Analysis by: Lord Alfred Remorin
 ALIASES:

Backdoor:Win32/Swami.A (Microsoft), Trojan.Gen.2 (Symantec)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Canal de infecção: Dropped by other malware

This backdoor may be dropped by other malware.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

Tipo de compactação: 90,112 bytes
Tipo de arquivo: EXE
Residente na memória: Yes
Data de recebimento das amostras iniciais: 11 Aug 2012
Carga útil: Connects to URLs/IPs

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_ARTIEF.TIB

Installation

This backdoor drops and executes the following files:

  • %Application Data%\SVCH0ST.exe - also detected as BKDR_SWAMI.A

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
SysUpdate = "%Application Data%\SVCH0ST.exe"

Download Routine

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

  • http://dplcoopsociety.us.{BLOCKED}u.com/im/linux.php
  • http://dplcoopsociety.us.{BLOCKED}u.com/im/solaris.php
  • http://dplcoopsociety.us.{BLOCKED}u.com/im/freebsd.php

It saves the files it downloads using the following names:

  • %Application Data%\syswmi.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

As of this writing, the said sites are inaccessible.

  SOLUTION

Mecanismo de varredura mínima: 9.200
Primeiro arquivo padrão VSAPI: 9.318.02
Data do lançamento do primeiro padrão VSAPI: 13 Aug 2012
VSAPI OPR Pattern Version: 9.319.00
VSAPI OPR Pattern veröffentlicht am: 13 Aug 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware files dropped/downloaded by BKDR_SWAMI.TIB

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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\Microsoft\Windows\CurrentVersion\Run
    • SysUpdate = "%Application Data%\SVCH0ST.exe"

Step 5

Search and delete this file

[ Learn More ]
There may be some component 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.
  • %Application Data%\SVCH0ST.exe
  • %Application Data%\syswmi.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SWAMI.TIB. 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.

Step 7

Scan your computer with your Trend Micro product to delete files detected as BKDR_SWAMI.TIB. 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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