Analysis by: kathleenno
ALIASES:

Trojan.Win32.TDSS.bzbb (Kaspersky); Generic Dropper.va.gen.p (Mcafee_Beta); W32/TDSS.ADU!tr (Fortinet)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor 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: Varies
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Mar 2011
Payload: Steals information

Arrival Details

This backdoor 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 backdoor 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:
This Trojan 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://u101mnay2k.com/
  • http://gnarenyawr.com/
  • http://rinderwayr.com/
  • http://jukdoout0.com/
  • http://{BLOCKED}o0.com/
  • http://{BLOCKED}yuke.com/
  • http://{BLOCKED}i813ck.com/

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.939.00
FIRST VSAPI PATTERN DATE: 30 Mar 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 BKDR_TDSS.SMZ

[ 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 BKDR_TDSS.SMZ. 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.


Did this description help? Tell us how we did.