Threat Encyclopedia

TROJ_DLOAD.VAC

Publish date: October 08, 2012

PLATFORM:

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

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

  • Threat Type:

  • Destructiveness:No

  • Encrypted:

  • In the wild: Yes

OVERVIEW


TECHNICAL DETAILS

File Size:

Varies

Memory Resident:

Yes

Arrival Details

This Trojan may be downloaded from the following remote site(s):

  • http://{BLOCKED}int.us/log.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
smx4pnp = "rundll32.exe "%User Profile%\Microsoft\smx4pnp.dll", Launch"

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Microsoft\smx4pnp.dll - detected as TROJ_DLOAD.VAC

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Download Routine

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

  • http://d.{BLOCKED}s.us/u.txt

Trend Micro detects the dowloaded file as:

  • http://d.{BLOCKED}s.us/ma.exe - detected as TSPY_GAMETHI.QJB

SOLUTION

Minimum Scan Engine:

8.900

Step 1

Restart in Safe Mode

[ Learn More ]

Step 2

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
    • smx4pnp = rundll32.exe %User Profile%\Microsoft\smx4pnp.dll, Launch

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOAD.VAC. 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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