Analysis by: Rhena Inocencio
 PLATFORM:

Windows XP (64-bit), Windows Vista (64-bit), Windows 7 (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: Dropped by other malware, Downloaded from the Internet, Bundled with malware packages as a malware component

This malware is injected into certain processes in order to download and execute malware. The malicious routines of the downloaded malware may be exhibited on the affected system.

This Trojan may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It exports functions used by other malware. It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: 75,264 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 06 Feb 2013
Payload: Downloads files

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

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

Download Routine

This Trojan accesses the following websites to download files:

  • http://www.{BLOCKED}wer.com/srilk/TomAndJerry.jpg

It saves the files it downloads using the following names:

  • %User Temp%\{random file name}.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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan exports functions used by other malware.

It requires its main component to successfully perform its intended routine.

NOTES:

TROJ64_INSTOL.USR passes the encrypted URL to this DLL component.

This DLL component has only one export function named ExportFunc which is repeatedly executed.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.708.08
FIRST VSAPI PATTERN DATE: 06 Feb 2013
VSAPI OPR PATTERN File: 9.709.00
VSAPI OPR PATTERN Date: 06 Feb 2013

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

Scan your computer with your Trend Micro product and note files detected as TROJ64_INJECT.USR

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the file detected as TROJ64_INJECT.USR

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ64_INJECT.USR. 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.

NOTES:

Please perform this step before proceeding to Step 5:

  • Identify and delete the main malware component detected as TROJ64_INSTOL.USR


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