Analysis by: Neljorn Nathaniel Aguas
ALIASES:

Trojan:MSIL/AgentTesla.KKAA!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: No

  • 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.

It does not have any propagation routine.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size: 240,128 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 17 Dec 2025

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.

Propagation

This Trojan Spy does not have any propagation routine.

Backdoor Routine

This Trojan Spy does not have any backdoor routine.

Rootkit Capabilities

This Trojan Spy does not have rootkit capabilities.

Information Theft

This Trojan Spy gathers the following data:

  • System Information:
    • Computer name
    • Username
    • OS version
    • Network configuration
    • IP address
  • Browser Credentials:
    • Google Chrome
    • Mozilla Firefox
    • Microsoft Edge
    • Opera
    • Brave
    • Chromium
    • Vivaldi
    • Yandex Browser
    • 360 Browser
    • CentBrowser
    • Chedot
    • Citrio
    • Coowon
    • CocCoc Browser
    • Comodo Dragon
    • Comodo IceDragon
    • CoolNovo
    • Cyberfox
    • Elements Browser
    • Epic Privacy Browser
    • Flock Browser
    • Iridium Browser
    • K-Meleon
    • Kometa
    • Liebao Browser
    • Maxthon
    • Orbitum
    • Pale Moon
    • QIP Surf
    • QQ Browser
    • SeaMonkey
    • Sleipnir
    • SRWare Iron
    • Torch Browser
    • UC Browser
  • FTP Client Credentials:
    • FileZilla
    • WinSCP
    • CoreFTP
    • SmartFTP
    • FTPGetter
    • FTP Navigator
    • FlashFXP
    • FTPCommander
    • Cyberduck
    • WS_FTP
  • Email Client Credentials:
    • Microsoft Outlook
    • Mozilla Thunderbird
    • Foxmail
    • Opera Mail
    • PocoMail
    • IncrediMail
    • Becky! Internet Mail
    • The Bat!
    • Postbox
    • Mailbird
    • eM Client
    • Claws Mail
    • Windows Mail
    • Windows Live Mail
    • Gmail Notifier Pro
    • Yahoo! Mail
  • VPN Client Credentials:
    • OpenVPN
    • NordVPN
  • VNC Client Credentials:
    • RealVNC
    • TightVNC
    • UltraVNC
  • Other Credentials:
    • Discord tokens
    • Telegram session data
    • Pidgin (IM client)

Stolen Information

This Trojan Spy sends the data it gathers to the following email addresses via SMTP:

  • {BLOCKED}@gmail.com
  • {BLOCKED}@pgsu.co.id

Drop Points

This Trojan Spy uses its own SMTP engine to send the stolen data using the following domain server:

  • {BLOCKED}.co.id:587

Other Details

This Trojan Spy connects to the following URL(s) to get the affected system's IP address:

  • https://account.{BLOCKED}.com

It does the following:

  • It reads the following files to gather credentials:
    • %Application Data%\FileZilla\recentservers.xml
    • %Application Data%\FileZilla\sitemanager.xml
    • %Application Data%\FTPGetter\servers.xml
    • %Application Data%\SmartFTP\Client 2.0\Favorites\Quick Connect
    • %Application Data%\Mozilla\Firefox\profiles.ini
    • %Application Data%\Opera Software\Opera Stable\Login Data
    • %Application Data%\Thunderbird\profiles.ini
    • %Application Data%\Foxmail\mail\
    • %Application Data%\discord\Local Storage\leveldb\
    • %AppDataLocal%\Google\Chrome\User Data\Local State
    • %AppDataLocal%\Google\Chrome\User Data\Default\Login Data
    • %AppDataLocal%\Google\Chrome\User Data\Default\Web Data
    • %AppDataLocal%\Microsoft\Edge\User Data\Default\Login Data
  • It queries the following registry keys to gather credentials:
    • HKEY_CURRENT_USER\SOFTWARE\Martin Prikryl\WinSCP 2\Sessions
    • HKEY_CURRENT_USER\SOFTWARE\FTPWare\COREFTP\Sites
    • HKEY_CURRENT_USER\Software\Microsoft\Windows Messaging Subsystem\Profiles\9375CFF0413111d3B88A00104B2A6676
    • HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles
    • HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Profiles
    • HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Profiles
    • HKEY_CURRENT_USER\Software\RimArts\B2\Settings
    • HKEY_CURRENT_USER\Software\RealVNC\WinVNC4
    • HKEY_CURRENT_USER\Software\TightVNC\Server
    • HKEY_CURRENT_USER\Software\TigerVNC\WinVNC4
  • It captures keystrokes using a low-level keyboard hook.
  • It monitors clipboard content for copied passwords and sensitive data.
  • It periodically captures screenshots of the desktop.

(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).)

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 20.648.02
FIRST VSAPI PATTERN DATE: 17 Dec 2025
VSAPI OPR PATTERN File: 20.649.00
VSAPI OPR PATTERN Date: 18 Dec 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

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.MSIL.NEGASTEAL.TCLRYNAA. 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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