arrow_back
search
close

TROJ_JORIK.ENK

June 06, 2013
 ALIASES:

TrojanDownloader:Win32/Small (Microsoft); Trojan.Win32.Jorik.Banload.cf (Kaspersky); Trojan horse Downloader.Banload.CNOE (AVG)

 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:

126,976 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

06 Jun 2013

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:

  • %System Root%\skype64x

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

Autostart Technique

This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{F5D1102F-B565-4F43-A465-70BA5030E5F2}

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\skype64x\fpsk1611DesBananaeD

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

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
explorer

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Policies\System

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Ext\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}\TypeLib

HKEY_CLASSES_ROOT\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}\InprocServer32

HKEY_CLASSES_ROOT\NewSkype64.ClsNewSkype64

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
explorer
Publish = "Version64x"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Policies\System
EnableLUA = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Ext\CLSID
{F5D1102F-B565-4F43-A465-70BA5030E5F2} = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}\TypeLib
Version = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
ProgID = "NewSkype64.ClsNewSkype64"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
TypeLib = "{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
VERSION = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
NewSkype64.ClsNewSkype64
Clsid = "{F5D1102F-B565-4F43-A465-70BA5030E5F2}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
ProxyStubClsid = "{00020424-0000-0000-C000-000000000046}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
ProxyStubClsid32 = "{00020424-0000-0000-C000-000000000046}"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\skype64x\fpsk1611.dll

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://silttac.{BLOCKED}7.f1.k8.com.br/mamore3.jpg
  • http://flavios-drinks.{BLOCKED}1.f1.k8.com.br/mirela/recept.php
  • http://omamore.{BLOCKED}m.br/mirela2/recept.php

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

Close all opened browser windows

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\Wow6432Node\Microsoft\Windows\CurrentVersion
    • explorer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Policies
    • System
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Ext
    • CLSID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {F5489FBC-5531-4CFB-95CC-07A3AB7A4240}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}
    • 1.0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0
    • FLAGS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0
    • 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0\0
    • win32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}\1.0
    • HELPDIR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
    • ProxyStubClsid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
    • ProxyStubClsid32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
    • TypeLib
  • In HKEY_CLASSES_ROOT\CLSID
    • {F5D1102F-B565-4F43-A465-70BA5030E5F2}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
    • InprocServer32
  • In HKEY_CLASSES_ROOT
    • NewSkype64.ClsNewSkype64

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_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\explorer
    • Publish = "Version64x"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Policies\System
    • EnableLUA = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Ext\CLSID
    • {F5D1102F-B565-4F43-A465-70BA5030E5F2} = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}\TypeLib
    • Version = "1.0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
    • ProgID = "NewSkype64.ClsNewSkype64"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
    • TypeLib = "{F5489FBC-5531-4CFB-95CC-07A3AB7A4240}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{F5D1102F-B565-4F43-A465-70BA5030E5F2}
    • VERSION = "1.0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\NewSkype64.ClsNewSkype64
    • Clsid = "{F5D1102F-B565-4F43-A465-70BA5030E5F2}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
    • ProxyStubClsid = "{00020424-0000-0000-C000-000000000046}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4502BF0-AEAD-4CD6-A320-84B38D29FC17}
    • ProxyStubClsid32 = "{00020424-0000-0000-C000-000000000046}"

Step 5

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 Root%\skype64x\fpsk1611.dll

Step 6

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.
  • %System Root%\skype64x

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_JORIK.ENK. 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 8

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.

  • %System Root%\skype64x\fpsk1611DesBananaeD


Did this description help? Tell us how we did.