TROJ_DLOADR.ZZD

Malware type: Trojan

Aliases: No Alias Found

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 98, ME, NT, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:

Medium

Distribution potential:

Low

Description: 

This Trojan has received attention from independent media sources and/or other security firms.

To get a one-glance comprehensive view of the behavior of this malware, refer to the Behavior Diagram shown below.

TROJ_DLOADR.ZZD Behavior Diagram

Malware Overview

This Trojan may be dropped by other malware. It may be downloaded unknowingly by a user when visiting malicious Web site(s).

It accesses a certain website to download an RSS feed. It saves the downloaded file in the current user's Temporary folder using a certain file name. However, the said site is currently inaccessible. The downloaded file may contain links where this Trojan downloads other files.

It then creates a registry entry to enable the automatic execution of one of the downloaded files. It also attempts to access another website to check for updates for the said RSS feed.

It attempts to download a file from a certain website. As a result, routines of the downloaded file are also exhibited on the affected system.

For additional information about this threat, see:

Description created: Aug. 21, 2009 12:22:35 AM GMT -0800


TECHNICAL DETAILS


File type: PE

Memory resident:  No

Size of malware: 89,088 Bytes

Initial samples received on: Aug 14, 2009

Payload 1: Downloads files

Details:

This Trojan may be dropped by other malware.

It may be downloaded unknowingly by a user when visiting malicious Web site(s).

It accesses the following website to download an RSS feed:

  • http://{BLOCKED}r.com/statuses/user_timeline/62798520.rss

It saves the downloaded file as %User Temp%\__{random number}.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.)

However, the said site is currently inaccessible.

The downloaded file may contain links where this Trojan may download other files.

The said files may be saved as the following files:

  • %User Temp%\{random numbers}\gbpm.exe
  • %User Temp%\{random numbers}\gbpm.dll

It then creates the following registry entry to enable the automatic execution of the file gbpm.exe:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
(Default) = "%User Temp%\{random numbers}\gbpm.exe"

It also attempts to access the following website to check for updates for the said RSS feed:

  • http://{BLOCKED}3.jaiku.com/rss

It also attempts to download a file from the following website:

  • http://{BLOCKED}lt.freehostia.com/first/post.php?user{user name}&name={name of the machine}&winver={windows version}&MAC=&reason=INFECT

As a result, routines of the downloaded file are also exhibited on the affected system.

This Trojan runs on Windows 98, ME, NT, 2000, XP, and Server 2003.


Analysis By: Jasper Manuel

Revision History:

First pattern file version: 6.366.07

SOLUTION


Minimum scan engine version needed: 8.700

Pattern file needed: 6.377.00

Pattern release date: Aug 19, 2009


Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.

Solution:

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

 Step 1:  Delete this registry value  [learn how]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
    CurrentVersion\Run
    • (Default) = "%User Temp%\{random numbers}\gbpm.exe"

 Step 2: Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.ZZD  

*Note: 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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