TROJ_DROPPER.XTR

 Analysis by: Nikko Tamana

 ALIASES:

Trojan.Win32.Agent.hwkv (Kaspersky), Trojan:Win32/Comame (Microsoft), Win32/Agent.PKG trojan (NOD32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email


This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

  TECHNICAL DETAILS

File Size:

179,808 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

27 Dec 2012

Payload:

Drops files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\Del7.tmp - deletes the initially executed copy of the malware

(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.)

It drops the following file(s)/component(s):

  • {Malware Path}\謹賀新年.jpg
  • %Windows%\Tasks\svchost.exe - detected as BKDR_PROXY.XTQ

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

NOTES:

After execution, it opens {Malware path}\謹賀新年.jpg, a non-malicious image, to trick affected users into thinking they have opened a normal .JPG file.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.620.04

FIRST VSAPI PATTERN DATE:

27 Dec 2012

VSAPI OPR PATTERN File:

9.621.00

VSAPI OPR PATTERN Date:

28 Dec 2012

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

Remove the malware/grayware file dropped/downloaded by TROJ_DROPPER.XTR

Step 3

Search and delete the files detected as TROJ_DROPPER.XTR

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

For Windows Vista and Windows 7:

  1. Click Start>Computer.
  2. In the Search Computer input box, type the name of the file detected earlier, and press Enter.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 4

Search and delete this file

[ Learn More ]
There may be some 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.
  • {Malware Path}\謹賀新年.jpg

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPER.XTR. 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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