Analysis by: Michael Cabel
ALIASES:

Microsoft: Backdoor:Win32/Agent.DT; Kaspersky: Trojan-Downloader.Win32.Agent.wqs

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

It terminates and disables the security-related processes.

This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

However, as of this writing, the said sites are inaccessible. It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 7,896 bytes
File Type: PE
Memory Resident: No
Initial Samples Received Date: 29 Jan 2011
Payload: Terminates processes, Connects to URLs/Ips

Arrival Details

This Trojan may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}aile1.com/a.dat

However, as of this writing, the said sites are inaccessible.

It deletes itself after execution.

NOTES:

It terminates and disables the following security-related processes:

  • ekrn.exe
  • egui.exe
  • nod32krn.exe
  • nod32kui.exe

It does the said routine by executing the following commands in the command line:

sc config ekrn start= disabled
sc config NOD32krn start= disabled
taskkill /im ekrn.exe /f
taskkill /im egui.exe /f
taskkill /im nod32krn.exe /f
taskkill /im nod32kui.exe /f

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.800.06
VSAPI PATTERN Date: 29 Jan 2011
VSAPI PATTERN Date: 1/29/2011 12:00:00 AM

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

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.LTW. 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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