ALIASES:

Worm:Win32/DuiskBot.gen (Microsoft); Generic Downloader.il (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.Mytobor.c (Kaspersky); Trojan.Win32.Packer.NTkrnl0.1 (ep) (Sunbelt); Trojan-Spy:W32/Banker.JGT (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor 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: 132,608 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 23 Dec 2012

Arrival Details

This backdoor 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 backdoor drops the following copies of itself into the affected system:

  • %System%\dllcache\winpdt.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other System Modifications

This backdoor adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\dllcache\winpdt.exe = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
DoNotAllowXPSP2 = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
DoNotAllowXPSP3 = "1"

It modifies the following registry entries:

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

(Note: The default value data of the said registry entry is 2.)

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

(Note: The default value data of the said registry entry is 2.)

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

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Ole
EnableDCOM = "N"

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
RestrictAnonymous = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
LMCompatibilityLevel = "1"

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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

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\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %System%\dllcache\winpdt.exe = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
    • DoNotAllowXPSP2 = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
    • DoNotAllowXPSP3 = "1"

Step 3

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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wuauserv
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
    • From: EnableDCOM = "N"
      To: EnableDCOM = ""Y""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
    • RestrictAnonymous = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
    • LMCompatibilityLevel = "1"

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_MYTOBOR.C. 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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