TROJ_VB.HJT

 Analysis by: Christopher Daniel So

 ALIASES:

Trojan.Win32.VB.etj (Kaspersky), W32/Emogen.ETJ!tr (Fortinet), Win32/VB.NPB trojan (Nod32)

 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

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies registry entries to disable various system services. This action prevents most of the system functions to be used.

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

13,312 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

Yes

Initial Samples Received Date:

28 Jan 2009

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This Trojan modifies registry entries to disable the following system services:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ALG
Start = 4

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess
Start = 4

(Note: The default value data of the said registry entry is 2.)

Process Termination

This Trojan terminates the following services if found on the affected system:

  • alg
  • SharedAccess

Download Routine

This Trojan connects to the following malicious URLs:

  • http://xxx.{BLOCKED}5.com/html/tongji.htm

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI OPR PATTERN File:

6.685.00

VSAPI OPR PATTERN Date:

11 Dec 2009

NOTES:

Trend customers:

    Keep your pattern and scan engine files updated. Trend Micro antivirus software can clean or remove most types of computer threats. Malware, though, such as Trojans, scripts, overwriting viruses and joke programs which are identified as uncleanable, should simply be deleted.

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  • Use HouseCall - the Trend Micro online threat scanner to check for malware that may already be on your PC.
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