

Search and delete these files

[ Learn More ]
There may be some component 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.
  • data1.zst
  • data0.zst
  • %Windows%\BRIAN-7E01BAA8.txt

Step 7

Search and delete this folder

[ 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 Temp%\1.tmp

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_NEOP.A. 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 9

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.

  • %User Temp%\1.tmp


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