TrojanSpy.MSIL.NEGASTEAL.DYSGXT

August 06, 2020
 Analysis by: Patrick Noel Collado
 ALIASES:

Trojan:MSIL/Formbook.MK!MTB (Microsoft), HEUR:Trojan.MSIL.Crypt.gen (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

This Trojan Spy arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be downloaded by embedded scripts in email messages.

It logs a user's keystrokes to steal information.

  TECHNICAL DETAILS

File Size:

1,511,424 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Aug 2020

Arrival Details

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

It may be downloaded by embedded scripts in email messages.

Installation

This Trojan Spy drops the following copies of itself into the affected system:

  • %Application Data%\{Random Characters}\{Random Characters}.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).)

It adds the following processes:

  • {Malware Path}\{Malware Name}.exe "{path}"

Autostart Technique

This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random Characters} = %Application Data%\{Random Characters}\{Random Characters].exe

Information Theft

This Trojan Spy gathers the following data:

  • Username
  • Computer name
  • Processor Info
  • Amount of Memory
  • OS Name
  • Keylogger
  • Clipboard data
  • Credentials from:
    • BlackHawk
    • CyberFox
    • Flock
    • IceCat
    • IceDragon
    • KMeleon
    • Mozilla
    • PaleMoon
    • Postbox
    • SeaMonkey
    • Thunderbird
    • WaterFox
    • Orbitum
    • Iridium
    • Vivaldi
    • QIP Surf
    • Coowon
    • Torch
    • Chromium
    • Sputnik
    • Chedot
    • Kometa
    • Elements
    • Coccoc
    • Uran
    • 7Star
    • Epic Privacy
    • Liebao
    • Citrio
    • Chromium
    • CentBrowser
    • 360Chrome
    • Opera
    • Yandex
    • Comodo Dragon
    • Amigo
    • Brave
    • QQBroswer
    • Opera
    • Chrome
    • Claws Mail
    • Poco Mail
    • UCBrowser
    • Foxmail
    • Trilian
    • Apple

It logs a user's keystrokes to steal information.

Other Details

This Trojan Spy does the following:

  • Moves the original copy and rename it to %User Temp%\tmp{Random}.tmp

(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).)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

16.134.05

FIRST VSAPI PATTERN DATE:

22 Jul 2020

VSAPI OPR PATTERN File:

16.135.00

VSAPI OPR PATTERN Date:

23 Jul 2020

Step 1

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 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

Restart in Safe Mode

[ Learn More ]

Step 4

Identify and terminate files detected as TrojanSpy.MSIL.NEGASTEAL.DYSGXT

[ 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 5

Delete this 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {Random Characters} = %Application Data%\{Random Characters}\{Random Characters}.exe

Step 6

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%\{Random Characters}\{Random Characters}.exe
  • %User Temp%\tmp{Random}.tmp

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TrojanSpy.MSIL.NEGASTEAL.DYSGXT. 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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