TrojanSpy.MSIL.NEGASTEAL.DYSGVA
TScope.Trojan.MSIL (VBA32); a variant of MSIL/Kryptik.VGP trojan (NOD32)
Windows
Threat Type: Trojan Spy
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
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.
Installation
This Trojan Spy adds the following folders:
%Application Data%\rsSspWJ
(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 drops a copy of itself in the following folders using different file names:
- %Application Data%\pcname1.exe
- %Application Data%\rsSspWJ\GkaTp.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:
- "cmd.exe" /c REG ADD HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run /f /v application /t REG_SZ /d %System%\pcalua.exe" -a %Application Data%\pcname1.exe"
- %System%\pcalua.exe -a %Application Data%\pcname1.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).)
Autostart Technique
This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:
HKCU\Software\Microsoft\
Windows\CurrentVersion\Run
pmabpGZN = %Application Data%\rsSspWJ\GkaTp.exe
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
application = %System%\pcalua.exe -a %Application Data%\pcname1.exe
SOLUTION
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:
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
Delete this registry value
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
Step 5
Delete this registry value
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
Step 6
Search and delete these files
- %Application Data%\pcname1.exe
- %Application Data%\rsSspWJ\GkaTp.exe
Step 7
Search and delete this folder
- %Application Data%\rsSspWJ
Step 8
Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.MSIL.NEGASTEAL.DYSGVA. 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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