BUPTBOOT

October 06, 2015
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

Virus:DOS/Bupt.BOOT (Microsoft); Boot.Bupt9146 (VBA32); Bupt (Sophos); Virus.Boot.Bupt (v) (Sunbelt); Virus.Boot.Bupt9146 (Ikarus); Bubj (McAfee); WelcomB.A (exact) (F-Prot); Virus.Boot.Bupt9146 (Kaspersky); WelcomB.A (Boot image) (BitDefender)

 PLATFORM:

Windows, DOS

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

  • Threat Type: Others

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Copies itself in floppy drives

This malware may arrive using one or multiple arrival methods.

The said files contain data it writes into the MBR (Master Boot Record). It does the said action to enable it to start even before the operating system is loaded.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size:

1,474,560 bytes

File Type:

DOS

Memory Resident:

Yes

Initial Samples Received Date:

18 Sep 2015

Arrival Details

This malware arrives via the following means:

  • floppy disk drive

Autostart Technique

This malware e said files contain data it writes into the MBR (Master Boot Record). It does the said action to enable it to start even before the operating system is loaded.

Backdoor Routine

This malware does not have any backdoor routine.

NOTES:

This virus infects boot sectors of floppy disks and partition tables of hard disks. Infection occurs when a system is booted from an infected floppy disk. It infects the system area of ​​the hard disk Master Boot Record (MBR). It is not necessary for the boot sequence to complete in order for this virus to execute.

When a computer is started with the infected hard disk, the virus resides in the system of the process to monitor the system operation of the user . It infects the boot sector of all writable areas of the floppy disk that is accessed.

  SOLUTION

Minimum Scan Engine:

9.750

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

Restore your system's Master Boot Record (MBR)

To restore your system's Master Boot Record (MBR):

• On Windows 2000, XP, and Server 2003:

  1. Insert your Windows Installation CD into your CD drive then restart your computer.
  2. When prompted, press any key to boot from the CD.
  3. On the Main Menu, type r to enter the Recovery Console.
    (Note for Windows 2000: After pressing r, type c to choose the Recovery Console on the repair options screen.)
  4. Type the number that corresponds to the drive and folder that contains Windows (usually C:\WINDOWS) and press Enter.
  5. Type your Administrator password and press Enter.
  6. In the input box, type the following then press Enter:
    fixmbr {affected drive}
  7. Type exit and press Enter to restart the system normally.

• On Windows Vista, 7, and Server 2008:

  1. Insert your Windows Installation DVD into the DVD drive, then press the restart button on your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to choose the installation language. On the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Repair your computer.
  4. Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
  5. If the Startup Repair window appears, click Cancel, Yes, then Finish.
  6. In the System Recovery Options menu, click Command Prompt.
  7. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  8. Type exit and press Enter to close the Command Prompt window.
  9. Click Restart to restart your computer normally.

• On Windows 8, 8.1, and Server 2012:

  1. Insert your Windows Installation DVD in the DVD drive, then restart your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to select the keyboard layout. Then on the Windows Setup window, choose your language, locale, and input method. Click Next, then click Repair your computer.
  4. Click Troubleshoot>Advanced Options>Command Prompt.
  5. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  6. Type exit and press Enter to close the Command Prompt window.
  7. Click Continue to restart the system normally.

Step 3

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