Modified by: Raighen Sanchez

ALIASES:

Virus:Win32/Grenam.VA!MSR (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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.

  TECHNICAL DETAILS

File Size: 534,016 bytes
File Type: EXE
Initial Samples Received Date: 31 Jan 2024
Payload: Deletes files, Drops files

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 drops the following copies of itself into the affected system:

  • %Application Data%/Ground.exe
  • {filepath of legitimate file}/{filename of legitimate file}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Trojan deletes the following files:

  • {original filename}.ico

Other Details

This Trojan does the following:

  • It renames legitimate files with g{original filename}.{original file extension}.
  • It hides legitimate files then replaces it with its own copy using the filename of the legitimate file.
  • It deletes files with the file extension .ico then drops its own copy in the same directory.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 14.808.05
FIRST VSAPI PATTERN DATE: 12 Feb 2019
VSAPI OPR PATTERN File: 14.809.00
VSAPI OPR PATTERN Date: 13 Feb 2019

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    •  TROJ.Win32.TRX.XXPE50FFF077

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 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.
  • %Application Data%/Ground.exe
  • {filepath of legitimate file}/{filename of legitimate file}.exe
  • {filepath of ico files}/RCXE{random}.tmp

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.GRENAM.SM. 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 the following Trend Micro Support pages for more information:


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