Analysis by: Jayvee Mark Villaroman
ALIASES:

Trojan:MSIL/AgentTesla.ABCU!MTB (MICROSOFT), MSIL/Spy.AgentTesla.D trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

File Size: 1,094,144 bytes
File Type: EXE
Memory Resident: Yes
Payload: Connects to URLs/IPs, Downloads files, Deletes files

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.

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
Default = %insregname%

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
StartupApproved\Run
Default = %insregname%

Other System Modifications

This Trojan Spy deletes the following files:

  • %System Root%\%insfolder%\%insname%:Zone.Identifier

Download Routine

This Trojan Spy downloads the file from the following URL and renames the file when stored in the affected system:

    • https://www.{BLOCKED}onrouter.com/dist.torproject.org/torbrowser/9.5.3/tor-win32-0.4.3.6.zip

It connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}.com/
    • As of this writing, the said sites are inaccessible.

It saves the files it downloads using the following names:

  • {File directory}/tor.zip
    • The malware installs and creates a hidden instance of Tor browser on the system and sets its proxy to 127.0.0.1:9050, the default listening port of Tor to route all connections through the Tor network and provide anonymity.

Information Theft

This Trojan Spy gathers the following data:

  • Current Time
  • Username
  • Computer Name
  • OS Fullname
  • CPU Information
  • RAM Information
  • IP Address
  • Credentials stored in Default Browser
  • Credentials stored in Windows Credential Files
  • Credentials from the following applications:
    • Browsers/Internet Suites:
    • 360Chrome
    • 7Star
    • Amigo
    • BlackHawk
    • Brave Browser
    • CentBrowser
    • Chedot
    • Citrio
    • Cốc Cốc Browser
    • Comodo Dragon
    • Comodo IceDragon
    • CoolNovo
    • Coowon
    • Cyberfox
    • Elements Browser
    • Epic Privacy Browser
    • Falkon
    • Flock Browser
    • Google Chrome
    • Iridium
    • K-Meleon
    • Kometa
    • Liebao Browser
    • Microsoft Edge
    • Mozilla Firefox
    • Mozilla Icecat
    • Mozilla SeaMonkey
    • Opera
    • Orbitum
    • Pale Moon
    • QIP Surf
    • QQBrowser
    • Safari Browser
    • Sleipnir
    • Sputnik
    • Torch Browser
    • UCBrowser
    • Uran
    • Vivaldi
    • Waterfox
    • Yandex Browser
  • Instant Messaging Applications:
    • Paltalk
    • Pidgin
    • Psi/Psi+
    • Trillian
  • Mail Clients:
    • Becky!
    • Claws Mail
    • eM Client
    • Eudora
    • Foxmail
    • IncrediMail
    • Mail Clients
    • Mailbird
    • Microsoft Outlook
    • Mozilla Thunderbird
    • Opera Mail
    • Pocomail
    • Postbox
    • The Bat!
  • File Transfer Software:
    • CFTP
    • CoreFTP
    • FileZilla
    • FlashFXP
    • FTP Navigator
    • FTPGetter
    • JDownloader
    • Internet Download Manager
    • No-IP
    • SmartFTP
    • WinSCP 2
    • WS_FTP
  • VPN Software:
    • NordVPN
    • OpenVPN
    • Private Internet Access VPN
  • VNC Software:
    • RealVNC
    • TigerVNC
    • TightVNC
    • UltraVNC
  • Miscellaneous:
    • Apple Keychain
  • It gathers credentials from the following vaults:
    • Windows Secure Note
    • Windows Web Password Credential
    • Windows Credential Picker Protector
    • Web Credentials
    • Windows Credentials
    • Windows Domain Certificate Credential
    • Windows Domain Password Credential
    • Windows Extended Credential
  • Motherboard Serial Number

It captures screenshots of the victim’s machines and saves it to an image file named:

  • {System Time+ "Screenshot" .jpeg} -> uploads directly to FTP server

Drop Points

This Trojan Spy uploads files to the following File Transfer Protocol (FTP) sites:

  • ftp://ftp.{BLOCKED}asthermovalve.cl

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.116.04
FIRST VSAPI PATTERN DATE: 06 Dec 2022
VSAPI OPR PATTERN File: 18.117.00
VSAPI OPR PATTERN Date: 07 Dec 2022

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:

    • Ransom.Win32.TRX.XXPE50FFF062

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

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.

Step 4

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

[ 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

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