PE_NESHTA.A

 Modified by: Augusto II Remillano

 ALIASES:

Virus:Win32/Neshta.A (Microsoft), Win32/Neshta.A virus (NOD32), Virus.Win32.Neshta.a (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Virus

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


This Virus arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It prepends its codes to target files.

  TECHNICAL DETAILS

File Size:

425,864 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Oct 2018

Payload:

Drops files

Arrival Details

This Virus 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 Virus drops the following files:

  • %Windows%\svchost.com → detected as PE_NESHTA.A-O
  • %User Temp%\3582-490\{Malware Filename} → clean version of infected file
  • %User Temp%\tmp5023.tmp

It adds the following processes:

  • %User Temp%\3582-490\{Malware Filename}

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %User Temp%\3582-490\

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • MutexPolesskayaGlush*.*{\xc2\x90}svchost.com\xc2\x90exefile\shell\open\command\xe2\x80\xb9\xc3\x80 "%1" %*\xc5\x93\xe2\x80\x98@

Other System Modifications

This Virus modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
exefile\shell\open\
command
(Default) = "%Windows%\svchost.com "%1" %*"

File Infection

This Virus infects the following file types:

  • EXE

It prepends its codes to target files.

It avoids infecting folders containing the following strings:

  • PROGRA~1
  • %Windows%
  • %Temp%

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

It avoids infecting files of the following sizes:

  • less than 41,472 bytes or greater than 10,000,000 bytes

This is the Trend Micro detection for files infected by:

  • PE_NESHTA.A-O

Other Details

This Virus does the following:

  • It avoids infecting files from the following drives:
    • CD-ROM
    • A:\
    • B:\

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

5.883.00

FIRST VSAPI PATTERN DATE:

08 Apr 2009

VSAPI OPR PATTERN File:

5.884.00

VSAPI OPR PATTERN Date:

09 Apr 2009

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.XXPE50FFF069

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

Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Classes\exefile\shell\open\command
    • From: (Default) = %Windows%\svchost.com "%1" %*"
      To: (Default) = "%1" %*"

Step 5

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.
  • %User Temp%\3582-490\{malware filename}
  • %User Temp%\tmp5023.tmp

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Temp%\3582-490

Step 7

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


Did this description help? Tell us how we did.