TROJ_LUKICSEL.F

January 29, 2013
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

Trojan:Win32/Lukicsel.F (Microsoft), Troj/Oficla-Gen (Sophos), W32/Oficla.ABIE!tr (Fortinet), W32/Trojan2.MWKE (F-Prot), Win32/Lukicsel.O trojan (ESET), Trojan.Win32.Delf.xtd (VBA32)

 PLATFORM:

Windows 2000, Windows XP (32-bit and 64-bit), Windows Server 2003, Windows Vista (32-bit and 64-bit), Windows 7 (32-bit and 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

45,056 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

25 Jan 2013

Payload:

Drops files

Arrival Details

This Trojan may be dropped by other malware.

Installation

This Trojan drops the following files:

  • %System%\crt.dat

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
DllName = "cryptnet32.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
Startup = "WinLogonStartupEvent"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
Logoff = "WinlogonLogoffEvent"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
Shutdown = "WinlogonLogoffEvent"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
Asynchronous = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32
Impersonate = "0"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon\
Notify\cryptnet32

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.680.04

FIRST VSAPI PATTERN DATE:

25 Jan 2013

VSAPI OPR PATTERN File:

9.681.00

VSAPI OPR PATTERN Date:

26 Jan 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

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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify
    • cryptnet32

Step 4

Search and delete this file

[ 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.
  • %System%\crt.dat

Step 5

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


Did this description help? Tell us how we did.