Analysis by: Janus Agcaoili
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This Trojan may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 19,456 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 20 Apr 2016
Payload: Deletes files

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It 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 drops and executes the following files:

  • %ProgramData%\MicrobenchGPU\del.bat <- component responsible for deleting both itself and TROJ_DELSAM.G after executing its routine

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Other Details

This Trojan does the following:

  • Checks and deletes folders containing the string 'backup' from every directory in the system
  • Checks and deletes backup files with the following file extensions from every directory in the system:
    • .dmp
    • .v2i
    • .abk
    • .ac
    • .back
    • .backup
    • .backupdb
    • .bak
    • .bb
    • .bk
    • .bkc
    • .bke
    • .bkf
    • .bkn
    • .bkp
    • .bpp
    • .bup
    • .cvt
    • .dbk
    • .dtb
    • .fb
    • .fbw
    • .fkc
    • .jou
    • .mbk
    • .old
    • .rpb
    • .sav
    • .sbk
    • .sik
    • .spf
    • .spi
    • .swp
    • .tbk
    • .tib
    • .tjl
    • .umb
    • .vbk
    • .vib
    • .vmdk
    • .vrb
    • .wbk
  • Checks if they are being locked up by other processes, if so then it terminates those processes and proceeds to deleting the backup file

It deletes itself after execution.

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.800

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

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.  
  • %ProgramData%\MicrobenchGPU\del.bat

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DELSAM.G. 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 5

Restore files 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 your computer again.


Did this description help? Tell us how we did.