Analysis by: kathleenno
 ALIASES:

Backdoor.Tidserv (Symantec); Trojan:Win32/Meredrop (Microsoft); Trojan-Dropper.Win32.TDSS.agwv (Kaspersky)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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

Tipo de compactação: 127,488 bytes
Tipo de arquivo: EXE
Residente na memória: No
Data de recebimento das amostras iniciais: 20 Dec 2012
Carga útil: Receives information from remote users

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 copies of itself into the affected system:

  • %User Temp%\{random}.tmp

(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 and 7.)

NOTES:

It may connect to the following servers where it receives task from a remote malicious user:

  • https://{BLOCKED}reyk.com/
  • https://{BLOCKED}lewk.com/
  • https://{BLOCKED}chaa.com/
  • https://{BLOCKED}nona.com/
  • https://{BLOCKED}ay2k.com/
  • http://{BLOCKED}yawr.com/
  • http://{BLOCKED}wayr.com/
  • http://{BLOCKED}ut0.com/
  • http://{BLOCKED}o0.com/
  • http://{BLOCKED}uke.com/
  • http://{BLOCKED}i813ck.com/

To hide its component files, it writes the following files at the end of the hard disk:

  • \\?\globalroot\{random folder}\bckfg.tmp
  • \\?\globalroot\{random folder}\cfg.ini
  • \\?\globalroot\{random folder}\cmd.dll
  • \\?\globalroot\{random folder}\cmd64.dll
  • \\?\globalroot\{random folder}\drv32
  • \\?\globalroot\{random folder}\drv64
  • \\?\globalroot\{random folder}\ldr16
  • \\?\globalroot\{random folder}\ldr32
  • \\?\globalroot\{random folder}\ldr64
  • \\?\globalroot\{random folder}\mbr

  SOLUTION

Mecanismo de varredura mínima: 8.900
Primeiro arquivo padrão VSAPI: 7.988.01
Data do lançamento do primeiro padrão VSAPI: 18 Apr 2011

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as TROJ_TDSS.SMTS

[ 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 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_TDSS.SMTS. 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 this Knowledge Base page for more information.


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