TROJ_KATUSHA.SS

October 09, 2012
 Analysis by: Sabrina Lei Sioting
 ALIASES:

Rogue:Win32/FakeRean (Microsoft), Packed.Win32.Katusha.o (Kaspersky), TR/PCK.Katusha.O.3486 (Antivir), W32/Katusha.O!tr (Fortinet), Trojan-Downloader.Win32.Ufraie (Ikarus),

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

193,024 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Sep 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • RUNACAD97A065C20A69A8CEE16E90F44B068

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{malware name} = "{malware path}\{malware name}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
{malware name} = "{malware path}\{malware name}.exe"

Other System Modifications

This Trojan adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
MediaPlayer\Setup\Files

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • http://www.yahoo.com
  • http://www.microsoft.com
  • http://google.com

It connects to the following possibly malicious URL:

  • http://{BLOCKED}nalpack.us/httpss/v={random numbers}&step={random numbers}&hostid={random numbers}

It requires the following additional components to properly run:

  • c:\asd

However, as of this writing, the said sites are inaccessible.

NOTES:

This Trojan drops six copies of itself, one copy each in the random folders found in the Program Files folder. The file name used is based on a file found inside the folder where a copy is to be dropped.

  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

Identify and terminate files detected as TROJ_KATUSHA.SS

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer\Setup
    • Files

Step 4

Delete the registry entry with an unknown data 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\Microsoft\Windows\CurrentVersion\Run
    • {malware name} = "{malware path}\{malware name}.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
    • {malware name} = "{malware path}\{malware name}.exe"

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_KATUSHA.SS. 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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