ALIASES:

PWS:Win32/Fareit.gen!C (Microsoft); PWS-Zbot-FATG!4033F58A0F47 (McAfee); Packed.Generic.406 (Symantec); Trojan-PSW.Win32.Tepfer.jpwv (Kaspersky); Trojan.Win32.Reveton.a (v) (Sunbelt); Trojan horse PSW.Generic11.MWZ (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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 164,344 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 16 May 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.

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\WinRAR

HKEY_CURRENT_USER\Software\Classes\
clsid

HKEY_CURRENT_USER\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}

HKEY_CURRENT_USER\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}\
InprocServer32

It adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR
HWID = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
Client Hash = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
6496D30F6DE8B73FBDC602D507545873 = "{random values}"

HKEY_CURRENT_USER\Software\WinRAR
17EFB9D7ED8A1FEEF13D020270C500FC = "{random values}"

HKEY_CURRENT_USER\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}\
InprocServer32
ThreadingModel = "Both"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\50515.exe
  • %User Temp%\54390.exe
  • %System Root%\RECYCLER
  • %System Root%\RECYCLER\S-1-5-21-4025279379-4087772427-2915903831-500
  • @
  • n
  • %System Root%\RECYCLER\S-1-5-18
  • $I8458E468

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This Trojan deletes itself after execution.

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 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_CURRENT_USER\Software
    • WinRAR
  • In HKEY_CURRENT_USER\Software\Classes
    • clsid
  • In HKEY_CURRENT_USER\clsid
    • {fbeb8a05-beee-4442-804e-409d6c4515e9}
  • In HKEY_CURRENT_USER\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}
    • InprocServer32

Step 3

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\WinRAR
    • HWID = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • Client Hash = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • 6496D30F6DE8B73FBDC602D507545873 = "{random values}"
  • In HKEY_CURRENT_USER\Software\WinRAR
    • 17EFB9D7ED8A1FEEF13D020270C500FC = "{random values}"
  • In HKEY_CURRENT_USER\clsid\{fbeb8a05-beee-4442-804e-409d6c4515e9}\InprocServer32
    • ThreadingModel = "Both"

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\50515.exe
  • %User Temp%\54390.exe
  • %System Root%\RECYCLER
  • %System Root%\RECYCLER\S-1-5-21-4025279379-4087772427-2915903831-500
  • @
  • n
  • %System Root%\RECYCLER\S-1-5-18
  • $I8458E468

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_KRYPTIK.QKF. 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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