Modified by: Jaime Benigno Reyes

ALIASES:

VirTool:Win32/DelfInject.gen!X (Microsoft); BackDoor-DOQ.gen.w (McAfee); Downloader (Symantec); Trojan.Win32.Buzus.ckzu (Kaspersky); Trojan.Win32.Buzus.ckzu (v) (Sunbelt); Trojan.Generic.4666328 (F-Secure)

 PLATFORM:

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

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  TECHNICAL DETAILS

File Size: Varies
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 28 Jun 2014

Arrival Details

This malware arrives via the following means:

  • Infected by PE_BUZUS.A-O

Installation

This file infector drops and executes the following files:

  • %System%\{random filename}.exe - detected as PE_BUZUS.A-O

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

It drops the following non-malicious files:

  • %System%\c_l{random 4-digit number}.nls
  • %System%\_Setup.bat (deleted afterwards)

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

File Infection

This is the Trend Micro detection for files infected by:

  • PE_BUZUS.A-O

NOTES:

It lists all the file names (base names) of all .DLL files inside the %System% folder that don't have an equivalent .EXE, .NLS or .CPL files. From this list, it will randomly select the file name it will use for the dropped file in the %System% folder detected as PE_BUZUS.A-O.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.700
VSAPI OPR PATTERN File: 10.889.00
VSAPI OPR PATTERN Date: 28 Jun 2014

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

Remove malware/grayware files that dropped/downloaded PE_BUZUS.A. (Note: Please skip this step if the threats listed below have already been removed.)

Step 3

Identify and terminate files detected as PE_BUZUS.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. 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.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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%\c_l{random 4-digit number}.nls

Step 5

Scan your computer with your Trend Micro product to clean files detected as PE_BUZUS.A. 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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