Analysis by: Jeffrey Francis Bonaobra
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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: 79,808,592 bytes
File Type: EXE
Memory Resident: No

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 files:

  • %AppDataLocal%\Programs\PDFEditor\PDF Editor.exe → Detected as Trojan.Win64.EVILAI.YXFIL
  • %Start Menu%\Programs\PDF Editor.lnk
  • %Desktop%\PDF Editor.lnk

It adds the following processes:

  • %AppDataLocal%\Programs\PDFEditor\PDF Editor.exe

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

Autostart Technique

This Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
PDFEditorUpdater = "%AppDataLocal%\Programs\PDFEditor\PDF Editor.exe" --cm=--fullupdate

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\PDFEditor
InstallVersion = 1.0.26

HKEY_CURRENT_USER\SOFTWARE\{GUID}
InstallLocation = Type: REG_SZ, Length: 98, Data: %AppDataLocal%\Programs\PDFEditor

HKEY_CURRENT_USER\SOFTWARE\{GUID}
KeepShortcuts = true

HKEY_CURRENT_USER\SOFTWARE\{GUID}
ShortcutName = PDF Editor

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
DisplayName = PDF Editor 1.0.26

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
UninstallString = "%AppDataLocal%\Programs\PDFEditor\Uninstall PDF Editor.exe" /currentuser

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
QuietUninstallString = "%AppDataLocal%\Programs\PDFEditor\Uninstall PDF Editor.exe" /currentuser /S

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
DisplayVersion = 1.0.26

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
DisplayIcon = %AppDataLocal%\Programs\PDFEditor\uninstallerIcon.ico

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
Publisher = AppSuite

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
NoModify = 1

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
NoRepair = 1

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{GUID}
EstimatedSize = 270801

  SOLUTION

Minimum Scan Engine: 9.800
VSAPI OPR PATTERN File: 20.453.00
VSAPI OPR PATTERN Date: 12 Sep 2025

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

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\PDFEditor
    • InstallVersion = 1.0.26
  • In HKEY_CURRENT_USER\SOFTWARE\{GUID}
    • InstallLocation = Type: REG_SZ, Length: 98, Data: %AppDataLocal%\Programs\PDFEditor
  • In HKEY_CURRENT_USER\SOFTWARE\{GUID}
    • KeepShortcuts = true
  • In HKEY_CURRENT_USER\SOFTWARE\{GUID}
    • ShortcutName = PDF Editor
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • DisplayName = PDF Editor 1.0.26
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • UninstallString = "%AppDataLocal%\Programs\PDFEditor\Uninstall PDF Editor.exe" /currentuser
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • QuietUninstallString = "%AppDataLocal%\Programs\PDFEditor\Uninstall PDF Editor.exe" /currentuser /S
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • DisplayVersion = 1.0.26
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • DisplayIcon = %AppDataLocal%\Programs\PDFEditor\uninstallerIcon.ico
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • Publisher = AppSuite
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • NoModify = 1
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • NoRepair = 1
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{GUID}
    • EstimatedSize = 270801

Step 4

Search and delete these files

[ 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.
  • %AppDataLocal%\Programs\PDFEditor\PDF Editor.exe
  • %Start Menu%\Programs\PDF Editor.lnk
  • %Desktop%\PDF Editor.lnk

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.EVILAI.YXFH3. 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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