TROJANSPY.WIN32.TEAMFOSTEALER.THOABAAI

 Analysis by: Patrick Angelo Roderno

 ALIASES:

Backdoor.Win32.TeamBot.hv (KASPERSKY); W32/TeamBot.HV!tr.bdr (FORTINET); Trojan:Win32/Zpevdo.A (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

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.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

3998591 bytes

File Type:

EXE

File Compression:

Themida

Memory Resident:

No

Initial Samples Received Date:

28 Nov 2018

Payload:

Connects to URLs/IPs, Executes 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.

Installation

This Trojan Spy drops the following files:

  • %User Temp%\PmIgYzA\FZhIG.ico
  • %User Temp%\PmIgYzA\config.bin
  • %User Temp%\PmIgYzA\0.0
  • %User Temp%\PmIgYzA\TV.dll (malicious payload)
  • %User Startup%\Gateway Layer 1.3957.lnk (shortcut link to dropped TeamViewer.exe)

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It drops the following non-malicious files:

  • %User Temp%\PmIgYzA\TeamViewer.exe
  • %User Temp%\PmIgYzA\TeamViewer_Resource_fr.dll

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It creates the following folders:

  • %User Temp%\PmIgYzA

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

Information Theft

This Trojan Spy gathers the following data:

  • Operating System
  • OS Architecture
  • Computer Name
  • User Name
  • RAM size
  • Presence of AV Products
  • Administrator Privilege

Other Details

This Trojan Spy connects to the following website to send and receive information:

  • http://{BLOCKED}s32.com/3307

It does the following:

  • It executes the EXE file %User Temp%\PmIgYzA\TeamViewer.exe which loads the malicious DLL %User Temp%\PmIgYzA\TV.dll

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.764.03

FIRST VSAPI PATTERN DATE:

21 Jan 2019

VSAPI OPR PATTERN File:

14.765.00

VSAPI OPR PATTERN Date:

22 Jan 2019

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

Identify and terminate files detected as TROJANSPY.WIN32.TEAMFOSTEALER.THOABAAI

[ 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 4

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %User Temp%\PmIgYzA

Step 5

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.  
  • %User Startup%\Gateway Layer 1.3957.lnk

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJANSPY.WIN32.TEAMFOSTEALER.THOABAAI. 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:


Did this description help? Tell us how we did.